On 14 Mar 2004 07:48:12 -0800, N. Thornton wrote:

IIUC SLAs are only finicky about overvoltage charging, and putting a
bigger battery on wont cause that.

They really like three stage charging, but I get the feeling that you
already know this but for the benefit of the group. Stage 1 constant
current "boost" at some fraction of the capacityA. Then as the cell
voltage rises switch to constant voltage (approx 2.4v/cell) the charge
current the slowly falls as the charge is "topped up". Finally at as
the cell voltage increases further switch to constant voltage of
approx 2.25v/cell and low current to keep the battery float charged
and counter self discharge.

The actual switching voltages and float voltage vary a bit depending
on the useage of the battery, standby, regular deep discharge etc.

Would the charger in a UPS expecting a certain capacity of battery,
the one it was designed for and thus could do the switching based on
time rather than cell voltage. Thus a bigger capacity battery would
never be fully charged...

I used to have car battery based backup, but after a while
switched to gas.

Fuel cells? Now that is expensive. B-)

heh.

Electricity from gas... oh never mind.

Until it goes dark... Example: Power goes at 1400 (for our normal
6hrs), daylight goes at 1700, when are the emergency lights going
to go off with flat batteries? When do you really need the light?

You can add that feature if you want. If not, youll get so many
hours of power cut covered and no more.

I'd like the light when I need it, automatically, when it's dark. I
don't know of any non-maintained emergency lights that have a photo
sensor to keep 'em off it it's "light".

--
Cheers
Dave. pam is missing e-mail