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Things that go beep......

Posted: Sun Jan 12, 2020 8:52 am
by JR.
For over a decade I have been trying to reduce the clutter caused by my packrat ways... When I recently upgraded my DSL modem the battery back up from the old one became mine to discard... I thought about it for a while but couldn't think of a good use for it so to the curb it went.

My town wide trash pick up day is the first thurs of the month, but this month I put my box of trash including the back up battery out a little late, so had to drag it back into my car port... It was turned off, but got rained on even sitting in my car port from the recent storms. Yesterday while out in my carport I heard a faint beeping sound and it took a while to zero in on the trash box. I disconnected the battery and it stopped beeping. :oops: Apparently the rain got inside and made it beep.

JR

Re: Things that go beep......

Posted: Sun Jan 12, 2020 12:57 pm
by terkio
It is crying. "Keep me".

Re: Things that go beep......

Posted: Sun Jan 12, 2020 3:07 pm
by JR.
The icon printed on the side of the huge rechargeable battery is also saying don't trash it....

JR

Re: Things that go beep......

Posted: Wed Jan 15, 2020 11:17 am
by terkio
Things that glow...
I had salvaged a bunch of security emergency exit lights from refuses.
The idea was to make good NiCa battery packs from the good cells.
When I trashed the left overs, all had been charged, I was sad to see long dying ones desperately glowing to stay alive.
I had kept a few of them, made all my effort to have friends adopt some, alas I could not keep more.

Re: Things that go beep......

Posted: Wed Jan 15, 2020 4:17 pm
by mediatechnology
I change UPS batteries every 3 to 4 years and keep the good old ones. I try to charge them every couple of months or they'll fail pretty rapidly.

I usually have enough for 48V. I think the last time I used them was to confirm hum was induced rather than PSRR.

Re: Things that go beep......

Posted: Wed Jan 15, 2020 4:51 pm
by terkio
UPS is something I used to salvage too.
Many go to the dump because of batteries that don't last and high cost of new batteries.
A trick is to get models that run on 12V, then any car battery is good for it.
A UPS is happy running that way, and this gives a fully charged battery ever ready.
What kills lead batteries is deep discharge. This is why UPS batteries fail. When kept charged and not allowed to go flat, they can last very long.
UPS management that makes sense is asking for power only for the time it takes for a clean shut down or switch over a generator.
48V UPS should run fine on truck batteries.

Re: Things that go beep......

Posted: Wed Jan 15, 2020 5:03 pm
by mediatechnology
My UPS are all 12V-powered and I have 6 of them.
I have thought about powering them from one of the cars if we had an extended outage and I couldn't run the generator for some reason.

Re: Things that go beep......

Posted: Wed Jan 15, 2020 8:27 pm
by terkio
mediatechnology wrote: Wed Jan 15, 2020 5:03 pm My UPS are all 12V-powered and I have 6 of them.
I have thought about powering them from one of the cars if we had an extended outage and I couldn't run the generator for some reason.
How much AC power could you get running UPS from a car alternator?

Re: Things that go beep......

Posted: Thu Jan 16, 2020 4:02 am
by mediatechnology
About 650 VA at most limited by the UPS.

Re: Things that go beep......

Posted: Fri Jan 17, 2020 2:08 pm
by terkio
Yes, this is the best I got to running with 12V battery. I can use one in my camping car.

For more power UPS run on 24V or 48V.
24V,48V cannot be done simply with 12V car batteries in serie, because of battery balancing, but may be this is no big deal.
There exist modules inside Li Ion battery packs that manage cells balancing. I do not know how this works exactly by I see this is known and available, may be applicable to car batteries.

What about managing packs of 12V car batteries ? Cheap and easy ?