jdieringer
New Member
- Joined
- Feb 18, 2021
- Messages
- 6
Hi all, found this great community through watching Will on the youtube channel. My use case is a little different from others so I am curious thoughts as to is a BMS needed. I fly R/C airplanes and used to charge my batteries with my Prius, it was nice as it had 70A of 12V on tap when the ignition was on. Being a hybrid, the ICE would only pop on every once in a while.
I now have a minivan. I am not really keen on getting a portable inverter generator but would rather like to build a 4s 280Ah pack to take on the road. My math says I will get 12 or so charges of my flight packs which is plenty for a weekend of flying at contests. I do not intend to connect the battery to my vehicle, but would rather charge and store offline. I am battling if I need a BMS. I have the following:
iCharger 4010Duo which in synchronous mode can balance charge the LiFePO4 4s 280Ah battery at 70A with 2.4A sink current per balance tap. I power this with a Meanwell 1000W 24V DC power supply so should be about right. I also have an icharger 308 Duo which can do the same but 50A synchronous.
The iCharger can charge with or without balance lead so I can use a BMS. 99% of the time, I will top balance the pack, go to a contest, charge flight batteries to maybe 20-50% of the big battery and then come home. If I am going to be putting it away for a while, I may storage charge it to 50%. The chargers do have capability to discharge packs back into the source (regenerative discharge) but that will not be balance assisted without a BMS. The next charge cycle will be balance charged though.
So I see 2 scenarios.
1: Use a BMS and use my charger as a DC DC charger. The BMS would then continuously balance my big battery and also handle balancing of my regenerative discharge cycles.
2: Forget the BMS, it won't get that far out of sync in a couple cycles and rely on my charger to top balance.
I will also probably install a shunt to track the charge state.
Thanks!
I now have a minivan. I am not really keen on getting a portable inverter generator but would rather like to build a 4s 280Ah pack to take on the road. My math says I will get 12 or so charges of my flight packs which is plenty for a weekend of flying at contests. I do not intend to connect the battery to my vehicle, but would rather charge and store offline. I am battling if I need a BMS. I have the following:
iCharger 4010Duo which in synchronous mode can balance charge the LiFePO4 4s 280Ah battery at 70A with 2.4A sink current per balance tap. I power this with a Meanwell 1000W 24V DC power supply so should be about right. I also have an icharger 308 Duo which can do the same but 50A synchronous.
The iCharger can charge with or without balance lead so I can use a BMS. 99% of the time, I will top balance the pack, go to a contest, charge flight batteries to maybe 20-50% of the big battery and then come home. If I am going to be putting it away for a while, I may storage charge it to 50%. The chargers do have capability to discharge packs back into the source (regenerative discharge) but that will not be balance assisted without a BMS. The next charge cycle will be balance charged though.
So I see 2 scenarios.
1: Use a BMS and use my charger as a DC DC charger. The BMS would then continuously balance my big battery and also handle balancing of my regenerative discharge cycles.
2: Forget the BMS, it won't get that far out of sync in a couple cycles and rely on my charger to top balance.
I will also probably install a shunt to track the charge state.
Thanks!