View Full Version : Battery/Inverter questions

04-01-2012, 10:56 PM
I would like to install a 12v car battery in the small space of the sliding door floor area... to run my power inverter. The battery I found will fit well but has the forced on caps and I assume not totally sealed. I cant find a small battery box for this one but due plan to cover the top from shorts. how much do I have to worry about fumes? is this battery ok to use for this?

I run a 2500 sprinter and have a fold down bed attached to the bulk head... so I do sleep feet from this thing???


04-01-2012, 11:38 PM
What size battery? What are you reasonably expecting to run off this inverter? Be aware that most inverter are very inefficient and will consume a fair bit of power just inverting DC to AC. A small "car battery" might have ~75 ah of total capacity, but you will rapidly kill it (not just discharge it) by drawing it down more than ~ 10%. A "deep cycle" battery is designed to be drawn down 25-50%.

10% of 75 ah is 7.5 ah. At 12 vdc that is will give you about 90 watt/hours of power. Just to note a small flat screen might draw ~ 100 watts, so you could run that tv for less than an hour,, way less if you factor in conversion losses.

As we always say in the solar world, all hardware choices begin (and end) with the loads. Define the loads accurately, then figure out how much battery you are going to need, and then figure a proper charge regimen.

Good luck,


PS. I suggest that you read and understand the following links:



04-02-2012, 08:29 PM
Consider only using a sealed agm type of battery in interior spaces. No outgassing, no vents, superior performance, faster recharging, all around just the choice with no equal for your personal safety. When I added 2 to my passenger area I also changed out the vented lead acid under the passenger seat for equal charging and safety of course. Check them out and see what you find for yourself.