Battery recommendations for 1500W inverter
Does anyone have recommendations for a 12V battery setup that can power a 1500W inverter? The background: my travel trailer is currently powered by two 6V golf cart batteries (Duracell SLIGC110 215...
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You can tell how the batts are with an hydrometer. You still need to beef up the wiring.
My 2000w inverter has two pos and two neg wires all 3 ft #4 AWG cu. If you just have one each of 5 ft #4, that is not enough in real life, despite the ampacity tables.
With that and a bit more wiring for the Trimetric shunt I can pull 120 amps from four batts and get a voltage drop around 0.7v With just two #4s you will see over 1 volt drop. Your idea of 1/4 volt just doesn't happen that way. You can play with battery type and AH of bank, but you still need short fat wiring inverter to bank.
I ran that with two 12v T-1275s rated 150AH each (actual was 130 each at the age they were then) no problem. Two 6s were a problem unless over 75% SOC. I did it with three 12v 27s too, and got by.
Now I have the four 3ft #4s plus some more wire to a bank of 450AH of deep cycle 12v AGMs (two 100s and a 250) and I am getting a 0.9 volt drop with my wiring zoo, which I can live with. Good "bounce back" on voltage when the load is reduced.
Try two 5ft #1 AWG instead and you will be amazed at the difference, plus make sure the two 6s are fully recharged and do not "collapse" in voltage under load.
A 1 volt drop means you need to start with the batts resting at least 12.2v (just over 50% SOC) so they stay over 11.2v at first and then above 11 while the load is running. (inverter alarm)
You can juggle with wiring and battery and load amount and load run time in whatever combo to achieve that.
The target of being able to do that with the batts at 50% is so you can still make toast with your electric toaster when the batts are low and it is still early before gen hours start later that day.
You will be recharging anyway that day because you want to only let the batts get down to 50% before recharging them. So that all works out for how low the batts will be in the worst case you need to set up for
My 2000w inverter has two pos and two neg wires all 3 ft #4 AWG cu. If you just have one each of 5 ft #4, that is not enough in real life, despite the ampacity tables.
With that and a bit more wiring for the Trimetric shunt I can pull 120 amps from four batts and get a voltage drop around 0.7v With just two #4s you will see over 1 volt drop. Your idea of 1/4 volt just doesn't happen that way. You can play with battery type and AH of bank, but you still need short fat wiring inverter to bank.
I ran that with two 12v T-1275s rated 150AH each (actual was 130 each at the age they were then) no problem. Two 6s were a problem unless over 75% SOC. I did it with three 12v 27s too, and got by.
Now I have the four 3ft #4s plus some more wire to a bank of 450AH of deep cycle 12v AGMs (two 100s and a 250) and I am getting a 0.9 volt drop with my wiring zoo, which I can live with. Good "bounce back" on voltage when the load is reduced.
Try two 5ft #1 AWG instead and you will be amazed at the difference, plus make sure the two 6s are fully recharged and do not "collapse" in voltage under load.
A 1 volt drop means you need to start with the batts resting at least 12.2v (just over 50% SOC) so they stay over 11.2v at first and then above 11 while the load is running. (inverter alarm)
You can juggle with wiring and battery and load amount and load run time in whatever combo to achieve that.
The target of being able to do that with the batts at 50% is so you can still make toast with your electric toaster when the batts are low and it is still early before gen hours start later that day.
You will be recharging anyway that day because you want to only let the batts get down to 50% before recharging them. So that all works out for how low the batts will be in the worst case you need to set up for
