question

njhelspe avatar image
njhelspe asked

Seems like Multiplus has an internal short?

Hi,

I have a Multiplus 24v/3000va/70amp. When I connect the 24volt battery, the battery voltage goes to 6volts or less. It seems like the multiplus is shorting the battery. The Multiplus flashes the low battery light, then briefly flashes the overload light before doing nothing. Both units that I have do the same thing.

When i remove the Multiplus units from the circuit, the mppt smart solar chargers work fine and the battery voltage stays at 28volts. I checked my circuit many times and it seems correct.

I am setting up my system for the first time and could be doing something wrong.

Any help that you can provide would be appreciated.

Thanks,

-Nick

MultiPlus Quattro Inverter Charger
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5 Answers
klim8skeptic avatar image
klim8skeptic answered ·

Sound like the multiplus is tripping the Battleborn BMS.

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njhelspe answered ·

Thanks, @klim8skeptic. You were exactly right! Once I precharged the Multiplus capacitors the system worked fine. I was only using 2 of my battle born batteries in series for this initial test. Likely when I hookup the others in series, I won't have this problem anymore because the outrush current on each battery will be much lower. Thanks again!

-Nick

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njhelspe answered ·

Yes, I was able to finally configure the battery settings in the Multiplus. Originally, it was going to be a challenge to program it because I couldn't power the Multiplus as the Battle born batteries were shutting down due to the high current outrush needed to charge the Multiplus' capacitors. They have an onboard battery monitoring system that shuts off the battery if it thinks there is a short. I was able to charge the Multiplus Capacitors using a light bulb in series with the batteries. Then I was able to power on the Multiplus and perform the battery programming.

Thanks!

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njhelspe answered ·

One other comment. I am using Battle born batteries. The battery voltage is about 27.7volts currently. Is it possible that the Multiplus thinks the voltage is too high and is shutting off? I put a light blub between the + side of the battery and the + side of the Multiplus. Setting the Multiplus to charge only makes a clicking noise and I watch my multimeter's voltage across the light bulb start going up until about 25volts or so then I hear another clicking noise and the voltage slowly starts bleeding down to zero.

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kevgermany answered ·

Did you configure the battery settings in the multiplus?

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