Quote:
Originally Posted by Torgus
Quote:
Originally Posted by Biginboca
If the car ever won’t start there’s a button you can hit on a wireless remote (there’s also a button on the battery itself) and it will give you enough juice for one start.
I have had the battery for a year now and never needed to use this feature but it’s nice to know it’s there.
So in theory if your car ever didn’t crank because you left something on and the battery was dead, you would just hit a button on the remote right from the drivers seat and it would start.
|
Neat. So basically they have a built in discharge level that can't be exceeded. Press the button internal contactor closes and allows you to draw the from battery again. Or something like that, multiple ways to do it I imagine. Neat feature. Probably also saves you from killing the battery via deep discharge and saves them on warranty claims. If you never allow the battery to go below say, 25% discharge, unlikely you will have to pay out warranty claims when a customer kills the battery themselves. |
Actually all good Li batteries have a built in BMS (battery management system) that monitors at least voltage and temperatures.
Once the battery drops below a set voltage threshold the BMS will disconnect the battery from any loads. Usually the set point is something like 10 volts or about 99 percent depleted. At some voltage below this the battery becomes unstable and "bad" things can happen. The industry likes to phrase these things as "thermal events".
The BMS system also manages the recharge cycles insuring that each bank of cells is recharged evenly. Uneven charge levels will dramatically shorten the life of the battery.
I like the idea of a higher cut off voltage and the ability to press a button to pull up reserve capacity but in-practice it scares me. A reasonable cut off voltage would be closer to 12 volts or higher and I sure to hell don't won't my battery cutting off at a traffic light and night on a raining day.
I've done a lot of research on these batteries and we've started using a 100 amp product as standard equipment so I'm spending an easy 500k a year on them. So far they are great the ability to absorb current and quickly supply heavy loads is phenomenal. Sorry these are heavy duty and not available for resale.
Beware, there are lots of cheap Li batteries on the market with poorly designed or even no BMS system at all. Another important topic never discussed at the auto parts store is cell balancing, when building a Li battery all of the individual cells must be matched with cells with similar storage capacity. This is quality control during the assembly stage.