Maintenance free car batteries indoors

dennis123123 · May 11, 2012

This might not be the right place to ask really... but here goes.

As I understand it, vented car batteries give off hydrogen when charging, and a nasty acid mist. I.e. DO NOT CHARGE INDOORS!
Looking at what's currently available, I see items labelled as "maintenance-free", which I understand to mean valve regulated sealed lead acid.

My question is; just how "sealed" are these maintenance free car batteries? Will they only vent gas if something bad happens (over charge etc)? And for all normal uses, they remain "safe" to charge and use indoors?

I'm trying out some solar based emergency power type stuff, and yes, I know I should (and will eventually) use a deep-cycle battery... but for the time being, a car battery is a cheap alternative even if it doesn't last too long.

Knobhead · May 11, 2012

Still keep them well ventilated with a free flow of air.

I for one would not have them in the house. Something goes wrong and it's not only you but you're familey that will be sat on a cloud playing harps!

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jimmymac · May 11, 2012

Even the maintenance free batts still release gases, i think the idea is that you can't get access to the cells & the acid but if you look closely at them they still have small vents on the side

Spazz · May 11, 2012

Personally I would never leave them unattended ever!

They all give off gases and can explode under fault conditions!

Its always better to charge them in the day - for what you are using them for I would put them into a fire proof container which is vented to the outside.

I have seen batteries explode into flames because someone walks into a garage next to the charging bay smoking a smoke, if a smoke can do that think about a spark from anything even a boiler lighting up

Spazz · May 11, 2012

jimmymac said:
Even the maintenance free batts still release gases, i think the idea is that you can't get access to the cells & the acid but if you look closely at them they still have small vents on the side

Exactly Jimmymac

maintenance free batteries don require topping up with acid or the acid replacing when they get old.

Strima · May 11, 2012

Maintenance free is a con dreamed up by the battery manufacturers, stops you topping up when the electrolyte levels get low and have to buy a new battery. They should be called 'reduced maintenance and cost you more than distilled water to replace' batteries.