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solar-mann avatar image
solar-mann asked

Bluetooth Dongle voltage not reporting correctly

I have a bluetooth smart dongle connected to a MultiplusII inverter. It is reporting about .5-.6 volts higher than actual battery voltage. I have confirmed with multiple meters (that are used daily and correct), it is not a voltage loss or connection issue. I have spoken to battleborn batteries (who i purchased through), they said they and victron are both aware of this issue on a batch of the dongles and that a firmware issue would be released to fix the issue. That was months ago and still no update or fix that i am aware of. Anyone have any information?

Bluetooth
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3 Answers
solar-mann avatar image
solar-mann answered ·

Last update on this matter, finally got ahold of battleborn again and they decided to send me a new dongle. plugged it in and this one works perfectly.

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Alexandra avatar image Alexandra ♦ commented ·
@Solar_Mann

Neat glad there was a resolution to the issue.

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Alexandra avatar image
Alexandra answered ·

@Solar_Mann

Maybe a few more specifics about your system? The BT dongle is only reporting what the inveter is reading at its terminals. Are you connected to grid at the time? Maybe there is a potential created by the ac charger. Or your cable length or diamater is creating the issue?

I have a multi compact 12v 1600va with BT dongle and bmv with Blue Nova batteries and dont have the issue. My system is mobile right now.

My BT dongle is currently reporting 13.6v and the BMV 13.56v

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solar-mann avatar image solar-mann commented ·
It’s a mobile/RV system. I’ve verified it’s not a cable/resistance problem. Dongle reads high during heavy charge and heavy discharge. Ive installed a few of these over the years, this is the first one to have an issue.
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Alexandra avatar image Alexandra ♦ solar-mann commented ·
What I am saying is voltage will be higher at the multi terminals during charging especially at higher currents, this is expected.


If it is higher at the multi when there is a heavy discharge and it is offgrid that would be unexpected.


Does it read the same when idle?



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solar-mann avatar image solar-mann Alexandra ♦ commented ·
Sorry, the reply function wasn't working correctly on my phone. My reply is below.


Thank you!

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Matthias Lange - DE avatar image Matthias Lange - DE ♦ solar-mann commented ·
If you think the Smart dongle is defective you should contact the seller from whom you bought it. He can check it and send you a new unit.
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solar-mann avatar image solar-mann Matthias Lange - DE ♦ commented ·

during the initial talk with them (Battleborn batteries) they said the replacements had the same issue. They have since stopped replying to me, I guess I’ll have to blow them up tomorrow and try to get a replacement or at least an update from them.

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solar-mann answered ·

it reads high under all conditions. Charging, discharging and idle all show about .5v higher than actual voltage. it has been sitting idle (no charge, no grid) for 2 weeks and still shows 13.75v, actual voltage is 13.22.


if i unplug the dongle and plug my laptop into the multiplusII the voltage is shown correctly. issue is the dongle.

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Alexandra avatar image Alexandra ♦ commented ·

Where is the dongle connected? At the batteries or the multi?

I did see when I moved it around the system and if I stacked them and how I stacked it on terminals with other items affected its readings. Especially during high charges and discharges.

difference was .02 though in an overload condition between the dongle report and take off point with the Fluke.

So comparing to the bmv reading that is not at the same point on the system (shown on the GX) there is a just under 0.2V difference. For me that 0.2v is quite acceptable as most batteries the range of charge voltages is about 0.2 to 0.3v anyway.

img-20220124-183424.jpg

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solar-mann avatar image solar-mann Alexandra ♦ commented ·
Was originally hooked directly to the battery bank but I have moved it to the studs on the inverter for better packaging. No difference in either location.
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