I acquired a marine battery charger/conditioner (Promativ 40-3). I
just tried it on the battery from a lawnmower which at first showed
less than 7 volts (12V battery). My car battery 10 amp charger could
barely get any current into the battery (barely moved the meter).
Leaving the battery on the new charger overnight seems to have
restored its ability to hold 12V.

What I am wondering is, would it be reasonable to use this charger
(It's rated for 40 amps) to charge smaller batteries like the 5 amp
hour gel cells from a UPS? I would think that it is regulating for
voltage, and monitoring the battery voltage to determine when to
reduce the charging voltage. I have a number of these batteries which
I'd love to restore to semi usable condition. Is it reasonable to use
this charger on them?

Bob

"Bob F" wrote in message
. ..
I acquired a marine battery charger/conditioner (Promativ 40-3). I just
tried it on the battery from a lawnmower which at first showed less than 7
volts (12V battery). My car battery 10 amp charger could barely get any
current into the battery (barely moved the meter). Leaving the battery on
the new charger overnight seems to have restored its ability to hold 12V.

What I am wondering is, would it be reasonable to use this charger (It's
rated for 40 amps) to charge smaller batteries like the 5 amp hour gel
cells from a UPS? I would think that it is regulating for voltage, and
monitoring the battery voltage to determine when to reduce the charging
voltage. I have a number of these batteries which I'd love to restore to
semi usable condition. Is it reasonable to use this charger on them?

If they need restoring, you have nothing to lose. I haven't done it, but I
think you're probably on safe ground since lead-acid battery charging is a
matter of regulating voltage rather than current. How does the restorer
work?

"mc" wrote in message
...
"Bob F" wrote in message
. ..
I acquired a marine battery charger/conditioner (Promativ 40-3). I
just tried it on the battery from a lawnmower which at first showed
less than 7 volts (12V battery). My car battery 10 amp charger could
barely get any current into the battery (barely moved the meter).
Leaving the battery on the new charger overnight seems to have
restored its ability to hold 12V.

What I am wondering is, would it be reasonable to use this charger
(It's rated for 40 amps) to charge smaller batteries like the 5 amp
hour gel cells from a UPS? I would think that it is regulating for
voltage, and monitoring the battery voltage to determine when to
reduce the charging voltage. I have a number of these batteries
which I'd love to restore to semi usable condition. Is it
reasonable to use this charger on them?

If they need restoring, you have nothing to lose. I haven't done
it, but I think you're probably on safe ground since lead-acid
battery charging is a matter of regulating voltage rather than
current. How does the restorer work?

The best I can find suggests that it applies full current until it
reaches 14.6 volts. It then hold 14.6 for 1-4 hours. After that it
reduces to 13.3 volts from then on.

The model, by the was is promatic 40-3, not promativ.

Bob