Charge Controller and Batteries in RV Compartment

[chrisski]

If I were to design my battery compartment to look something like this, is there anything wrong?

I pulled the pic off the internet, and this pix seems to be real close to the space and battery sizes I'd use. The size would be GC2, I would use four of them, and they'd be AGMs. I'd have a couple of busbars, the combiner would be in the compartment, along with the charge controller. In a separate post I had, I'd never considered using wood for the battery box. If I did that, I may coat the wood inside the battery compartment with something that does not react with acids.
Battery Compartment.jpeg

[Bala]

I would have the batteries separated from the electronics just in case there is ever an over charge or battery failure. Its could be similar to the pic but with walls and a lid for the batteries with venting to allow for air flow through the box.

You need to ensure the charge controller has adequate air flow for cooling as well. I have just mounted a controller in the front of my caravan and as it may need to operate with the lid closed at times I have mounted a small PC fan under it to cool it.

[chrisski]

I would have the batteries separated from the electronics just in case there is ever an over charge or battery failure. Its could be similar to the pic but with walls and a lid for the batteries with venting to allow for air flow through the box.

You need to ensure the charge controller has adequate air flow for cooling as well. I have just mounted a controller in the front of my caravan and as it may need to operate with the lid closed at times I have mounted a small PC fan under it to cool it.

If I go with AGM batteries, do you think they need to be vented? If so, do you recommend a hood? I was under the impression that if an AGM battery vented, it would fizz battery acid more than hydrogen gas, so venting is a little different for those.

This will be in Arizona, so a fan on the charge controller would probably be a good idea. I could be using the solar when it’s up to 100 degrees out, and the compartment would be hotter, and add the heat of the controller. I’ll have to look at how those things are turned on and off. I met an RVr who used those fans in the back of his fridge, and that really improved the cooling to the fridge.

I appreciate the reply. The electronics and the batteries will be about five as far apart as in the picture.

[Bala]

Many people now have them inside cars and some even come new with them inside.

I always aim to have batteries in there own enclosure and vented. AGM are at the end of the day a lead acid battery and although it may not be overly common given the right conditions can gas and explode.

I have a fan at the back of my fridge to move air as well. The fridge fan and the controller fan are manually switched but they could be automated. In my case I am happy with them manually switched.

[chrisski]

I appreciate the ideas.

Venting the batteries would not be too terribly difficult. I already have a 2” hose installed with a hood to cover a single battery, and I would just get a hood big enough for all four batteries.

I’ve got most of the equipment for the install now. I just need to purchase some batteries, thicker gauge cable, and wood for the battery enclosure. I just wish the Arizona temps were not so hot so I could work on it now.

[NCmountainsOffgrid]

I have 4 GC2 flooded batteries(Duracell), with a 20a charge controller, and two 100w panels on the roof, and that's it... works fine for recharging the battery bank when the sun is available. I'm not sure why you'd need to 'build' such as elaborate wood platform and equipment setup, as a charge controller by itself is generally enough for a small simple solar array. My HQST panels package came with the small charge controller, wiring and 'Y' combiner connectors for panels, leading down and into the battery bay, and to the Charge Controller, which is simply easily mounted right above the batteries, actually attached via zip ties to the upper bracket, which holds the chassis batteries for my coach. The only thing I had to provide myself was the two simple wires that go from the Charge Controller output to the Positive and Negative battery bank terminals. The charge controller gives a continuous readout of the status of the panels, solar amperage output, battery level, etc. Nothing to it - about $300 total.

[Mike90250]

I have 4 GC2 flooded batteries(Duracell), with a 20a charge controller, and two 100w panels on the roof, and that's it.......

200W for your 4 batteries is a pretty minimal system and is unlikely to produce much acid mist or hydrogen. So... do you charge your batteries another way too ?

With flooded batteries, you are also doing monthly water checks and will generally know in advance, before a catastrophic failure occurs. Sealed batteries are more easily ignored until they stop working.

[chrisski]

I have 4 GC2 flooded batteries(Duracell), with a 20a charge controller, and two 100w panels on the roof, and that's it... works fine for recharging the battery bank when the sun is available. I'm not sure why you'd need to 'build' such as elaborate wood platform and equipment setup, as a charge controller by itself is generally enough for a small simple solar array. My HQST panels package came with the small charge controller, wiring and 'Y' combiner connectors for panels, leading down and into the battery bay, and to the Charge Controller, which is simply easily mounted right above the batteries, actually attached via zip ties to the upper bracket, which holds the chassis batteries for my coach. The only thing I had to provide myself was the two simple wires that go from the Charge Controller output to the Positive and Negative battery bank terminals. The charge controller gives a continuous readout of the status of the panels, solar amperage output, battery level, etc. Nothing to it - about $300 total.

I wouldn't mind seeing pics of what you have.

As far as the compartment, I need to do something different with the batteries, because where the one small battery is placed in my RV now, If I put four large RV batteries where my battery compartment is built in the RV, I will be picking them off the side of the road when they fall through the plastic floor. Actually, as cheap as these RVs are built, I'll probably find my one battery on the side of the road one day. For the 4 battery tray, I looked at fabbing some 1" aluminum angle or steel angle, but that can become pricey. Also, finding a seller who stocks a pre built, four position GC2 battery trays in a 2 X 2 configuration is impossible. The plywood seems to be the cheapest and easiest to work with option, and being in the RV, I'm not worried about it weathering. I'm also going to have an inverter in this setup, and that makes the installation quite a bit harder.

I'm glad you were able to find a decent solar kit. When I looked and started running some numbers like the wire size calculator to battery size, Inverter placement, the kits I found were actually dangerous. I think the companies can get away with that because they are from a foreign country not famous for quality control or regard for human life, and the company will be likely out of business by changing their name, probably to avoid liability. Either that, or the kits were grossly underpowered, kind of like a bait and switch. The company I started to order a kit from actually took my order, and came back to me a few days later and said we don't have that, but if you upgrade to this kit for this price, we'll get it sent to you in a few days.

All said and done, once my 600 watt 12 VDC 400AH system is built, it will cost at least 4 times what a kit off the internet cost, but I'll be able to sleep at night knowing that the power will be there the next day without me having to kick out a window to escape a fire. As exciting as that sounds, I've had enough excitement for one lifetime and just want to relax.