Complete beginner

[Eastcoastcolt]

Good day all. Complete novice here, I have an older travel trailer which I have permanently moved to a piece of property. I have a medically complex child 20 months old who requires a feeding pump to support him. I currently have a small system installed on this travel trailer consisting of 1 400 watt panel an epever tracer 30 amp mppt controller a 1000 watt pure sine wave inverter and 2 rolls s6 460 ah batteries. With the summer temperatures it's very hard to keep his food substitute at a good temperature in a cooler with a 5 year old opening and closing it ever 5 minutes it seems. I have a 4.3 cu ft mini fridge with freezer I plugged into the trailers 120v system but it seems to deplete the batteries very quickly (about 2 days with about 12 hours of direct sun per day) I'm unsure if my system would be able to handle it. The only information I can find on the fridge is that it consumes 327 wh per year. Presently I have the shore power cable plugged into my inverter, which powers the entire camper very well. All lights are 12v DC through the onboard converter and I'm worried about voltage loss through the shore power cable which appears to be 14/3 cabtyre, approximately 24 feet long. My question is am I losing alot of power through this cable? Should I plug the fridge directly into my inverter vs the wall outlet in the TT. Is there anything I can do to make things more efficient? Thanks in advance

 

[HRTKD]

If you're connected to shore power, the 120v refrigerator shouldn't be draining the battery at all.

Does the shore power cable route through the inverter?

 

[time2roll]

You are not losing any real power in the extension cord to the RV.

However I don't understand the battery setup. Are these 2x rolls batteries connected to the RV 12v system? I think by plugging in your main cord to the inverter you may also have powered up the RV converter and have created a power loop. Older RVs may have a low powered charger so you may not have immediately noticed the power loss.

 

[Eastcoastcolt]

If you're connected to shore power, the 120v refrigerator shouldn't be draining the battery at all.

Does the shore power cable route through the inverter?

No shore power. Just plugged into the inverter from the solar panel

 

[Eastcoastcolt]

You are not losing any real power in the extension cord to the RV.

However I don't understand the battery setup. Are these 2x rolls batteries connected to the RV 12v system? I think by plugging in your main cord to the inverter you may also have powered up the RV converter and have created a power loop. Older RVs may have a low powered charger so you may not have immediately noticed the power loss.

No they aren't connected to the trailers system. They are stand alone just for the solar. My fridge seems to deplete them rather quickly even on sunny days. Especially over night. I basically plugged the trailer into the inverter. The RV battery is long gone but I'm sure I'm still powering up the converter because I can hear it click when I turn the inverter on

 

[time2roll]

OK so you are losing some power through the converter to provide 12 volts vs. disabling the converter and connect the pair of batteries direct to the RV 12v system. Otherwise You probably need to double the battery and double the solar.

Do you have a propane absorption fridge? Also put a strap or latch on the fridge to keep the kiddo out.

 

[HRTKD]

Pulling the AC plug on the converter is a good first step. The converter will still pull a small amount of current from the battery, but this is usually so small you would have a hard time measuring it. This assumes you're using a quality converter.

 

[Just John]

From your description, unless the batteries are old and missing a lot of capacity, you need more solar power.
A second solar panel and/or charge controller might do the trick. 460AH of storage at 12 volts (even cut in half like you should to 230AH) is a lot of stored power. Likely it can run that fridge just fine, the solar is having problems keeping up.

 

[HRTKD]

An amp meter in the circuit to the refrigerator would help to confirm how many amps it is really pulling. Rated amps is one thing. Real world is another.

 

[Just John]

An amp meter in the circuit to the refrigerator would help to confirm how many amps it is really pulling. Rated amps is one thing. Real world is another.

He/she says it depletes the batteries in two days. That means:

1000 watt inverter is adequate.
Battery capacity is adequate for at least 24 hours.
Batteries are being depleted faster than they can be charged even with good sunlight.

Add more solar would be my conclusion.

 

[HRTKD]

He/she says it depletes the batteries in two days. That means:

1000 watt inverter is adequate.
Battery capacity is adequate for at least 24 hours.
Batteries are being depleted faster than they can be charged even with good sunlight.

Add more solar would be my conclusion.

For a good portion of that two days, the solar may be enough to handle the load and charge the batteries. But once the sun goes down, the load is just too much.

 

[Eastcoastcolt]

Everything is brand new. Less than 2 weeks old. I think I'm at about the max my charge controller can handle with the 400 watt panel amp wise. I based everything on a 50% discharge rate on the batteries. It's 2 6 volt batteries to give 12 volts. I really wish I would have done a bit more research on this. But left it up to a company to piece me together a system. A buddy of mine boondocks for weeks on end with lithium? Batteries and about 200 watts of panels and he seems to do just fine. Am I missing something?

 

[Eastcoastcolt]

For a good portion of that two days, the solar may be enough to handle the load and charge the batteries. But once the sun goes down, the load is just too much.

This is exactly the problem I'm having.

 

[time2roll]

Need to cut back on the continuous use 120v items. Use only the propane absorption fridge.

 

[Eastcoastcolt]

Need to cut back on the continuous use 120v items. Use only the propane absorption fridge.

Propane has been removed long before I got the trailer

 

[time2roll]

Yes to be all electric you are looking at way more solar. A small generator dedicated to charging the battery could be the easiest solution until you assemble a game plan. I assume your buddy has propane and fairly limited electric needs.

 

[Eastcoastcolt]

Yes to be all electric you are looking at way more solar. A small generator dedicated to charging the battery could be the easiest solution until you assemble a game plan. I assume your buddy has propane and fairly limited electric needs.

Yes he is. It's hard to believe this has a hard time running a small fridge. The prices for solar parts and pieces up here are nuts. I may look into tossing another 400 watt panel and another charge controller on it. Would be nice to at least be able to the run the weekend. Without worry

 

[Just John]

This is exactly the problem I'm having.

Battery and inverter are handling the load, add more solar. The maximum 30 amps from the charge controller with a 400 watt panel is right. How much more is what @HRTKD is trying to ascertain. Ideally with two, one facing east and one facing west would extend the time you get a charge during the day. But just two might not be enough.

 

[time2roll]

I am not sure these small fridges are all that efficient. Many RVs are now coming with residential (compressor) fridges and they seem to run longer on less battery that what you describe. Another option might be to get more battery so the solar can catch up while you are not there and have enough capacity to get you through the weekend. Or build a larger LFP battery to charge at home and bring out with you. Or give up frozen items and just use an ice chest like tent camping. Not sure what the best trade offs are to meet your needs.

 

[Eastcoastcolt]

I am not sure these small fridges are all that efficient. Many RVs are now coming with residential (compressor) fridges and they seem to run longer on less battery that what you describe. Another option might be to get more battery so the solar can catch up while you are not there and have enough capacity to get you through the weekend. Or build a larger LFP battery to charge at home and bring out with you. Or give up frozen items and just use an ice chest like tent camping. Not sure what the best trade offs are to meet your needs.

Leave it to me to be difficult ? I work shift work so when Friday evening comes around every couple weekends for me we like to pack the kids up in the SUV and drive over an hour away from home way back in the woods (25 min drive if you need something from the closest town if you forgot?) by the lake and just get away from everyday hussle and bussle. With the medically complex 20 month old the cars full just with his supplies. There's room for the cooler but the more ice and packs you bring the less room for food items. I've got just handy 3000$ into this system so far as I'm all about buying locally and helping the little guys out. I wish I would have done just a bit more research before buying. But we were all eager and over due to get away for a bit. So I'm sure you can all understand my frustration. For us dragging a generator and gas just isn't feasible with the fumes and smells involved and my littlest one. I'll try adding another 400 watt panel and a 30a charge controller and see what happens. I have a weeks vacation coming up so I'd like to have this sorted out soon. Thanks for all the help this far. I'll snap a few pictures of the setup when I'm back and hopefully others can learn from my mistakes.