[QUOTE=CDan;2164325]That setup is a great way to start a fire and/or release toxic gases. [/QUOTE]
Hydrogen isn’t a problem unless it builds up but since hydrogen can migrate THROUGH solid metal this usually isn’t much of a problem unless you provide a source of ignition next to the source
(like smoking a cigarette next to a car battery on a rapid charger)
The REAL danger is Hydrogen Sulfide which if you do a little research is actually more toxic than Cyanide Gas (Hydrogen Cyanide), but (and this is the good part…) while only about 30% of humans can smell cyanide EVERYBODY can smell Hydrogen Sulfide…
Those people who can smell cyanide can only smell it just before it reaches the toxic threshold, people can detect hydrogen sulfide when it is only present in parts per billion… around 1/1000th of the toxic level.
It is a concern? yep.
Is it as much a concern as the side-effects of the STRESS created
by losing data from even a momentary power outage? I really
sincerely doubt it.
If you ARE worried put the batteries in a coleman cooler that you have modified by attaching a length of ELECTRIC (plastic) clothes drier exhaust ducting and that you force ventilate with a fan.
Using the aluminum duct intended for Gas driers can get ugly because of what hydrogen sulfide does to aluminum.
BTW1 buy a used coleman cooler at a garage sale or thrift store, buying a new one is kinda silly if you are going to cut a 4" hole in it for the muffin fan
then store a couple lead acid batteries inside…
BTW, don’t bother running the fan off the 12V side, batteries produce
their toxic gasses when being charged, Hydrogen when being charged normally, hydrogen sulfide when being overcharged (or charged when the water level is low.)
Do pay careful attention because while most UPS’s have multiple batteries
they can use either 6V or 12V batteries.
I’ve seen UPS units that run off any voltage between 12 and 48V
using various battery setups you must do the same.