Just noticed this this morning....

There's a mild odor coming from the battery of my car. It's been on a battery tender for about 6 months. The battery looks fine with just a little bit of water coming out the top. Is this normal? The light on the tender is showing the battery as charged - I just want to make sure everything it okay with it.

Thanks,
Joe

 

That's perfectly normal for a battery that is on a perpetual trickle charge.
I've been known to keep a few batteries on charge... Not shown in the picture below are the 16, 6-volt batteries that provide backup power for most of my house.
Just make sure the water level stays above the top of the plates and the voltage stays below 13.85 volts.

 

Holy inverters batman.

 

Yea, I know. It ain't pretty, but it isn't much money either. The backup units can be had for $30 from ebay after their built-in gel-cell batteries die of old age.
I get the batteries from work for the $5 core charge. Someone has a set of 4 and one goes bad, all 4 get replaced. I get 3 good ones for $15.
I got probably $250 in all of it... and a lot of work.
I'm just one of those people that goes nuts when the power goes off... like when there is a tornado.
And just to be totally cruel, when the neighborhood is plunged into total darkness, I have my big-screen TV on in the living room and I turn on the front porch lights. You know, when the power's off, people come out of their houses like rats leaving a sinking ship.
I just stand on the porch and say, "Is your power off?" and look over my shoulders...

and now,

 

When you *think* you need a panic button, you might want to keep thinking...

 

The batteries together will make about 800 amps@24 volts. If you've ever bumped the ends of jumper cables together, it's about 20 times that. If something goes wrong I have to be able to disconnect all of them from the backup units at once. It's just there for peace of mind and it was free.

 

haha, that reminds me of the movie "conspiracy theory" for some reason... That's awesome though, I guess if your area has brown-outs/black-outs often at all...
I was just curious what the odor was coming from the battery? Like acid? Like sulphur? Like...?

 

Supervisor, How did you integrate the inverters into your fuse panel?

 

What if you're not there and something goes wrong? I'm sorry, but that setup has fire hazard written all over it. Not only from the high current and questionable wiring, but from the hydrogen gas as well. I'm guessing your wiring wasn't permitted or inspected. If it should be the cause of a fire, your insurance co. will likely decline your claim.

 

haha that looks crazy. good thinking. I'm going to get a gas powered generator for my home.

 

Make that an LP powered generator. Closed fuel system and LP doesn't go "stale" or "bad".
They can sit for months and months and fire right up.

 

They aren't inverters. They are APC backup units. They have sockets on the back. I dropped 2 power feeds down to power the backup units then just pulled the cables from the breaker box down to them, put plugs on the end of the wires and plugged them up.
Like this:
Before: Breaker------------branch load
After: Breaker---socket =}plug----Backup unit socket =}plug---branch load
Switching is instantanious and it's all "user-transparent".

 

thanks

 

I thought all backup units used an inverter to convert from the dc to ac voltage. ..

 

You misunderstand. The DC disconnect is so I don't have to disconnect each of the 4 battery strings to work on it. I can't risk shorting it with a wrench. "Panic Button" is the name of the big red button on the disconnect, not the function of the switch.
Each backup unit has it's own 85 amp fuse in it. Each backup unit has it's own 14 amp circuit breaker protecting the output.
I'm not crazy. If you'll notice in the picture, just to the right of the DC disconnect is a 6" fan constantly pushing air over the batteries to disperse any hydrogen gas.
ah, the joy of living in Alabama

 

They do. They also contain a computerized switching and management system.
An inverter only converts DC to AC.
Backup units do that and also handle the line voltage monitoring and switching from line power to inverter power and back.
That's what I meant when I said they weren't inverters.