manly
New Member
- Joined
- Jun 23, 2021
- Messages
- 49
Long story short, I recently purchased at 39' Catamaran that came with 10 DragonFly LiFePo4 batteries (essentially BattleBorn but with a different sticker). They are 100 ah each, so that gives me 1,000 Amp-Hours at 12 volts. They were purchased in 2018. I'm planning to capacity test each but haven't yet.
The kicker: before purchasing this boat I had already been putting together a DIY LiFePo4 pack with 280ah Eve Cells. I have 16 cells and am making 4 12V batteries with OverKill Solar BMS's. That gives me 1,120 Amp-Hours at 12 volts.
Together, that's 2,120 amp-hours, which is a lot of battery! The boat only has 960 watts of solar over the dinghy davits. No generator. I'd prefer not to have a generator. For about $3,000 I could add another 1,000 watts of flexible panels (the ones Will recommends) on top our cockpit canvas enclosure. I measured already and that much will easily fit.
Our largest load is the air conditioner off the inverter. We have a 3,000va Victron Quattro inverter.
Scratching my head on how to manage this much power. Options I'm thinking of:
A) Run all loads from one bank and keep the other charged via a DC-DC charger. Then if we run the first bank down too far we can switch to Bank #2 as a backup. This is nice from a redundancy standpoint, but I have a feeling we would hardly ever use Bank #2 so it would just be sitting there doing nothing.
B) Put the whole bank together in parallel, but that is 14 BMS's in parallel! 10 of them 100ah while 4 would be 280ah. Is this even a good idea?
C) Run the inverter off one bank (that stays topped up with a DC-DC charger from the other bank) and all other DC loads from the other bank that would stay topped up from solar.
D) Sell one or the other bank.
E) Use the Dragonfly batteries to convert our 11.5' dinghy to electric? It currently has a 15hp yamaha.
Thoughts?
The kicker: before purchasing this boat I had already been putting together a DIY LiFePo4 pack with 280ah Eve Cells. I have 16 cells and am making 4 12V batteries with OverKill Solar BMS's. That gives me 1,120 Amp-Hours at 12 volts.
Together, that's 2,120 amp-hours, which is a lot of battery! The boat only has 960 watts of solar over the dinghy davits. No generator. I'd prefer not to have a generator. For about $3,000 I could add another 1,000 watts of flexible panels (the ones Will recommends) on top our cockpit canvas enclosure. I measured already and that much will easily fit.
Our largest load is the air conditioner off the inverter. We have a 3,000va Victron Quattro inverter.
Scratching my head on how to manage this much power. Options I'm thinking of:
A) Run all loads from one bank and keep the other charged via a DC-DC charger. Then if we run the first bank down too far we can switch to Bank #2 as a backup. This is nice from a redundancy standpoint, but I have a feeling we would hardly ever use Bank #2 so it would just be sitting there doing nothing.
B) Put the whole bank together in parallel, but that is 14 BMS's in parallel! 10 of them 100ah while 4 would be 280ah. Is this even a good idea?
C) Run the inverter off one bank (that stays topped up with a DC-DC charger from the other bank) and all other DC loads from the other bank that would stay topped up from solar.
D) Sell one or the other bank.
E) Use the Dragonfly batteries to convert our 11.5' dinghy to electric? It currently has a 15hp yamaha.
Thoughts?