Question for all the electrical gurus about battery packs
Hey I have a jato3.3 and was curious about the batteries. I have a specktrum dx3.0 transmitter and a 1500mah 5 cell pack for the receiver. I read in the manual that the specktrum displays "low batt" when the voltage drops below 9V. Since the spektrum holds 8 AA's the full charge should be 12 V. That means that at 9V, each cell contains 1.2V. Specktrum recommends that the batteries are replaced or charged when the voltage is below that threshold. From what I read about ni-mh batteries, they dont have memory but should occasionally be drained to 20% or less to exercise the cell's electrons. If the spektrum indicates low batt at 9V, theyre expecting you to recharge when each cell is at 75%? Although that scenario is understandable since they only "recommend" it (and i can continue to run the batteries until they are further drained), what I don't get is the receiver's failsafe. I believe the receiver gets thrown into the failsafe mode when the battery pack is below 5 to 6 volts. That also means that each cell is barely drained below 70%. Does anyone know of any good ways of keeping the battery lives healthy? I know there are fancy battery dis-chargers out there but they are very pricey. I also know that just leaving the receiver on when not in use can drain the battery pack too low and can damage the cells.
Also, it is recommended that the batteries are charged at the rate they are approximately used. For example, the nicad battery in the ez starter should be charged at 1C of the capacity (typically around 1.5 A). Does anyone know of any recommendations of charge rates for 5 cell ni-mh packs for the receiver? What about for the transmitter? My best guess would be that they should both be charged at .5A or less but im sure theres people out there who know better.
Anyways, i dont mean to come off as a crazy guy worried about the batteries on the car and the receiver. I just wanted to learn the better habits of maintaining the battery packs so that I would ultimately spend less time and money on batteries and more fun on nitro. Thanks in advanced guys, greatly appreciate the help.
I think your DX3 show "low batt" means the 8 AA battery on the transmitter. not the RX nor EZ-start battery pack.
yes thats correct, however the receiver goes into fail-safe mode when the receiver battery pack's voltage drops below the set threshold
i have a dxr3 and you can go into the settings and set the voltage limit to what ever you want, i have not used the dx3 so i do not know if you can set it. the dxr3 also only takes 4AA's and i have my voltage set at 3.9v