Hi again,

I let the battery charge all last night and all day until just a few
minutes ago, it was charging at 13.8 volts. With a 25watt soldering
iron plugged into it the lowest I could get the battery to drop was 12.2
volts. I plugged my 100/140watt soldering gun into it and put it on
100watts, within about a second the voltage plummeted at 10.something
volts and then the unit shut itself down.

I let it charge again up to 13 volts, as soon as I put it on 140watts
the unit instantly shut down. On 100 watts the draw is slow enough to
notice that the voltage plummets to 10.6 volts in about 3 seconds, then
it shuts down.

This is almost the identical test that is done on car batteries, they
are supposed to stay above 10.5 volts for so many seconds, if they drop
below 10.5 too soon that battery is considered bad and in need of
replacement which is what I will be doing with this thing.

Thanks for your help, I never would have suspected the battery.


-Landon

loedown wrote:
Measure the battery's voltage when the unit is on load, not when it is out
of circuit, not when it is charging or at any other time, this is the only
way you will see if it is truly the battery. Even if this isn't possible,
get a 12V filament lamp and connect that to the battery out of circuit and
monitor the voltage. Without doing these things, you are just compounding
the issue and not determining whether the battery is at fault, or the unit
itself.

SLA charging voltage should be around 13.8 V

Paul