[GRLUG] Local APC UPS Repair

[Mark Farver]

On Tue, Apr 30, 2013 at 9:49 AM, Bob Kline <bob.kline at gmail.com> wrote:
> But as I recently learned, one has to be careful
> about the type of battery.  A deep discharge
> marine battery is made to be taken way down.

What you need is a battery capable of high current and deep cycle.
Automotive start batteries are high current, but only take a few deep
discharges before they fail and do not have much capacity.  Deep cycle
marine batteries and most RV batteries are designed for long, slow and
deep discharges, running a few lights or a small trolling motor.

What you need is a "traction" battery.  Something capable of high peak
currents, and deep discharges.  In the lead acid world these are sold
as golf cart, floor sweeper or forklift batteries.  They are almost
always "wet" cells, and as such are not ideal for indoors.  They are
also large, and heavy.  On the plus side, they are rugged, and you can
often find ones that are no longer suitable for their intended purpose
but still have plenty of capacity for your needs.  Think of a forklift
battery that no longer runs an entire shift.  (A friend once used a
2000lb used forklift battery in his garage to run his house off grid
for a week at a time.)  Unfortunately lead commodity prices have risen
a lot in the last 7 years, and lead batteries are not as cheap as they
once were.

Mark