Need 2s Lipo Recommendation

[jackjohnson]

I have decided to purchase a 2s lipo. I feel it will have better control for me, and I can go off-roading on stock gearing without worrying about frying anything. Can anyone recommend a good pack? I prefer a high mah rating for longer run times. A higher charging rate for faster charging would be great too. I also don't want to spend more than $100 on it if possible. I would prefer that it come with the Traxxas connector already soldered, but it's not a dealbreaker. Here is the pack I'm looking at now:

SMC Sport Max LiPo 7.4V 6000mAh 28C Hard Case Traxxas
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXXFZ7&P=0

I have also looked at this pack for the higher mah rating (and it's cheaper):

Venom LiPo 2S 2P 7.4V 8000mAh 25C R/C Car Univ System
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXXLJ2&P=0

I don't want to get a battery that is completely overkill (ie. way more amps than the motor/esc can even use), but I'm not even sure of the amperage of those components. Any recommendations would be greatly appreciated!

[rcmonkey]

I went with promatchracing.com packs. I got two 2s 5000mah 25c for around $80 and get great run times and power.

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[Grand National]

There are some eBay people that sell Blue LiPo's with Traxxas connectors already soldered on them, and Blue LiPos are great IMO!

http://cgi.ebay.com/Blue-LiPo-2s-5000-mAh-30c-w-Traxxas-Plug-E-MAXX-Revo-/320645972305?pt=Radio_Control_Parts_Accessories&hash=item4aa7fd4151

There are also people on eBay selling Zippies and those are a good buy too!

[jackjohnson]

I went with promatchracing.com packs. I got two 2s 5000mah 25c for around $80 and get great run times and power.

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Wow those are cheap at $40 a pop. Will I notice much of a difference between those packs and the SMC or Venom? What about the Promatch 50c - is that worth it for $70?

[rcmonkey]

I was going to say blue lipos too but have no experience with them. Pretty cheap at hobby partz, but aren't they soft case? Promatch will solder on any connector, are hardcase, and by all accounts great customer service. I can't comment on other batts as these are the only lipos I have. Maybe someone else will chime in on the other questions

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[dugsagun]

I recently bought a sky lipo 2s 40c 3000mah pack from hobbypartz.com for around 18 bucks and i'm really liking it in my pede'. It's so much more controllabe then a 3s pack and is still plenty fast. You have to solder on traxxas connectors , but hey, if I can do it with a crappy 25 watt soldering iron , anyone can, heh.

[jackjohnson]

I recently bought a sky lipo 2s 40c 3000mah pack from hobbypartz.com for around 18 bucks and i'm really liking it in my pede'. It's so much more controllabe then a 3s pack and is still plenty fast. You have to solder on traxxas connectors , but hey, if I can do it with a crappy 25 watt soldering iron , anyone can, heh.

How long are your run times on a 3000mah?

[P'noRcer]

does it have to be top of the line?
racers edge makes a really good 2s 25 5000mah battery for $48 bucks and its a great battery!!

[P'noRcer]

There are some eBay people that sell Blue LiPo's with Traxxas connectors already soldered on them, and Blue LiPos are great IMO!

http://cgi.ebay.com/Blue-LiPo-2s-5000-mAh-30c-w-Traxxas-Plug-E-MAXX-Revo-/320645972305?pt=Radio_Control_Parts_Accessories&hash=item4aa7fd4151


There are also people on eBay selling Zippies and those are a good buy too!
i found the same battery for a little less then on the bay!!:)
http://www.hobbypartz.com/83p-5000mah-2s1p-74-30c-car.html

[Shadow7g]

I like my ******* 2s 5000!

[Geodude85]

There are some eBay people that sell Blue LiPo's with Traxxas connectors already soldered on them, and Blue LiPos are great IMO!

http://cgi.ebay.com/Blue-LiPo-2s-5000-mAh-30c-w-Traxxas-Plug-E-MAXX-Revo-/320645972305?pt=Radio_Control_Parts_Accessories&hash=item4aa7fd4151

There are also people on eBay selling Zippies and those are a good buy too!

Blue lipos are great, but that seller is asking an $18 markup on those batteries. It's better if you just buy them yourself and solder it on.

http://www.hobbypartz.com/83p-5000mah-2s1p-74-30c.html

Same battery, free shipping. You will have to solder the TRX connector on though.

I personally have these and haven't had a single problem with them yet. They've even outlasted my SPC lipos.

http://www.hobbypartz.com/83p-5000mah-2s1p-74-20c.html

$20 a pop for 5000 mah 20 C batteries. That's all I need for bashing. They are a tight squeeze though. If you're concerned with them being too tight of a squeeze since they're softcase, you can get these:

http://www.hobbypartz.com/77p-sl5000-2s1p-20c-2222.html

Also $20 each, and they should fit no problem, although I haven't tried them personally myself yet.

Edit: Oh, and they all ship from within the US. None of them are from Hong Kong.

[Geodude85]

i found the same battery for a little less then on the bay!!:)
http://www.hobbypartz.com/83p-5000mah-2s1p-74-30c-car.html

I would like to get those too, but they're always out of stock lol.

[jackjohnson]

So will this hard case version fit?
http://www.hobbypartz.com/83p-5000mah-2s1p-74-30c-car.html

I have to say, $25 for a 5000mah 30c 2s is a pretty hard deal to beat.

[rockdzl]

I have read here and other forums that it might be a good idea to go with 25C or higher output rating. Is this true? I'm thinking to get some blue lipos, 2s 5000 mah 25C or 30C.

[sandblaster]

Best bang for buck just maybe the ******* 5000 40C hard case out of the US warehouse. Search for ******* 5000 40c to find the source. The few extra bucks for the 40c are very worth will. They have much better punch then the lighter C rated batteries.

[jackjohnson]

Best bang for buck just maybe the ******* 5000 40C hard case out of the US warehouse. Search for ******* 5000 40c to find the source. The few extra bucks for the 40c are very worth will. They have much better punch then the lighter C rated batteries.

Do they fit though? I compared some to the stock battery tray dimensions (142mm x 48.5mm x 23mm), and they were too big.

[jackjohnson]

What about this Gens Ace? It's 5300mah, 25c, and charges at a 5c rate. Plus it's only $33. Anyone use Gens Ace before?

http://www.hobbypartz.com/98p-30c-5300-2s1p.html

[Geodude85]

So will this hard case version fit?
http://www.hobbypartz.com/83p-5000mah-2s1p-74-30c-car.html

I have to say, $25 for a 5000mah 30c 2s is a pretty hard deal to beat.

Yes, it'll fit.

[jackjohnson]

Yes, it'll fit.

Great! Now where can I buy it? :)

[zerolatency79]

Best bang for buck just maybe the ******* 5000 40C hard case out of the US warehouse. Search for ******* 5000 40c to find the source. The few extra bucks for the 40c are very worth will. They have much better punch then the lighter C rated batteries.

Not totally true.

I have:
3s
******* 3600 x 30c (40c burst) = 108A (144A burst)
Venom 5400 x 20c (40c burst) = 108A (216A burst)

2s
******* HC 4000 x 30c (40c burst) = 120A (160a burst)
Dynamite HC 5300 x 25c (n/a) = 132.5A
SMC HC 5200 x 24c (n/a) = 124.8A

Given they they are the same number of cells they all run the same. If you noticed they all have one thing in common. They can all run over 100A continuous. With a stock traxxas vxl system you will not gain anything by going over 100A, this is the max that the motor can draw. Yes the ESC is rated much higher but if the motor won't draw it, there is no need to be able to supply it. General rule of thumb for maximum battery life is to not run constantly over 80% of the rated amperage capacity which i realize the 108A and 120A batteries do not cover the 80% rule but real world, when are you ever over 80% load for the entire race? Save the extra money....

Don't believe me?

http://www.traxxas.com/sites/default/files/3351_3350X_manual.pdf

Page 10

[jackjohnson]

Not totally true.

I have:
3s
******* 3600 x 30c (40c burst) = 108A (144A burst)
Venom 5400 x 20c (40c burst) = 108A (216A burst)

2s
******* HC 4000 x 30c (40c burst) = 120A (160a burst)
Dynamite HC 5300 x 25c (n/a) = 132.5A
SMC HC 5200 x 24c (n/a) = 124.8A

Given they they are the same number of cells they all run the same. If you noticed they all have one thing in common. They can all run over 100A continuous. With a stock traxxas vxl system you will not gain anything by going over 100A, this is the max that the motor can draw. Yes the ESC is rated much higher but if the motor won't draw it, there is no need to be able to supply it. General rule of thumb for maximum battery life is to not run constantly over 80% of the rated amperage capacity which i realize the 108A and 120A batteries do not cover the 80% rule but real world, when are you ever over 80% load for the entire race? Save the extra money....

Don't believe me?

http://www.traxxas.com/sites/default/files/3351_3350X_manual.pdf

Page 10

I'm only asking this because I'm a battery newb, and I'm not sure of the answer. If you can't gain anything by going over 100a continuous, then why did you get batteries that are 120, 124, and 132a? Is there no benefit to those more expensive batteries? I read somewhere that while the motor is rated at 100a, it can actually take more in burst. Is that true?

[jlo767]

I've been using 2 different hardcase "budget" 2s lipos for bashing in the 4x4 and would recommend either one. Both are ******* from the USA warehouse for $19.99 each. They both fit into the battery tray with no modifications, but you will need to add your own plugs. They come with bullet style plugs and large 10 guage wire. I use Deans plugs which are no problem to solder on, but I'm not sure how difficult it is to squeeze the larger guage wire into the Traxxas connector.
One is 4000mah, 30-40c: Product=14988
The other is 5000mah, 20-30c: Product=14976
Both are about identical size, the 4000 has a little more punch and the 5000 has a little more run time. I'm not racing with these packs so I don't have any detailed performance numbers but they are the best value lipo I have used.

[zerolatency79]

I'm only asking this because I'm a battery newb, and I'm not sure of the answer. If you can't gain anything by going over 100a continuous, then why did you get batteries that are 120, 124, and 132a? Is there no benefit to those more expensive batteries? I read somewhere that while the motor is rated at 100a, it can actually take more in burst. Is that true?

Although i don't claim to have seen everyone's data logs, the highest pull i've seen on the VXL motor is 103A in burst. The motor is actually rated at 65A continuous 100A burst. The reason for the amperages shown on the batteries is that you'll never get it perfect. It is better to have more than less no doubt but at a certain level it becomes all to unnecessary. If i would have bought the 2s *******'s at a 20c instead i wouldn't have had enough to cover the 100A requirement. It is better to have more than less no doubt but at a certain level it becomes all to unnecessary. The 5000 40c previously recommended would have a 200A rating which is double what the motor suposedly draws at a max.

When i look for a battery here are my requirements:
1. Amps >=100 (more is better but not worth more money)
To calculate this its .001 x MAH rating (the 1000's number) x C rating ( I.E (.001x4000mah)x30c=120A )
2. mah - how longs this thing going to last? Generally the higher the number the longer it goes, the longer it takes to charge, the more it weighs.
3. Weight - this is a trade off, is a long lasting battery worth making your car heavier? (more important in extreme bashing and racing situations.. sometimes, but rarely, weight is better...)

[sandblaster]

For battery weight, check out this interesting thread.


http://traxxas.com/forums/showthread.php?8901573-Recommendation-for-second-set-of-lipo-s

[jucs]

What about SPC lipo's?

[Geodude85]

I've been using 2 different hardcase "budget" 2s lipos for bashing in the 4x4 and would recommend either one. Both are ******* from HK USA warehouse for $19.99 each. They both fit into the battery tray with no modifications, but you will need to add your own plugs. They come with bullet style plugs and large 10 guage wire. I use Deans plugs which are no problem to solder on, but I'm not sure how difficult it is to squeeze the larger guage wire into the Traxxas connector.
One is 4000mah, 30-40c: Product=14988
The other is 5000mah, 20-30c: Product=14976
Both are about identical size, the 4000 has a little more punch and the 5000 has a little more run time. I'm not racing with these packs so I don't have any detailed performance numbers but they are the best value lipo I have used.


Are these the packs you're talking about?

Edit: Woops, looks like Traxxas doesn't like me linking to their site.

They seem like a great deal too.

I wish these cheap lipos were around when I first joined into the hobby xD I would have saved so much money.

[Geodude85]

I'm only asking this because I'm a battery newb, and I'm not sure of the answer. If you can't gain anything by going over 100a continuous, then why did you get batteries that are 120, 124, and 132a? Is there no benefit to those more expensive batteries? I read somewhere that while the motor is rated at 100a, it can actually take more in burst. Is that true?

It's better to be safe than sorry, pretty much. I'm no battery expert, but I've been running nothing but 5000 mah 20 C (100 amp) packs in my VXL systems for over a year now, and I've never had a problem.

But. If you ever do decide to upgrade the Velineon motor to a more power hungry one, it's good to have those higher amp packs around ;)

[jackjohnson]

Thanks for all the inputs guys! This is starting to make a whole lot more sense to me now. Just to clarify from your posts...

It's better to go slightly over the amps required by the motor, but any more is overkill and will yield no performance benefit. For example, a 5000mah 30c (150a) or 5000mah 50c (250a) will provide no performance benefit whatsoever on my 100a motor over a 5000mah 25c (125a). And this holds true regardless of whether you are talking about a 2s, 3s, or other. Is that all correct?

[zerolatency79]

You've got it. I think i said it in one post, the best bet for battery life (longevity) is to use no more than 80% of the battery's max at a constant rate (this is more important for planes than it is here as they are running 80-100 throttle under normal conditions) but if you are the type of guy that just wants it for speed and goes full throttle back and forth down the street keep the 80% mark in mind.

This holds true reguardless of voltage. if you have a 5000mah 25c 3s and a 5000mah 50c 3s you'll have the same results, (provided the battery is operating as advertised) comparing 2s to 3s is completely different though.

[jackjohnson]

You've got it. I think i said it in one post, the best bet for battery life (longevity) is to use no more than 80% of the battery's max at a constant rate (this is more important for planes than it is here as they are running 80-100 throttle under normal conditions) but if you are the type of guy that just wants it for speed and goes full throttle back and forth down the street keep the 80% mark in mind.

This holds true reguardless of voltage. if you have a 5000mah 25c 3s and a 5000mah 50c 3s you'll have the same results, (provided the battery is operating as advertised) comparing 2s to 3s is completely different though.

Great, so if I understand correctly the ideal battery amperage for our motor (and to maintain battery life) then is 125a (.8 x 125a = 100a). If anything more is overkill, people should stick with 125a.

[zerolatency79]

perfect, the 125a will actually never be peaked entirely but with the life span of the pack in mind thats the direction i would go.

[jackjohnson]

I wish I would have waited then. I jumped the gun before truly understanding this and bought the pro-match 5000mah 50c. Since that's 250a, it's kind of a waste of money at $75. I may cancel the order and get something different. I honestly can't even find a 5000mah 25c that is cheaper than the 5200mah 30c ******* (at least that is in stock). I may just go with that since it's $24. Let me know if you think this is ok:

Also, I'm not sure what Traxxas part I need for the batt - do I just need the gold plated female trx connector? I have the Venom pro charger, but I'm not sure if it handes the JST-XH balancing plug (it's at home and the manual sucks). Anyone know?

Thanks guys.

Edited for Content
-ksb51rl

[zerolatency79]

The traxxas part for the battery ends is either the 3060 which is one male/one female or the 3080 which is 2 female.

You don't have to go crazy with matching the amperage, if 30c what you see then go that route, it really comes down to price, if for some reason you would find same brand same mah but a higher c rating for the same or less money go for it. A high C rating won't hurt you, but there is a point where it becomes useless.

I can't say for sure on the venom pro charger, the only thing i can tell you is that the venom battery i have has the jst-xh balancing plug on it. Based on that i would assume that their brand of chargers would be jst-xh...

FYI: links to outside vendors won't post, its a traxxas site, they don't want to steer business away.

Total garbage. Get your facts straight.
-ksb51rl

[jackjohnson]

The traxxas part for the battery ends is either the 3060 which is one male/one female or the 3080 which is 2 female.

You don't have to go crazy with matching the amperage, if 30c what you see then go that route, it really comes down to price, if for some reason you would find same brand same mah but a higher c rating for the same or less money go for it. A high C rating won't hurt you, but there is a point where it becomes useless.

I can't say for sure on the venom pro charger, the only thing i can tell you is that the venom battery i have has the jst-xh balancing plug on it. Based on that i would assume that their brand of chargers would be jst-xh...

Awesome, thank you. Now to change out the plug, I just cut off the old plugs with wire cutters and solder the traxxas female connector on the end, correct? Why can't I just use something an adapter like #604BCC-HCLB on hobby king and avoid soldering altogether?

[zerolatency79]

I've tried to look for an adapter myself but never found one. I don't know quite as much in this department, as the reason i know a lot about the batteries is quite frankly lipos scared the crap out of me so i wanted to know everything i could about them before starting to use them.

What i've seen posted in the past is that through adapters you will probably have power loss no matter how good the connection may be, so most everyone solders on the new connector.

[jackjohnson]

I've tried to look for an adapter myself but never found one. I don't know quite as much in this department, as the reason i know a lot about the batteries is quite frankly lipos scared the crap out of me so i wanted to know everything i could about them before starting to use them.

What i've seen posted in the past is that through adapters you will probably have power loss no matter how good the connection may be, so most everyone solders on the new connector.

Great thanks. I will solder the connector then just to be safe.

[brentm3]

Soldering that connector can be a real pain, btw. If you're not familiar with the technique, watch a few youtubes on it first. I soldered some ******* batteries where the wire was so thick, it had to be shaped almost perfectly round and centered on the lead in order to fit in the connector.

Following up on what Zero is saying, some may try to tell you a 250A battery will hold better voltage than a 125A battery under a heavy load. I have seen plenty of data suggesting this is more a function of battery quality than amps. There are plenty of charts showing lower amp packs maintaining voltage under load better than much higher amp packs, as well as charts showing exactly opposite. Just check the reviews on the pack you're looking at. I've had my lowly ******* pack alongside some pretty high end, high amp stuff, and found no difference on a stock Velineon.

[asheck]

Regardless of what some people think, when comparing accurately rated battery, you will see an increase in performance from a higher amp rated battery. Even if the amperage supplied is much higher then your motor will draw. There is no evidence showing anything otherwise.
Here is a graph at 35amps, and look at the difference's in voltages in batteries that supply more then 100 amps.
http://pic20.picturetrail.com/VOL1338/10348139/19776559/394202348.jpg
At 70 amps it becomes more pronounced.
http://pic20.picturetrail.com/VOL1338/10348139/19776559/394202345.jpg

However, ratings vary much between manufacturers, so the quality of the battery, and who is doing the rating must be taken into account.

[zerolatency79]

There is no evidence showing anything otherwise.

Evidence?

Exibit A - A background in electrical engineering, but that doesn't mean much to you so...

Exibit B - A shootout lipo test from a well known public source...

http://www.bigsquidrc.com/pictures/lipo_shootout/2010/thumb/load_test.jpg

Ace - 5000 40c (200a)
Venom - 5000 20c (100a)
Checkpoint - 5000 40c (200a)
Empire(Hyperion) - 5000 30c (150a)
***** - 5000 30c (150a)
JGB - 5200 35c (182a)
Common Sense - 5000 40c (200a)
winforce - 5000 30c (150a)

My point being that it has more to do with pack quality than anything to do with that surplus amperage you seem to enjoy stockpiling.
By saying keeping voltage under load is what makes the pack your basically telling everyone out there that ***** = hyperion, and i bet you don't want to do that do you? (both were 7.18v under load)


The defense rests....

[asheck]

You seemed to have missed this,
when comparing accurately rated battery, you will see an increase in performance from a higher amp rated battery. Because I also say
However, ratings vary much between manufacturers, so the quality of the battery, and who is doing the rating must be taken into account. Thank you for posting the proof of this.

However if you look at the graphs I posted, using SPC batts for reference, same manufacurer, same rating system, you can clearly see that even under a 35amp load, the battery with the highest amp rating performs better. This is undisputable, as the battery manufacturer himself will detest to. :)
So unless you can show me where a battery that is rated, by the same people, at 100amps, that performs as good as a battery that is rated at 200amps, in a relevant situation, then this statement,
Regardless of what some people think, when comparing accurately rated battery, you will see an increase in performance from a higher amp rated battery. Even if the amperage supplied is much higher then your motor will draw. There is no evidence showing anything otherwise.
is true.

Now I don't want to get into which battery is best, and I know that you don't need an overwhelming amount of amps, generally 50 is enough, but you will feel a difference going to a higher rated battery, regardless of your motor's draw.

[brentm3]

http://i198.photobucket.com/albums/aa176/brentm3_photos/IMAG0716-1.jpg

Hey Zero, check this out! I got myself a 490 amp pack, wait 'till I get this thing to the track, my stock Velineon will really haul now.

Once I saw the troll pop up, I knew where this thread was going. Of course, your chart didn't contain any accurately rated battery...but aschecks did. Silly Venom, intentionally underrating their batteries to keep those pesky customers away...or wait, was ascheck implying that Hyperion, Checkpoint, and the rest are all liars?

He won't give up, FYI. He may even get someone else in here to play "yes man"...

Attacking other members will get you warning points.
-ksb51rl

[zerolatency79]

@asheck

1 Thunder Power Pro Race 5000 40c - 7.13v 200A
2 Thunder Power Sport Race 8000 22c - 7.13v 176A
3 Thunder Power Sport Race 5400 25c - 7.12v 135A

hmmm so i guess this kinda proves your point too.... except 200a vs 176a is no different, and 200a vs 135a is only 1/100v different...(which wouldn't have even shown up on your chart chart).... i wonder what the % error on the meter big squid used was...

[zerolatency79]

http://i198.photobucket.com/albums/aa176/brentm3_photos/IMAG0716-1.jpg

Hey Zero, check this out! I got myself a 490 amp pack, wait 'till I get this thing to the track, my stock Velineon will really haul now.


wow, awesome... i wish i could draw that many amps....

[asheck]

@asheck

1 Thunder Power Pro Race 5000 40c - 7.13v 200A
2 Thunder Power Sport Race 8000 22c - 7.13v 176A
3 Thunder Power Sport Race 5400 25c - 7.12v 135A

hmmm so i guess this kinda proves your point too.... except 200a vs 176a is no different, and 200a vs 135a is only 1/100v different...(which wouldn't have even shown up on your chart chart).... i wonder what the % error on the meter big squid used was... There is so much info missing from this, that a conclusion can not be reached from it. How long was this discharge? At what point did they take this reading, what was the amperage, ECT. If you can share all that, please do. The BIG Squid battery shootout's do not hold all answers :) Zero, I hope you can discuss this as we are supposed to, I really think having this correct information is important for those who want to know how this stuff works.

[Geodude85]

Regardless of what some people think, when comparing accurately rated battery, you will see an increase in performance from a higher amp rated battery. Even if the amperage supplied is much higher then your motor will draw. There is no evidence showing anything otherwise.
Here is a graph at 35amps, and look at the difference's in voltages in batteries that supply more then 100 amps.
http://pic20.picturetrail.com/VOL1338/10348139/19776559/394202348.jpg
At 70 amps it becomes more pronounced.
http://pic20.picturetrail.com/VOL1338/10348139/19776559/394202345.jpg

However, ratings vary much between manufacturers, so the quality of the battery, and who is doing the rating must be taken into account.

I've been looking over your graphs. Isn't the mah rating the cause for the lower voltage in the Blue lipos and SPC lipo? The Blue lipos and SPC lipo are rated at 5000 mah each, and the other SPC lipo and SMC lipo are rated at 6000 mah and 5400 mah. If you're measuring how much voltage is left in the packs when you're discharging them at an equal amp rate over a set amount of time, then it would make sense that the higher rated mah batteries would have more voltage left at any given amount of time, because it would take longer for their voltage to drop. I don't see what the C rating has much to do with it.

A better way to demonstrate how the C rating affects a battery's voltage is to compare two equally brand name lipos (to avoid as many variables as possible) with equal mah ratings, but different C ratings, ie a ******* 5000 mah 20 C battery, and a ******* 5000 mah 40 C battery. You could do the same test as above in your graph, and see which battery has the higher voltage over the length of their runs (which should be equal, in theory). If the higher rated C battery has more voltage throughout the entire run, then you'd be correct.

Edit: Another thing I noticed is that while drawing 35 amps, the batteries last roughly 9-10 minutes. During a regular bashing session for me, the batteries last roughly 20-25 minutes. Does this mean I'm drawing significantly less amps than 35 amps throughout the entire run? If that's the case, then the lesser the amps that you're drawing from a pack, the less difference in performance there seems to be. In other words, if you're just bashing and not racing, then you won't notice a large difference.

[asheck]

Isn't the mah rating the cause for the lower voltage in the Blue lipos and SPC lipo? Not really, the mah does not play into the voltage, other then the amp rating ( capacity X c rating/ 1000= amp rating), until the very end of the discharge. The pack that holds the highest voltage is the 5400mah battery, until it dumps, and the 6000mah overtakes it. Which is where the capacity comes into it.


A better way to demonstrate how the C rating affects a battery's voltage is to compare two equally brand name lipos (to avoid as many variables as possible) with equal mah ratings, but different C ratings, ie a ******* 5000 mah 20 C battery, and a ******* 5000 mah 40 C battery. I agree. However, this is the best I can provide at the moment that is relevant to this discussion. I intend to do testing on which performs better, getting your amps from C rating or capacity, if I can find a battery that fits here, I will go ahead and test this also.



Another thing I noticed is that while drawing 35 amps, the batteries last roughly 9-10 minutes. During a regular bashing session for me, the batteries last roughly 20-25 minutes. Does this mean I'm drawing significantly less amps than 35 amps throughout the entire run? Yes. Most people will only average 10-15 amps constant.
If that's the case, then the lesser the amps that you're drawing from a pack, the less difference in performance there seems to be. In other words, if you're just bashing and not racing, then you won't notice a large difference. This is true. The lower you are geared, the less noticeable it will be. Going from a 5000mah 20c pack, to a 40c pack if you are geared for 25mph on 2s would be hard to tell a difference. But gear for 50mph and you feel the difference, especially in punch. You could also expect to get more cycles out of a higher amp battery, given identical amp draws. IOW put both the 20c and 40c packs through 100 cycles at a 50amp discharge, and you can expect the 40c battery to be holding more capacity afterwards.


I'm not trying to convince anyone that they need big amp #'s, I'm just saying that there is a difference, it is noticeable, and it can be beneficial to run a higher amp battery.

[zerolatency79]

There is so much info missing from this, that a conclusion can not be reached from it. How long was this discharge? At what point did they take this reading, what was the amperage, ECT. If you can share all that, please do. The BIG Squid battery shootout's do not hold all answers :) Zero, I hope you can discuss this as we are supposed to, I really think having this correct information is important for those who want to know how this stuff works.

Packs were fully charged at 1C, then discharged at 30 amps continuous to a cut off point of 6.0 total volts by a Competition Electronics Turbo 35. We chose 30 amps because it’s a heavy enough load to create problems in poor packs, and it’s also relatively close to what many drivers will pull on a consistent basis when using brushless motors.

Doesn't tell me at what time interval but i would be more than willing to assume the readings were taken at the same amount of time on each pack.

[zerolatency79]

I would also like to make the point as to the effect your so called higher amp battery may have on a vehicle. When was the last time you drove at 70% (70amps for my purposes) for 9 straight minutes, if you could do that, you and your vehicle are going to be ..... miles apart... I'm guessing probably out of radio range...

The reason i point this out is because your not putting into account battery rebound. When you disconnect the load from the battery voltage quickly rebounds so even if your theory was true you would stab the throttle and the voltage would begin to drop, and according to your graph somewhere between 5 and 10 seconds later the voltage between the batteries begins to separate from one another. 5-10 seconds with a vehicle geared for 25mph which you claim it would be unnoticeable at anyway and you've gone between 183 - 366 ft. My track nor is anywhere i drive give me 366 ft. So once i go a significantly shorter distance than that i would be off the throttle and the cells would be rebounding or under a significantly lighter load.

[Jakey]

... but you will feel a difference going to a higher rated battery, regardless of your motor's draw.
This is undeniably true!

[asheck]

http://www.bigsquidrc.com/lipo-battery-shootout-3-4s-edition/lipo-shootout-3-voltage-under-load-test/ This does a better job showing and describing things, and has graphs. But would like to qoute the article that Zero has been quoting.
So what does this test show? In short, better batteries will give you higher voltage (thus making your car faster) under load. I believe that the graphs I have posted clearly shows that the higher amp rated battery does hold a better voltage under load
Doesn't tell me at what time interval but i would be more than willing to assume the readings were taken at the same amount of time on each pack.It appears like they just average the pack, as here is their graph for the 4s's http://www.bigsquidrc.com/pictures/lipo_shootout/4s_lipo/full/VenVsTurn.jpg Much harder to draw a conclusion from not having the graphs on the others, for us.


The reason i point this out is because your not putting into account battery rebound. When you disconnect the load from the battery voltage quickly rebounds so even if your theory was true you would stab the throttle and the voltage would begin to drop, and according to your graph somewhere between 5 and 10 seconds later the voltage between the batteries begins to separate from one another. 5-10 seconds with a vehicle geared for 25mph which you claim it would be unnoticeable at anyway and you've gone between 183 - 366 ft. My track nor is anywhere i drive give me 366 ft. So once i go a significantly shorter distance than that i would be off the throttle and the cells would be rebounding or under a significantly lighter load. Yes, but you must also take into account the fact that your battery does not always rebound to 8.4 volts. Each time the rebound get's less and less. So each time the voltage get's lower. A constant amp load does a good job of representing the way a pack will perform. Here's an example of what a graphed eagletree run looks like, even though in reality there in a bunch of spikes, there is still a continous voltage drop. Though this is a test type scenario. http://www.rc-monster.com/forum/showthread.php?t=26620&highlight=datalogger

These things are pretty easy on batteries, the differences can be harder to make obvious, especially under the lighter loads. I did testing in my 2wd pede, only I was just geared for 30ish. An older 4000mah 25c battery lipo pulled 30.8mph, the above tested Blue lipo's pulled 34.4 and a 8000mah 20c SPC pack pulled 35.4. So the extra 60 amp rating only netted me 1mph. Though the punch is more then noticable. However Throw Big Joes on a E-revo, Gear for about 70mph on 4s, and the differences become huge. While all my batteries passed the test, the results varied from my 4000mah 25c batteries pulling 47mph, to my SMC 9000mah 28c packs pulling 62mph . The above listed Blue's pull 52, and the SPC 8000's pull 59 .


This is undeniably true!Apparently not :) But still my main point .

[zerolatency79]

This is undeniably true!

thanks for joining in yes man, we missed you.... your scientific proof is invaluable for this argument, glad someone finally jumped in and played asheck's wingman though, i think he was starting to get lonely as the only one arguing that all of my data is invalid...




http://www.bigsquidrc.com/lipo-battery-shootout-3-4s-edition/lipo-shootout-3-voltage-under-load-test/ This does a better job showing and describing things, and has graphs. But would like to qoute the article that Zero has been quoting. I believe that the graphs I have posted clearly shows that the higher amp rated battery does hold a better voltage under loadIt appears like they just average the pack, as here is their graph for the 4s's http://www.bigsquidrc.com/pictures/lipo_shootout/4s_lipo/full/VenVsTurn.jpg Much harder to draw a conclusion from not having the graphs on the others, for us.

Thanks for finding that, i've been looking for it. It shows my point exactly. If you look at the graph they all stay within a relatively close range until they reach the drop off point for a given battery. If you look closely the team checkpoint and the thunder power stay straight in line with each other despite a 30c (189A vs 344A) rating difference between them.... i know you're going to drop the different manufacturer card and i really don't care, i've found 3 data sets although from the same source they all prove my point, you have one data set that covers only two batteries to prove yours. I agree that all manufacturers may not be completely accurate in their ratings but are you going to claim that team checkpoint is going to under rate their battery by 155A or would you like to bash thunder power and say that the 344A rating they have listed is nearly double what it should be?



Yes, but you must also take into account the fact that your battery does not always rebound to 8.4 volts. Each time the rebound get's less and less. So each time the voltage get's lower. A constant amp load does a good job of representing the way a pack will perform. Here's an example of what a graphed eagletree run looks like, even though in reality there in a bunch of spikes, there is still a continous voltage drop. Though this is a test type scenario. http://www.rc-monster.com/forum/showthread.php?t=26620&highlight=datalogger.

Agreed, the packs will not always rebound to max voltage. If they rebounded to 8.4 the pack would never die, and we'd have a battery that we could put in 1/1 scale cars all around the world and we could all drive to work for free... But both packs will rebound and start a similar graph pattern starting at a lower but equal voltage.




These things are pretty easy on batteries, the differences can be harder to make obvious, especially under the lighter loads. I did testing in my 2wd pede, only I was just geared for 30ish. An older 4000mah 25c battery lipo pulled 30.8mph, the above tested Blue lipo's pulled 34.4 and a 8000mah 20c SPC pack pulled 35.4. So the extra 60 amp rating only netted me 1mph. Though the punch is more then noticable. However Throw Big Joes on a E-revo, Gear for about 70mph on 4s, and the differences become huge. While all my batteries passed the test, the results varied from my 4000mah 25c batteries pulling 47mph, to my SMC 9000mah 28c packs pulling 62mph . The above listed Blue's pull 52, and the SPC 8000's pull 59 .

Sorry but your testing doesn't produce any sort of valid data. Your batteries are not the same manufacturer, or of the same age and based on the fact you are doing a speed test not a bench test you also have to consider pack weight (which would be near impossible).... too many variables unable to account for.


This isn't even worth arguing anymore. I gave sound advice for purchasing a pack, the data i have found supports my theory and your data (although a rather small set) supports your theory. The OP wanted recommendations on buying a new pack, not your theory which only if true would result in squeezing .01v out of a pack on an unrealistic bench test. I'm sorry that your life's mantra doesn't hold true but bigger isn't always better.

[Jakey]

thanks for joining in yes man, we missed you.... your scientific proof is invaluable for this argument, glad someone finally jumped in and played asheck's wingman though, i think he was starting to get lonely as the only one arguing that all of my data is invalid....
Very rude!

This isn't even worth arguing anymore.
That is the only correct statement you have made in this entire thread.

[zerolatency79]

Very rude!

so was joining into a thread that had some intelligent conversation with a 4 word response that provided absolutely nothing.