Mic the Vegan YT
New Member
- Joined
- Feb 14, 2020
- Messages
- 10
Hey guys,
I am new to the DIY Lifepo4 topic but I am quite sure I want to use them for a 1,400-1,800 watt system for my tiny house on wheels. My problem is the tiny house is going to use a 9,000 BTU mini split and the run time / watt hours per day of this is almost impossible to estimate accurately (similarly sized AC systems burn around 2,600 watts a day but who knows: https://homeguides.sfgate.com/much-cost-run-portable-air-conditioner-102489.html). That's 216 amp hours at 12 volts if my math is right. We have grid as a back up if we run out of power.
So my question is, would it be a bad idea to buy a batch of about 400 ah worth of 12V batteries now and then if I need another 400 ah buy it later if I need it? I understand that these batteries become unbalanced through different use scenarios due to charge cycles. But would 30-40 charge cycles out of thousands really ruin it? I could even run the equivalent amount of charge cycles for the second batch of batteries with the first batch to give them the same amount of wear. The temperature will be constant. Has anyone thought about this? I didn't see it addressed at first glance so sorry if it was.
P.S. If anyone is concerned about such a high wattage 12V system my plan is to use 3 parallel 40+ amp mppt controllers. I would go 24V but I already have a 12V inverter and don't want that 12-24 DC converter energy loss.
Thanks,
Mike / Mic
I am new to the DIY Lifepo4 topic but I am quite sure I want to use them for a 1,400-1,800 watt system for my tiny house on wheels. My problem is the tiny house is going to use a 9,000 BTU mini split and the run time / watt hours per day of this is almost impossible to estimate accurately (similarly sized AC systems burn around 2,600 watts a day but who knows: https://homeguides.sfgate.com/much-cost-run-portable-air-conditioner-102489.html). That's 216 amp hours at 12 volts if my math is right. We have grid as a back up if we run out of power.
So my question is, would it be a bad idea to buy a batch of about 400 ah worth of 12V batteries now and then if I need another 400 ah buy it later if I need it? I understand that these batteries become unbalanced through different use scenarios due to charge cycles. But would 30-40 charge cycles out of thousands really ruin it? I could even run the equivalent amount of charge cycles for the second batch of batteries with the first batch to give them the same amount of wear. The temperature will be constant. Has anyone thought about this? I didn't see it addressed at first glance so sorry if it was.
P.S. If anyone is concerned about such a high wattage 12V system my plan is to use 3 parallel 40+ amp mppt controllers. I would go 24V but I already have a 12V inverter and don't want that 12-24 DC converter energy loss.
Thanks,
Mike / Mic