Charging with parrallel connector?

[dr.bjm]

Can I charge two ***** ********* 2s 2200 lipos at the same time if I use the traxxas parallel connector that I use to run the two *****'s?

[AcadDude]

Well you can but balancing is tricky.

[dpacza]

You should never charge lipo batteries in parallel. Charging lipo in parallel can result in you over charging one or several cells. If you want to charge more than one lipo you must always charge in series with a balancer or you risk ruining your batteries.

[lanek99]

You should never charge lipo batteries in parallel. Charging lipo in parallel can result in you over charging one or several cells. If you want to charge more than one lipo you must always charge in series with a balancer or you risk ruining your batteries.

wrong... charging in parallel is in fact very safe, maybe even safer than series, just make sure your cells are within around 30% of each other capacity wise.

I can easily charge 6x 2650 4s batteries in parallel. I also balance the batteries in parallel. It has never once failed and no matter how many batts I charge and balance at once they always come out perfectly balanced.

If you want further proof in regards to safe parallel charging I would recommend you head over to rcgroups.com and start reading

[lanek99]

Well you can but balancing is tricky.

I should also say that balancing is not tricky at all. way easier than setting up harness to balance in series.

[Hughes500Bob]

I sell parallel and series tap harnesses and power harnesses. Charging and balancing in parallel is easier like lanek99 said. There is no way to hook up wrong in parallel ..... just double the amps and leave the voltage the same as one lipo.

Series is also easy with the right harness. If you hook mine up wrong ...it just won't balance ...it will not short anything. Mine are color coded to make hook-up easy. In series your charge voltage is # of cells x 4.2v and keep the amps the same as one lipo.

All cells in either case need to be the same capacity and near the same discharge voltage. If not you just charge the lower lipo until it gets to the higher lipo then stop and reset to charge together.

Charging two lipos and using available unused charger wattage saves time. If you run in series or parallel .... why not use the same power harness to charge both lipos with matching tap adapter????

http://rcsales.shutterfly.com

[lanek99]

thats true about the series charging being safe also, as long as you have the balance adatper setup right. you can see an example on briang's website. I just know a lot of people out there are saying parallel charging is a no no when in fact it works very well. There is nothing wrong with charging in series, I have adapters laying around for that purpose, but imo when charging more than two batts of the same type constructing a parallel harness for this is much easier. If your new into the lipo game and dont want to fry anything go with parallel or pick up one of bob's series harnesses.

[dpacza]

I am not aware of any manufactures that will support charging lipo in parallel, but prove me wrong.

[lanek99]

Are there manufactures that explicitly state not to parallel charge their batteries. Either way it is safe, and I welcome you to provide data showing that parallel charging is damaging or harmful.

….and no, you do not run the risk of overcharging a cell

[Hughes500Bob]

I can only say that I have been parallel charging for years. I have seen 11 being parallel charged at one time. The most I have done on a regular basis is 4 2S 5000 mAh in parallel at 20 amps. I sell about a 50/50 mix of parallel and series tap adapters.

Technically .... Lipoly and lead acid are essentially current-limited, constant-potential charge systems; they charge to a specific cut off voltage while the current tapers off as they approach that voltage. Two packs of equal numbers of cells in parallel will by definition have the same voltage under charge and discharge. Each will accept current as required to attain the cutoff voltage. If packs are in a similar state of discharge I actually accept no more than .3 volts as a cell difference. It usually takes about 20 seconds for them to self-equalize and since they are partially discharged the current flow to equalize is actually very low. I encourage .1 volt difference to be the voltage skew for my customers. I have actually parallel charged packs of different capacities (same number of cells!!) and they charge just fine as all cells aproach 4.2 volts. I will borrow anothers pic to show this ..... notice how the vessels have different volumes but still fill to the same level:


Remeber this does not apply to NiMH or NiCD as they should NEVER be charged in parallel. I can point you to numerous parallel lipo charging threads in other rc forums if you still need more proof that this is safe.

If lipos can be run in parallel .... why can't they be charged in parallel? Constant current/constant voltage charging of lipos is what makes this work. They are charged to a specific voltage and the charge is terminated.

[lanek99]

thats the pic I was going to use in the event I had to explain myself. Julez over at rcgoups mentioned he tested a drained pack with a fully charged one and the initial current between the two was 10amps then within a minute was less than 2a. Though his testing was with A123 cells. Though I dont do this on a regular basis, I have chaged packs together that were within 50% capacity of one another. I have 6 lipos I use and run 2 at a time in parallel. When the pack are out of the car I keep them rubber banded together so I always know which pair are on par with one another.

[Hughes500Bob]

Like minds think alike! Lot's of good stuff over at rcgroups to back us up!! "Everydayflyer" is a good forum friend of mine!

[lanek99]

lol. there is an extreme amount of information over there, especially if someone wants to know more about batteries and charging. That’s kind of how I picked the icharger 208b as my charger. There is a 300 page discussion for the icharger, and the company frequents it to help with problems as well as providing regular firmware updates. I remember an instance when they first started selling the 208b and someone got one with the 1010+ casing, but the 208b internals. Junsi (I believe this is the company’s name) had the guy pm him his address and sent the new casing free of charge. I thought that was pretty good service, and they listen to their customers when releasing firmware updates which is also great service.

….but back to the point, it is an overall great forum and any newb or pro would benefit from the info found there.