Inverter/Charger for use with horrible park power? RV to run soley off Solar/Batteries.

ryankenn

New Member
Joined
Aug 2, 2022
Messages
7
Hello!

I posted in the welcome forum but I thought I would move this to the proper forum.

Our park (seasonal) has horrible voltage. Up until this weekend my plan was steering toward a Victron Multiplus II to limit shore current and supplement the power using solar and batteries. But this weekend exposed how bad the park can get, it was down to 87V when I was pulling 15A, so with my Hughes Autoformer I was seeing 95V inside. I now think I want to totally isolate myself from the shore.

So I am wondering what product I should be looking for. I was hoping it could still have a charger section where I could limit draw to maybe 8A (then park power would be 95V or higher) so that shore could supplement solar for charging the batteries. But I don't want it passing shore to my RV, only charge. When I talked to Victron PowerAssist will just supplement the current, if I am feeding it 95V it will pass 95V on to my trailer.

Should I just be looking at a couple of products instead of an all in one? Like a 95-120V input capable charger, then a separate inverter and MPPT?

We only go up for two nights at a time, 3 days max. I have a monitor on it and he usage for our longest time in trailer is 41.2kwh in a 44 hour period. That period contains about 20 hours of largely direct sunlight.

So for safety I want to say I need to supply 45 kwh in a 48 hour period with 20 hours of sunlight. I can fit (4) solar panels, looking at 220W panels. I feel safe in pulling 8A from shore as a charger.

Calculators for sizing the batteries aren't really clear for this kind of setup, nor do I know what kind of product I should look at. The trailer is 30A so I would want to size for that so we can use the trailer as intended.

Any ideas are appreciated.

Thanks
Ryan
 

time2roll

Photon Sorcerer
Joined
Mar 20, 2021
Messages
4,060
Skip the all in one and just use the autoformer into a smallish RV converter. Maybe 45 amps at 12vdc rating.

Separate MPPT to match the solar.

Separate inverter maybe 2000 watts. If going 3000 watts I would step up to 24 volt battery. This will give the correct 120v to the appliances. The victron will do power support but not voltage support.

I would have 400+ Ah of battery with room for expansion.

My trailer is set up like this and works beautifully.
 

ryankenn

New Member
Joined
Aug 2, 2022
Messages
7
400 ah at what voltage? I was looking at the EG4 Racks, and a 48V 100ah is about $1500 but is 5.12kwh.

Is the RV Converter separate from the one built into the trailer?

I would like to see more info on your setup if you care to share. Especially what batteries you chose.
 

time2roll

Photon Sorcerer
Joined
Mar 20, 2021
Messages
4,060
I did a DIY build with LFP cells and BMS for a battery.

Yes the existing converter might work fine depending on model.

the 400Ah at 12v would be the minimum I recommend to drive a 2000 watt inverter. Yes a 48v 100ah is fine to drive 2000 watts. Not sure what the total power expectations are. OK to go on the small side as long as the battery can supply the amps needed without stress.

The utility power would seem to supply 50 to 80% of the energy. The rest would need to be battery or solar. With 10kWh battery maybe no solar is needed. Just leave with a depleted battery to charge during the week. Can conserve power if needed or add solar if needed. How this is balanced will be your call.
 

ryankenn

New Member
Joined
Aug 2, 2022
Messages
7
Well on average we are using about 1800 watts when the AC is on, 450W when off. Its on pretty steady for about 4 hours of the day, but that is in large part to how poorly it runs off 100V. The fan is slow and we can't use High fan as it draws too much current. If it was fed 120V and I could put the fan on high for the hottest parts of the day it would most likely actually cycle on and off as it could get the temp down quicker.

In my scenario using Utility power is a last resort, I would prefer it only charge the batteries and I run solely off the batteries. Otherwise I am exposed to the low voltage again. And its hard on everything in the trailer.
 

Rocketman

Solar Addict
Joined
Sep 27, 2020
Messages
820
Get a 3000w inverter for the a/c. You want/need a little more margin than a 2000w inverter can supply.

I like your idea of just connecting the shore power to a charger and using that charger to recharge the batteries. That way you get good clean 120v power in your rig. Look for chargers that can handle wider ranges of incoming power.

A 48v 100ah battery will run the A/C for about 2hrs (if I remember correctly). The solar will extend that slightly- having the charger plugged into the grid will help (but will depend on the size of the charger). You may need two batteries.

Good luck
 
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