jvbutter01
New Member
- Joined
- Aug 20, 2020
- Messages
- 208
Trying to replace my current FLA batteries with LifePo. I have already 8 cells of 280ah. Trying to figure out if I series them to make 24v @280ah, will this be enough? Its winter time, and the RV has been put to bed for few months. I cannot use my Victron 712 to check the usage. I also don't want to wait until next year to finish the battery bank. I will NOT have any solar for recharge at this point. Only small generator. The idea is to run off batteries for 2-3 days before recharge.
Considering I will need (from estimates below) a 3k/watt inverter to change 24v to 110v for RV panel usage. Inverter will have a 150a draw at max load. Max usage is 7042watts per day estimated.
24v @ 150a = 3600watt. this is 1 hour and then the battery is dead. Obviously it wont run full amps for 1 hour as shown below. Bottom is 7042 usage for a day. Does this mean I will need parallel string of 280a to supply 1 days worth of 7042Watt? This doesn't seem right, but its the math I have tried to figure out.
Looking at the Battery FAQ
How do I convert my Watt Power needs into a number of battery Ah?
You need 6 kWh/day and you want 3 days autonomy: 6000 x 3 = 18,000 Wh
My math but be off somewhere. At this point, i need 3 strings of 24v 280ah.
120v
Item watts usage watt/usage
coffee pot 1500w 30min/d 750
microwave 1600w 5min/d 500
12v
vent fan 200w 24hr/d 4800
radio 25w 8hr/d 200
heater fan 132w 6hr/d ` 792
int lights ???w
12v H2O pump ???w
fridge - propane
total 7042
Considering I will need (from estimates below) a 3k/watt inverter to change 24v to 110v for RV panel usage. Inverter will have a 150a draw at max load. Max usage is 7042watts per day estimated.
24v @ 150a = 3600watt. this is 1 hour and then the battery is dead. Obviously it wont run full amps for 1 hour as shown below. Bottom is 7042 usage for a day. Does this mean I will need parallel string of 280a to supply 1 days worth of 7042Watt? This doesn't seem right, but its the math I have tried to figure out.
Looking at the Battery FAQ
How do I convert my Watt Power needs into a number of battery Ah?
You need 6 kWh/day and you want 3 days autonomy: 6000 x 3 = 18,000 Wh
My math but be off somewhere. At this point, i need 3 strings of 24v 280ah.
120v
Item watts usage watt/usage
coffee pot 1500w 30min/d 750
microwave 1600w 5min/d 500
12v
vent fan 200w 24hr/d 4800
radio 25w 8hr/d 200
heater fan 132w 6hr/d ` 792
int lights ???w
12v H2O pump ???w
fridge - propane
total 7042