Guys,

I have some older UPS units for personal computers. Are APS LS 500s. Original batteries are dead.

I patched in an ATV battery to one and it still works. ATV battery is about 2-3x larger in capacity than the original. Obviously won't fit in case, but I really don't care.

Am interested in providing emergency power for a dial-up or DSL modem and wifi router. Perhaps a second one to power a laptop.

Are there sealed batteries that can be used indoors and are priced reasonably? Maybe a much larger car battery that is designed not to generate hydrogen when charging.

Thanks a bunch!

There are now Lithium Ion batteries intended for use in motorcycles on the market now... and they don't produce hydrogen, but they are somewhat pricey...

These batteries have the specific chagring circuitry to keep them happy and alive built into the battery...

Frankly what I'm comtemplating doing on my collection of APC-1500 UPS units is to pair up full size Deep-cycle marine batteries to them...

What to do about the hydrogen? The batteries will go into airtight containers into which I've cut holes for duct work, one duct going straight out the top (made of plastic clothes dryer vent) another duct going in the side into which a marine bilge blower will push air INTO the enclosure.

But worrying about hydrogen is worrying about the wrong thing... hydrogen gas explosions from charging batteries is very rare because hydrogen gas easily diffuses through most attempts at containment...

Hydrogen Sulfide is another matter... and most people are unaware that Hydrogen Sulfide gas is many times more poisonous than Hydrogen Cyanide... The difference is that the human nost is more than a thousand times more sensitive to H2S than it is to HCN, and only about 25% of people have the necissary gene to be able to smell HCN.

BTW H2S is also flammable and potentionally explosive.

AD

AD,

H2S also has an odor signature that is utterly unmistakable and for which human beings have a very high sensitivity. Is hardly an un-noticeable killer.

Do "maintenance free" batteries actually generate hydrogen any more? I thought the idea was to create an electrolyte that did not.

the rub with H2S is that it is actually more poisonous
than HCN.

and your nose can get "numb" to the smell if levels rise slowly.

for those 1/3 of the population that can smell HCN they can detect it in ppm concentrations.

H2S is detectable to everyone in 10ppB quantities.

However there is another problem with H2S... it is flammable and potentially explosive, HCN is not

AGM [Absorbed Glass Mat] batteries are permitted to use indoors or in a car passenger compartment.
There are three types ; car replacement battery, 'marine battery' [enought to start a boat engine but mostly for boat electronics ], RV battery [very deep discharge, basically for just running electronics.]

I use the very deep discharge type for amateur radio.If I need power for radio when not running the engine in my truck, emergency power when the power lines are down, or portable use when not near any other power source.

Never had any problems and many companies make them.Mine are Interstate Battery DCS [deep cycle series 70 amp/hour ]

I had a 48aH gell cell I used as my Amateur radio backup power "Go bad" last spring.

I came home and the whole house stank of H2S.

It's no fun mid-march when you have the windows open and fans blowing to disperse the gas...


BTW, if you DO use a sealed box for batteries with an exhaust fan ducted with dryer ducting to eliminate any gas/gasses
it is important to remember that batteries only outgas H2 and
H2S when charging, so I wired my fans to run only when I
had power off the commercial mains.

My current project-in-planning is to wire my house for low voltage lighting (LED) so I don't need to actually use my Kerosene and/or Coleman lanterns during an outage.

I can make 12VDC fairly easily and using it directly is easier
and more efficient than using inverters to make 117VAC.

I also recently aquired a broken pressure washer (dead pump)
that I'm making a bracket for to mount a 130A alternator to.
there isn't a whole lot I can't do with 130A of 13.8VDC available

What I really wish for is a 500w PC power supply that runs on a 13.8VDC input.

Why? frankly I think running on DC directly makes mre sense than taking line AC voltage to power a battery charger, and using that floated across a charged battery to run an inverter which in turn powers a DC supply inside the computer to make 3.3V, 5.0V and 12.0V

Any 19 Amp hour, 12 volt sealed Lead/Acid battery will work very well and last three years. I have to replace many of them every year in my Job. I have been using them in my home's UPS's and have no complaints. Shop around. you can fund them for under 20 bucks each.