looking for a very technical answer Re: Batteries

[Anonymous user]

recently acquired a bk300c. In testing it out i ran into some interesting things.
1. replacing the battery with a DC power supply the unit would not function. (no output from inverter)
2. with the battery in place and the power supply attached in parallel it would function, but strangely at a reduced output voltage..if the PS voltage was reduced (below that of the battery) the output voltage would climb! reaching its max(108v) when the PS was disconnected completely.

it appears that the battery is somehow doing more than providing power.

can anyone explain these? I'd love to get a schematic if there are any floating around out there. or a good technical description of what is going on in there!

Thanks!!
rtv

[upsguy_apc · Accepted solution]

You are paralleling two power supplies that are not meant to perform this way.

Charger circuit 1X power supply

And your DC power supply other.

Your lucky you didn't break your UPS or blow internal fuses.

UPS's have there own charging circuits and don't require external inputs. They are not designed to operate this way so don't do it.