BeerBrewer
New Member
- Joined
- May 14, 2020
- Messages
- 23
I'm planning upon adding solar power to my Travel Trailer in the next year of so and I'd like do it in stages. The plan right now includes at least 200 ah battery of power (at 12V), four 100-150 Watt solar panels, a new converter for lithium cells, MPPT solar controller and a 2000 watt pure sign wave inverter. My first step is to replace the lead acid battery with a DIY 12v or 24v Lithium LiFePo4 battery. I've seen several sellers on Alibaba/Aliexpress selling brand new 3.2v 100ah LiFePo4 cells for around $75-$80, making a DIY battery A LOT cheaper than a Battle Born or Lion 12V battery. I know that I'd need to add a BMS, but I not certain which to choose.
I've read that I need to size the BMS for the maximum discharge rate on the batteries, even if it its for a very short time. So I'm thinking that the max draw will be when my wife uses the hair dryer for 5 minutes or whenever the 2000 inverter is maxed out. I've looked at specs for some 2000 watt PS Inverters and they all claim the max DC power draw is around 198 amps at 12v and 99 amps if I use a 24V volt inverter. So does this mean that if I build two 100ah 12V lithium Batteries in parallel that each battery will need it's own 100 amp BMS or should I build one 200ah battery (using all 8 cells) using one 200 amp BMS?
What about if I convert the travel trailer over to a 24 volt battery system? Should I build two 12v batteries connected in series with each battery having its own 50 amp BMS or is it better to build a single 24V battery using all 8 100ah cells using a single 100 amp BMS?
I'm also having issues finding a BMS with a low temp shot-off. If you folks have a favorite BMS I'd love to hear it.
Thanks
I've read that I need to size the BMS for the maximum discharge rate on the batteries, even if it its for a very short time. So I'm thinking that the max draw will be when my wife uses the hair dryer for 5 minutes or whenever the 2000 inverter is maxed out. I've looked at specs for some 2000 watt PS Inverters and they all claim the max DC power draw is around 198 amps at 12v and 99 amps if I use a 24V volt inverter. So does this mean that if I build two 100ah 12V lithium Batteries in parallel that each battery will need it's own 100 amp BMS or should I build one 200ah battery (using all 8 cells) using one 200 amp BMS?
What about if I convert the travel trailer over to a 24 volt battery system? Should I build two 12v batteries connected in series with each battery having its own 50 amp BMS or is it better to build a single 24V battery using all 8 100ah cells using a single 100 amp BMS?
I'm also having issues finding a BMS with a low temp shot-off. If you folks have a favorite BMS I'd love to hear it.
Thanks