As a battery ages the mAh of the battery degrades, as the mAh degrades so does the batteries c rating (amp limit). So down the road, your 20A battery may only be a 10A battery.
Rest batteries after charging:
One commonly-reported factor in almost all the incidents we hear of where batteries failed violently while in use is that they were taken directly off the charger and then used immediately, at which point they failed.
Because of this, we think it may be a good idea to rest batteries after charging them. This advice will not be found in the usual 'reference bibles' on batteries, but we see more and different reports than others. Therefore we now advise:
Do not use batteries directly after charging them. Use a battery or batteries you previously charged, and that have rested for several hours. This is especially important if using a stacked pair for higher voltage, as statistically the risk is far higher.
The benefit to resting is increased battery lifespan & minimize the chance of venting. The better you treat your batteries the better they treat you. I use three batteries in rotation: one in my mod, one on my charger, and one charged and resting.
IMHO, its better to recharge a battery before it drains dead. In other words, recharge it at 3.6 volts instead of waiting until its 3.4 volts or lower. "Topping a battery off" is better than draining it dead. Draining a battery dead is hard on battery life.
