Increasing the available AH’s in RV with no solar

[MisterSandals]

I’d be surprised if you get more than about 5-6 Amps out of it honestly

Most of these deliver 20V @ 5A. Why is it surprising to get 5A out of it?
In quality sun and moved periodically to follow the sun, its not hard or unusual to get over 20Ah each day.

 

[quadna71]

Most of these deliver 20V @ 5A. Why is it surprising to get 5A out of it?
In quality sun and moved periodically to follow the sun, its not hard or unusual to get over 20Ah each day.

Correct - the Renogy unit is rated for a max of 5.56 amps. Like I said, I never have an expectation of it being a game changer. Still it never hurts to stick a little back in if the conditions are right.

 

[RVLiFe]

I’ve had one of those as well. Now I use it as a trickle charger for my boat. It’s really good at that but I don’t believe you will get 20Ah out of it unless you happen to be in perfect weather conditions. It just becomes too frustrating to use at such a low rate of charge. Think of it this way, it will barely replace the power that your single light above the living room chair will use in just 4 hours of use. It is better than nothing though and worth having.

 

[papab]

Does your camper have a 12v residential fridge? Ours does and it is a real power hog - hence going with the second battery. If it were propane we would have likely stuck to one. Since we don’t have panels up top and many of the Harvest Host locations don’t allow generators, we wanted to have that buffer of the second battery to give us better peace of mind. We fully understand that the upgrades will not be the end all solution, but at least we are sort of preparing ourselves for solar at some point down the road. Thanks for your response.

Is this a full house sized fridge? I have a 12 V Novakool and it uses about 2.2 amps, about 50% duty cycle, so less than 30 AH per day. Depends on the temp of course.

 

[papab]

I’ve had one of those as well. Now I use it as a trickle charger for my boat. It’s really good at that but I don’t believe you will get 20Ah out of it unless you happen to be in perfect weather conditions. It just becomes too frustrating to use at such a low rate of charge. Think of it this way, it will barely replace the power that your single light above the living room chair will use in just 4 hours of use. It is better than nothing though and worth having.

I look at it this way, In the summer, out west, there are plenty of days you will get 20ah or more out of it and that's almost enough for camper van with LED lights and a small fridge.

 

[RVLiFe]

I look at it this way, In the summer, out west, there are plenty of days you will get 20ah or more out of it and that's almost enough for camper van with LED lights and a small fridge.

I did say it was worth having and that I use one as a trickle charge for a boat. You did mention a couple of key words though, West and almost. Which is why I recommended to plan ahead for a future upgrade. I think a lot of us started with a system like this and they are great for what they are and they can still be put to use even though some of us have moved on. Honestly, I look at some of the systems that some of the other users on here have set up and I feel my system and knowledge is peanuts in comparison to them. I can only aspire! But this forum has really helped and there is no shame in starting small and if I offended I apologize. Living in Wisconsin, those sunny and perfect days are far and few between and it didn’t take long for me to realize the limitations.

 

[quadna71]

Is this a full house sized fridge? I have a 12 V Novakool and it uses about 2.2 amps, about 50% duty cycle, so less than 30 AH per day. Depends on the temp of course.

Not sure if it is considered full house sized, but it is 10.7 cu ft and it says it uses a max of 11 amps. Here's the sticker inside the door:

https://flic.kr/p/2mYZoD8

 

[12VoltInstalls]

in all likelihood even the simplest of charger will have also improved over the next year or two

That will happen. But I wouldn’t count on it in the RV world. They move at the pace of ‘just enough’ to sell; they rely on an uninformed buyer.

 

[Swamplizard]

Flat solar panels on my RV/Van have disappointing performance in the winter months even down here in FL. You may want to consider a small Orion DC to DC converter/charger so when you are driving, you are charging. Just a thought.

 

[12VoltInstalls]

Flat solar panels on my RV/Van have disappointing performance in the winter months even down here in FL

Flat or vertical is a poor compromise
Maybe FL latitude is different results but vertical panels work surprisingly well up here near the Canuckistan border in winter.

In summer I give up a lot I think but in good sun I was fully charged before 9am with 1/2 my current watts of panels so I guess it doesn’t matter to me.

 

[papab]

Not sure if it is considered full house sized, but it is 10.7 cu ft and it says it uses a max of 11 amps. Here's the sticker inside the door:

https://flic.kr/p/2mYZoD8

Mine is 4.3 CF, so yours is about 2.5x. So maybe 75 ah/day? If you can measure/estimate average energy use it would very good information. 400ah is probably overkill, but if you can't charge from the truck or solar it may make sense, and if the fridge really uses 75ah/day, 200 ah might be marginal.

 

[papab]

I did say it was worth having and that I use one as a trickle charge for a boat. You did mention a couple of key words though, West and almost. Which is why I recommended to plan ahead for a future upgrade. I think a lot of us started with a system like this and they are great for what they are and they can still be put to use even though some of us have moved on. Honestly, I look at some of the systems that some of the other users on here have set up and I feel my system and knowledge is peanuts in comparison to them. I can only aspire! But this forum has really helped and there is no shame in starting small and if I offended I apologize. Living in Wisconsin, those sunny and perfect days are far and few between and it didn’t take long for me to realize the limitations.

I apologize if I offended I just thought you were being pessimistic. Don't come West, the sun will fry your midwestern skin! I actually still have 1/2 of a 100 W suitcase panel (it got run over by a friend camping next to me) & I still use it in the morning and evening occasionally even tho I have 350W on the roof.

 

[quadna71]

Mine is 4.3 CF, so yours is about 2.5x. So maybe 75 ah/day? If you can measure/estimate average energy use it would very good information. 400ah is probably overkill, but if you can't charge from the truck or solar it may make sense, and if the fridge really uses 75ah/day, 200 ah might be marginal.

Unfortunately I didn't find a way to measure the average daily usage prior to wrapping up this past camping season. Of course now, in conjunction with the battery upgrade, I'm installing a Victron Smartshunt that can track the daily amp consumption for me. But even if I had it all finished today, I think the results wouldn't be typical of our normal usage as the temps have been 20-35 degrees Fahrenheit over the past couple weeks and the fridge would likely cycle much less. Even if the cabin of the camper is heated I think the back of the fridge which is against the skin of the slide would affect how hard it works at keeping things cool.

Once things pick back up this spring I will be logging all that data to help me predict just how long I can stay unplugged.

 

[rmaddy]

Flat solar panels on my RV/Van have disappointing performance in the winter months even down here in FL.

What percentage are you getting?

To add a data point, the flat mounted panels on my trailer got to 45% rated wattage at 11:15am yesterday. It would have reached about 55% but the battery was full before noon. I'm at about 40.5ºN latitude. The temperature at the time was about 38ºF. Right now, as I type this at about 10:40am, my panels are at 38% at 31ºF and everything in the shade is covered in light frost.

 

[quadna71]

Weather is definitely not cooperating. I’d like to get the underbelly opened up and start rerouting the cables, but of course another 12” of snow is forecast between now and tomorrow afternoon. Can’t wait to get this ball rolling!

 

[quadna71]

I made some progress today. Mounted plywood vertically and horizontally, boxed in the base of the batteries and then anchored them with straps. Also mounted the shut-off switch, 60A fuse, and the battery-monitoring shunt. After looking back through this thread, I’m pretty sure I forgot to reverse the order of the shut-off switch and the fuse, but I can switch them around in 5 minutes the next time I’m in there working on it. I still have to drop the belly panel, run the wires down from under the bed to below the camper, and over to tie into the charger cabling. I also have to replace the FLA charger with the LiFePO4 charger. After those last two boxes are checked then I can flip the shut-off switch and start programming the Victron shunt. Once that is all dialed in then I will finish boxing in the whole kit under the bed so that half of the space can be used to store extra blankets. Still waiting for warmer weather before doing the work under the camper. 23° F outside right now and I don’t feel like laying on that cold ground!