This is a question about a Mas Tech power supply (which looks like most of the inexpensive single-output power supplies from China these days) and its shutdown circuit: When I connect to a 33AH disability scooter battery pack with approx. 25.2v the Mas Tech won't dial higher than 25.4v until the supply has had about 5+ hours of non-use.
The lock-down is immediate, but I sometimes, the supply works, and I'm able to charge the battery pack.
Doesn't seem to make any difference if I connect the load first, then turn it on, or vice versa. It is very baffling.
This is a new model, with auto-switching 115v-230v AC, no fuses from the outside.
All suggestions appreciated.
FYI it seems to be well protected from reverse polarity -- didn't get damaged from reverse currect high enough to weld connectors!