EMS changes with Lithium upgrade

[Wazbro]

Back to intended subject of this thread.

No you do not NEED a Power Control System. It is only there so you don't have to pay attention to how much power you use at any given time. The downside is you will trip breakers and need to reset them if you run too much at one time instead of the Power Control System doing that for you. The upside is one less thing that can fail.
Edit I've had a 30 amp trailer for 20 years that never had one. Yes I have tripped the 30 amp breaker on the pedestal twice in those 20 years (not counting times when the breaker was bad).

[PB_NB]

Originally Posted by Pahaska

Believe me, the BMS in my BMW I3 does exactly those things, not only when the HV battery is being charged, but when it is being used in hot or cold conditions. This is true of just about every EV on the road with the exception of the early Nissan Leaf and maybe the smart. Nissan tried to get away with no controls and failed miserably.

I charged in the hot garage yesterday afternoon and the cooling system automatically turned on to cool the HV battery. I normally automatically charge from 11:00 PM to 7:00 AM when the electric rates are the lowest and the temperature low enough that cooling is not needed.

Is that your tow vehicle?

Just kidding, but I have a 2015 i3 and it does a fantastic job of BM. The application in the BMW case is a bit more robust with cooling and heating.

My 250a LifePO4 battery has a BMS but I think it really only throttles the charge current and slows it when you are past 85% SOC. I have watched my input charge amps drop as the SOC nears full. I have a temp sensor as well but it doesn't report much in the way of heat changes and at 14.3V it stops taking anymore charge and the charger output is recorded at zero amps. This is the BMS at work since the charger wants to deliver 55a whenever plugged in.

[Pahaska]

Originally Posted by PB_NB

Is that your tow vehicle?

Just kidding, but I have a 2015 I3 and it does a fantastic job of BM. The application in the BMW case is a bit more robust with cooling and heating.

I bought a certified 2018 I3 Rex 3 month ago. Fantastic car! I go places just to drive it

I wish I could tow it, but I will not use a trailer or dolly to do so. I'll stick with my Fiesta for a toad.

[jimdelane]

unclebob has a point. Comparing EV batteries to RV batteries is apples to oranges. RV batteries are deep cycle whereas EV are high discharge. RV are generally LiFePO4 and EV are nickel-cobalt (NCM) chemistry. LiFePO4 (LFP) manufacured batteries are perfectly suited for RV use. They are safe, have built in BMS and are dropping in price. NCM are those batteries you hear about that explode and catch fire. I would hesitate putting in a EV (NCM) battery into a RV app but would not think twice about installing a LFP battery.