On 11/26/2014 2:31 PM, Tony Hwang wrote:
Percival P. Cassidy wrote:
On 11/26/2014 09:30 AM, KenK wrote:

While trying to come up with something more to worry about, I thought
of my
backup battery. I have a 12 v deep discharge lead acid battery with a
Battery Tender wall wart charger. I check the battery water level
monthly
(usually) and keep an eye on the charger indicator light. I see no
problems
but wonder if there was an easy way to be sure the battery will be
charged
when the power goes out and I need it for a light and, if summer, a fan.
Just trust the charger to detect a problem and warn me by changing the
light color or blinking? An easy test of some sort, other than turning
the
light and fan on for a half day or so every few months?

I can't think of anything (worth the cost) that's easier to do or more
accurate.
Does the battery do what you want when you ask it to do that?
Test doesn't get more relevant than that.

Never ask a question if the answer won't change the future.
In this case, if you run some "test", what are you gonna do with the answer?

If the light doesn't work, you have a clear definitive answer and
you know exactly what to do...go buy a new battery.


I suspect I'll
just
have to take my chances.

http://www.iotaengineering.com/pplib/spec2.pdf

And add the IQ4 smart-charge module.

Connect an el-cheapo multimeter (Hazard Fraught or the like) across the
terminals (permanently) but turn it on only to check the voltage from
time to time.

Perce

Hi,
EVen bad battery gives good voltage reading. When Load is applied nothing!