Fridge won't start at night
- Thread starter hfraser
- Start date
12VoltInstalls
life passes by too quickly to not live in freedom
Yikes. $2000. I know they have a great reputation but my latest fridge tries are 5CF for $200 and 7.5CF for $216.99
The inverter inefficiency is easily made up with $400 of additional panels and there’s still moula leftover.
That’s why mine are 4P2P
I’m betting that will work.
My gut says you aren’t having a power delivery issue, just a startup spike issue.
I have not measured my current fridge but the prior ran at about 60W but was ~900W+ on startup for barely two seconds.
My midsized shopvac runs ~800-850W but an MPPSolar 1012LV-MK won’t start it; the 1200-watt Giandel didn’t care even though the startup on my meter sometimes cruised over 2000W for not long enough to read the actual number.
I think you’re close and for $25 that’s super cheap to beat the game. I need to try one.
littleharbor2
Solar Addict
I suspect this is a typo.
12VoltInstalls
life passes by too quickly to not live in freedom
No. Not a typo.
I have two banks of four 12V lead acid batteries in parallel with balanced cables and the two banks are parallel on a terminal post for 12VDC
efficientPV
Solar Addict
- Joined
- Sep 24, 2019
- Messages
- 1,231
Don't waste your money on a capacitor unless it is a supercapacitor. I've seen fridges run off these and no battery. For example, I use a 6,000uf capacitor in a project and that can supply less than a millisecond of power. My fridge start up current lasts 2.2 seconds. I looked back to start of thread and couldn't see what inverter you are using. I recently had starting issues with my fridge due to the battery being 6 years old and at its end of life. Startup current was close to 120A at 12V. I've been thinking of going to a 100AH Lipo, but that surge would put it on the edge and probably wouldn't be reliable. So, I tried a little mod to the inverter I wanted to do for years. Now the peak surge is closer to 60A and this battery will make it thru the season. My battery options are now open for the next one.
12VoltInstalls
life passes by too quickly to not live in freedom
Really looking forward to seeing how the capacitor works out.
Me too. But it will now not be till spring. We are northwest of Quebec City in rural Quebec 25 miles into the mountains on bad logging roads. Tonight will just about hit freezing, so tomorrow we close up the camp for the winter. I will likely return with both the capacitor and inverter to try them both... if the capacitor works, the inverter goes back.
On a side note, I have 4 batteries connected in series/parallel. I just checked and the one series pair is unbalanced with the other so I will top the lower one up. If I am looking at 14.4V and charging till the current draw drops to 2 amps, can I leave the two batteries connected and set my power supply to 28.8V? Less stuff to disconnect. The two batteries in each series pair are within .02V of each other.
On a side note, I have 4 batteries connected in series/parallel. I just checked and the one series pair is unbalanced with the other so I will top the lower one up. If I am looking at 14.4V and charging till the current draw drops to 2 amps, can I leave the two batteries connected and set my power supply to 28.8V? Less stuff to disconnect. The two batteries in each series pair are within .02V of each other.
sunshine_eggo
Happy Breffast!
Are you saying:
1) When you charge each string individually to 28.8V, the 12V batteries in that string are within 0.02V? That's great.
or
2) Sitting there on the bench, one string is 25.6 and the other is 26.2 (random numbers for illustration sake, but significantly under 28.8V).
If 1), then the batteries are balanced. Great.
If 2), then there is no strong evidence the batteries are balanced. Balance matters 99% at absorption voltage, 1% anywhere else.
IMHO
build your 2S2P bank.
Charge to 28.8V with solar and hold there.
Measure 4X 12V batteries.
If voltages deviate by more than 0.1V, apply the power supply set to 14.4V to the lowest voltage battery.
2s2p pack is built but sun isn't cooperating. Each battery in a series pair is .01V from the other, but the 2 pairs are .6V from each other. I want to know if I can charge the lower voltage series pair using my programmable power supply set to 28.8V and wait for the current draw to drop to 2 amps.
littleharbor2
Solar Addict
So in other words 8p
sunshine_eggo
Happy Breffast!
Might as well just wire the whole bank and charge to 28.8V. Monitor 12V for equal voltage.
12VoltInstalls
life passes by too quickly to not live in freedom
No.
4 parallel batteries arranged to be balanced. Twice. 8p doesn’t describe the cabling. And the cabling solves most of the balanced charging concern posted earlier. Which is why I posted.
Batteries balanced to within .1V of each other. A day of sun producing about 4 hours at 600 watts. Batteries pretty much charged. And as soon as the fridge compressor tried to start at about 17:50 (getting darker here, down to less than 100 watts from the panels), the inverter cuts out. So I will look forward to trying the big ass capacitor next June once the roads are clear of snow and we can get back to the camp. Assuming the clouds of black flies don't obscure too much sun, I hope to see a fridge start in the dark 
But I will bring a 3000 watt inverter too, just in case.
Thanks for everyone's advice. It feels like I'm close to a solution.
But I will bring a 3000 watt inverter too, just in case.
Thanks for everyone's advice. It feels like I'm close to a solution.
sunshine_eggo
Happy Breffast!
At peak charge voltage? If so, I believe you've sorted the batteries out from a balance perspective. Hopefully, they'll improve over time. It's also time to check the specific gravity.
Connection or inverter.
So I will look forward to trying the big ass capacitor next June once the roads are clear of snow and we can get back to the camp. Assuming the clouds of black flies don't obscure too much sun, I hope to see a fridge start in the dark
Cap shouldn't be necessary, but it sounds like fun.
This is probably the fix.
12VoltInstalls
life passes by too quickly to not live in freedom
Well the curiosity of the capacitor is killing me
He says you'll be waiting until next June. Hope you have something else to entertain yourself with until then.
Checkthisout
Solar Wizard
- Joined
- Nov 14, 2021
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- 2,597
After what seemed like a prominsing start, the problem is back. So to eliminate the batteries, I connected my meter with the hold function to the 2,0 cables connection to the inverter and turned on the fridge with solar panels disconnected. The inverter alarmed, but I never saw a dip in the voltage from the batteries with the meter set to hold at the minimum voltage. No drop at all, indicating (I think) that the inverter is not reacting to slump in the voltage from the batteries, but something else. Is it possible my 245V 1500W/3000W surge inverter needs to be replaced with a larger unit? I know it's been suggested already, and this seems to confirm that even though it should be able to handle it, it's not. If so, does going to a 3000W unit the appropriate size? Everything in solar seems to indicate taking whatever the specs say and double it
Don't know the inverter but make sure it's tripping on undervoltage and not a ground fault.
I don't think it would be a ground fault... I have a 3ft stake into the ground sheltered from the elements with a 6 ft wire connected directly to the charge controller and the inverter. Plus it runs fine from about 10:00 to dusk. Have I done enough to rule out ground fault?
