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john monge 10-16-2012 05:36 PM

Solar storage battery and inverter
Where should batteries and inverter be mounted (indoors or outside)? I read that while batteries are charging they emit a flammable gas. I also read the inverter may create a spark. This sounds like a dangerous combination. How far away should the inverter be mounted from the batteries to avoid igniting the gas? Should one or both items be mounted outdoors?

Also, what is the relationship of batteries to inverter? If I have 1 12V battery, does that mean I need a 12V to 120V inverter? If I have 4 batteries, does that mean I need a 48V to 120V inverter?

ptarmigan61 10-16-2012 09:18 PM

A couple of questions here.
The inverter can be anywhere as long as you don't put them in a place too close to batteries to avoid corrosion. The batteries need a ventilated space, which is why
I put mine in a separate room with ventilation under the building. You may also want the inverter in a handier place to operate than the batteries.
The exact inverter spec depends on a few different factors; how far from batteries to inverter, what othe (DC) equipment are you running. Given the same amp hours for a given set of batteries, the way you wire them trades amps for volts, but the total watts stay more or less the same (ohms law).
So, four batteries (12v) can be wired for 12, 24, or 48 volts. If each battery is 200 amp hours, than you can get 12 v @800 amp hours for 9600 watt hours, 24 v @400 amp hours for 9600 watt hours, or 48 v @200 amp hours for - you guessed it - 9600 watt hours. BTW, you only want to rely on 50% to 60% of that total capacity. Draining batteries completely kills them in no time.

john monge 10-19-2012 06:29 PM

Sorry for taking so long to respond. I just figured out how to say thanks. Your info was very helpful.

john monge 10-19-2012 06:29 PM


ptarmigan61 10-19-2012 08:20 PM

Just glad it helped. Kind of surprised more people didn't weig in.

vsheetz 09-19-2013 11:02 AM

If sealed batteries, such as AGM, the inverter can typically be with the batteries. If wet batteries, which emit flammable gasses then the inverter is typically separated or the area must be well ventilated. The inverter install instructions typically will speak to the requirements.

The DC input voltage of the inverter is matched to the voltage of the battery bank, regardless of how many batteries make up the battery bank.

RV Example: I have four 6 volt wet batteries wired series/parallel for a 12 volt battery bank, and a 2300w inverter located in a separate compartment.
