I have an RV which recently had the original propane fridge fail. I replaced it with a "GoWise Power" 1000W pure sine wave inverter and a residential type compressor fridge. I've been having problems with the inverter cutting off when first starting the fridge. Right now the RV is running dual 6V 210Ah GC2 size batteries which are only about 18 months old. There's 300W of solar on the roof and a Victron MPPT charge controller. According to the Victron app, I'm getting a full charge each day.
Measuring the fridge with a kill-a-watt, it draws about 46W when running. Startup is hard to catch, but it seems to be around the 300-450W range for less than 2 seconds. The refresh rate of the kill-a-watt makes it hard to see the exact value, but it's very brief.
After a night with the furnace going, I've occasionally had issues where the inverter hits the low voltage cutoff when the fridge tries to state in the morning. The batteries still have plenty of energy to crank the big generator over, but that early morning voltage droop is irritating the inverter for the 2 seconds the fridge is drawing more power. I have the inverter mounted as close to the batteries as physically possible.
I had a few thoughts on what to do to remedy this:
1. See if there's a way to disable/modify that low voltage cutoff on the inverter. I've seen a thread here to do that on a different model. Given that the batteries are still able to crank the generator over quickly, I don't think I'm lacking in actual capacity; it's just the sag of the lead acid batteries under any sort of load gets them very near that 10V cutoff.
2. Look into some sort of DC-DC boost converter to give the inverter a more stable supply. Finding one that's 80-100A capable seems to be a challenge.
3. Upgrade to lithium batteries. The increased Ah rating is good, but what I'm really after is that flatter voltage curve. The Victron MPPT controller can handle them and I'd pair it with a good BMS. I dont think I'd need much else to complete the upgrade.
Any other suggestions for this setup? Also, is it recommended to leave the batteries and solar connected when the RV is stored, allowing the Victron controller to do its thing? Or is it better to disconnect everything when the RV is not in use to keep the cycle count low?
Measuring the fridge with a kill-a-watt, it draws about 46W when running. Startup is hard to catch, but it seems to be around the 300-450W range for less than 2 seconds. The refresh rate of the kill-a-watt makes it hard to see the exact value, but it's very brief.
After a night with the furnace going, I've occasionally had issues where the inverter hits the low voltage cutoff when the fridge tries to state in the morning. The batteries still have plenty of energy to crank the big generator over, but that early morning voltage droop is irritating the inverter for the 2 seconds the fridge is drawing more power. I have the inverter mounted as close to the batteries as physically possible.
I had a few thoughts on what to do to remedy this:
1. See if there's a way to disable/modify that low voltage cutoff on the inverter. I've seen a thread here to do that on a different model. Given that the batteries are still able to crank the generator over quickly, I don't think I'm lacking in actual capacity; it's just the sag of the lead acid batteries under any sort of load gets them very near that 10V cutoff.
2. Look into some sort of DC-DC boost converter to give the inverter a more stable supply. Finding one that's 80-100A capable seems to be a challenge.
3. Upgrade to lithium batteries. The increased Ah rating is good, but what I'm really after is that flatter voltage curve. The Victron MPPT controller can handle them and I'd pair it with a good BMS. I dont think I'd need much else to complete the upgrade.
Any other suggestions for this setup? Also, is it recommended to leave the batteries and solar connected when the RV is stored, allowing the Victron controller to do its thing? Or is it better to disconnect everything when the RV is not in use to keep the cycle count low?