How many amps? 8 fully charged 225 amh 6v batteries in series? Trying to derive amps, not amp hours. Thanks

[BobbyP]

googled the model number from the sticker. Inexpensive amazon fridge popped up, this is what its claiming. (if we want to believe the Chinese specs)
1.2a @115v = 138w/24v = 6amp

1.2a seems a tad low for the cheep compressors these have.

Thanks for your generous input. It's a little past 4 am and I'm somewhat relieved as the freezer has run through the night with some 80% left in the battery. It's about 60° from yesterday's high of 84° with full sun.
Will be closely monitoring as clouds are coming and sun is waning.
If the SCC doesn't show the correct amperage I'm gonna just live with it. The set up works for my meager means.
I'm grateful to all who took their time to to be of assistance. BobbyP out.

 

[mikefitz]

The fridge specification says 256kwh per year, 29.96 watts an hour average. Its on a big yellow label.
All compressor frighes cycle with variable on off times.
All small compressors fridges have typical power consumption in this region.
1.2 amps is the compressor running current at 115 volts, 138 watts. It will not run all the time so the manufacturer indicate the power
consumption over a year.
The bank is 8 off 6v ,225 Ah batteries in series parallel, 450 Ah at 24 volts, 10800 watt hours.
Assuming 50% discharge, that's 250 Ah to play with. Even using your numbers as a worst case, thats 1.6 days.
I have installed a number of compressor fridges in boats and RV to know typical power use, and can assure the OP, that even with no solar contribution, the fridge will run for over 3 days.
With a more efficient inverter with low standby power even longer.

Mike

 

[BobbyP]

The fridge specification says 256kwh per year, 29.96 watts an hour average. Its on a big yellow label.
All compressor frighes cycle with variable on off times.
All small compressors fridges have typical power consumption in this region.
1.2 amps is the compressor running current at 115 volts, 138 watts. It will not run all the time so the manufacturer indicate the power
consumption over a year.
The bank is 8 off 6v ,225 Ah batteries in series parallel, 450 Ah at 24 volts, 10800 watt hours.
Assuming 50% discharge, that's 250 Ah to play with. Even using your numbers as a worst case, thats 1.6 days.
I have installed a number of compressor fridges in boats and RV to know typical power use, and can assure the OP, that even with no solar contribution, the fridge will run for over 3 days.
With a more efficient inverter with low standby power even longer.

Mike

Thank you Mike. Your input is most reassuring and welcomed. As the unit has run all night with +< 80% battery reserve, I'm feeling like this exercise is in the rearview mirror and getting smaller.

 

[Goboatingnow]

The fridge specification says 256kwh per year, 29.96 watts an hour average. Its on a big yellow label.
All compressor frighes cycle with variable on off times.
All small compressors fridges have typical power consumption in this region.
1.2 amps is the compressor running current at 115 volts, 138 watts. It will not run all the time so the manufacturer indicate the power
consumption over a year.
The bank is 8 off 6v ,225 Ah batteries in series parallel, 450 Ah at 24 volts, 10800 watt hours.
Assuming 50% discharge, that's 250 Ah to play with. Even using your numbers as a worst case, thats 1.6 days.
I have installed a number of compressor fridges in boats and RV to know typical power use, and can assure the OP, that even with no solar contribution, the fridge will run for over 3 days.
With a more efficient inverter with low standby power even longer.

Mike

firstly this is a freezer not a fridge

secondly the energy label , assuming its to EN150 is a very " vague " number, the test specification is over 24 hours at ordinary ambient and minimal door openings . Often the real world numbers are considerably different, its use is largely as a comparative number not a consumption number

using it to run battery discharge cals is highly fraught

 

[RCinFLA]

256 kWH/yr. is average of 701 wH's per day. That is about right for a 14-16-ish cu-ft refrig. 1 kWh/day is typical for a mid-sized refrig in 17-19 cu-ft range. Freezers are typically lower power since they are opened less often and with door top opening, they allow less warm damp outside air intrusion when opened. This also goes for a refrig with bottom drawer freezer. Side by side doors are the worst. Number will vary depending on how many times you open door of refrig a day and the temp/humidity of their surroundings. Don't expect that number if refrig is located in a warm garage, might get better if located in cool basement not only due environmental coolness but a basement refrig probably will get opened less during the day compared to a kitchen located unit. Refrig power consumption is proportional to the number of kids you have.

There is defrost cycles that typically occur every 15 to 20 hours so a daily number average is fairly accurate. Any shorter period of time measurement may have, or not have, a defrost cycle power included which can swing the watts/hour consumption average observed. Best way is just to put a Kill-A-Watt meter in line with AC plug and let it accumulate watt-hrs for a week with your typical use case. Right after you get back from grocery store, open door a lot and put warm stuff in refrig it will draw more power for a few hours afterwards.

For inverter sizing you should know what the peak defrost current and startup current is.

Defrosters wattage can vary. Some units have high wattage heaters with short duty cycle, some have lower wattage defroster with longer duty cycle. I have seen as high as 1kW and as low as 100 watts for defrost power. Don't think you can disconnect defroster to save power. Depending on room humidity, usually within a day or two there will be enough frost building up on cooling coils to result in compressor running longer, consuming more power than you saved by disconnecting defroster. Some folks try to convert a freezer to be used as a refrigerator. Be aware that a freezer defroster may not be designed to handle the amount of frost build up that a refrigerator application gets due to more frequent door openings.

For measuring startup current it is important you leave unit off long enough to allow refrigerant pressures to equalize, and if it has a start capacitor PTC thermistor to disconnect start cap after startup, PTC thermistor needs time to cool down. 25-30 minutes should be good enough. Do not short cycle power when running from a small-ish wattage battery powered inverter. The extra startup current may overload the inverter causing it to shut down.

A lot of folks first playing with battery power inverter to run refrig will short cycle unit to point where compressor overheats. When compressor cuts out due to thermal overload it can take couple of hours before it cools down enough to get it to startup again.

 

[BobbyP]

256 kWH/yr. is average of 701 wH's per day. That is about right for a 14-16-ish cu-ft refrig. 1 kWh/day is typical for a mid-sized refrig in 17-19 cu-ft range. Freezers are typically lower power since they are opened less often and with door top opening, they allow less warm damp outside air intrusion when opened. This also goes for a refrig with bottom drawer freezer. Side by side doors are the worst. Number will vary depending on how many times you open door of refrig a day and the temp/humidity of their surroundings. Don't expect that number if refrig is located in a warm garage, might get better if located in cool basement not only due environmental coolness but a basement refrig probably will get opened less during the day compared to a kitchen located unit. Refrig power consumption is proportional to the number of kids you have.

There is defrost cycles that typically occur every 15 to 20 hours so a daily number average is fairly accurate. Any shorter period of time measurement may have, or not have, a defrost cycle power included which can swing the watts/hour consumption average observed. Best way is just to put a Kill-A-Watt meter in line with AC plug and let it accumulate watt-hrs for a week with your typical use case. Right after you get back from grocery store, open door a lot and put warm stuff in refrig it will draw more power for a few hours afterwards.

For inverter sizing you should know what the peak defrost current and startup current is.

Defrosters wattage can vary. Some units have high wattage heaters with short duty cycle, some have lower wattage defroster with longer duty cycle. I have seen as high as 1kW and as low as 100 watts for defrost power. Don't think you can disconnect defroster to save power. Depending on room humidity, usually within a day or two there will be enough frost building up on cooling coils to result in compressor running longer, consuming more power than you saved by disconnecting defroster.

For measuring startup current it is important you leave unit off long enough to allow refrigerant pressures to equalize, and if it has a start capacitor PTC thermistor to disconnect start cap after startup, PTC thermistor needs time to cool down. 25-30 minutes should be good enough. Do not short cycle power when running from a small-ish wattage battery powered inverter. The extra startup current may overload the inverter causing it to shut down.

A lot of folks first playing with battery power inverter to run refrig will short cycle unit to point where compressor overheats. When compressor cuts out due to thermal overload it can take several hours before it cools down enough to get it to startup again.

All good info...your time and input is much appreciated.