Topic: SLA consumption calculation

[it-goes-to-eleven]

I've been doing a little SLA (spinal location adjustment) rig powering recently.  I'd like to figure out whether I can go down in battery size.

For the Moe show, my 12AH AGM had an initial voltage of 13.18 volts.  Ending voltage was 12.75. That was after 174 minutes of recording. I figure it includes an additional 10 or so minutes of run time. I think the exeltech may have been connected to the bat during intermission, so there was probably some drain there as well.

Based on that, I'm thinking it should be possible to calculate my amphour/hour requirement and determine whether I could go smaller on the bat.

Any tips would be appreciated.  Thanks!

[Brian Skalinder]

This oughta give you a ballpark idea of run-time, assuming you know the current draw for your gear:

http://taperssection.com/index.php?topic=2460.0

[it-goes-to-eleven]

Thanks Brian.  I'm fine with the basic estimates.. I'm hoping for a way to confirm the real world rate based on the actual field data.

[Brian Skalinder]

I'm hoping for a way to confirm the real world rate based on the actual field data.

IMO, the only way to do that is to actually run the gear and time it.  Anything else - even calculations based on field data - would still be an estimate.

[anhisr]

That is how I did it.  Set up the rig downstairs and turned on the speakers and let it go.  Now since I had to turn the V3 all the way up that I am sure sucked down more juice but, it gave me a better guess. YMMV

[pigiron]

FWIW... I got a cheap DVM from rat shack that measures amps... started at the 10A setting and put it in series with the battery connector...

then tried to average the bouncing digits