On Sat, 20 Jan 2018 10:44:21 -0500, micky
wrote:

In alt.home.repair, on Wed, 17 Jan 2018 19:16:41 -0600, philo
wrote:

On 01/17/2018 06:22 PM, wrote:
On Wed, 17 Jan 2018 17:48:13 -0600, philo wrote:

On 1/17/2018 4:32 PM, Andy wrote:

I was an industrial battery service engineer and any battery used inside
your house should be VRLA. Valve regulated lead acid, for safety
reasons. A standard car battery emits hydrogen and could be explosive.

As far as using a battery larger than what the unit was designed for,
you can do that...I do it myself. Just check the voltage periodically as
it should "float" somewhere around 13.5 volts.

If it ever drops to 12.7 or below, you will need to use an external
charger to boost it.

Is there any significant difference in the charging of a regular deep
cycle battery and a gel cell like they use in a UPS? I am not sure I
would want to use a regular starting battery since they do not like
being severely discharged.

On my first UPS, when the first battery wore out, I broke the thin
plastic ribs out of the case and put in a battery, of the same type, but
twice as big.


The same case is used on the APC 350 and 500 units - with a rib cast
in to keep the 3.5Ah battery from rattling around in the case of the
350. Cut out the rib and a 7 or 8 ah battery fits. I've done that a
lot, as the 7-8 ah battery is easier to find and about the same price.

The automotive maintenance-free batteries, instead of being
lead-antimony are lead-calcium.

The lead-calcium battery uses much less water when being charged, but
the trade off is they cannot be deeply discharged very often.

Ten deep discharges could kill one.

So if you're a shlub like me, you'd be better off with a
non-maintenance-free battery. Do they still sell those?


The deep cycle batteries are good for use in golf-carts and trolling
motors for boats. They produce a fail amount of hydrogen and would not
be a good idea to use inside one's house.


A gel cell requires very low current as it approaches full charge ,
quite a bit lower than a deep-cycle battery.


Get an "AGM" battery