question

duncanmcgill avatar image
duncanmcgill asked

Multiplus charging via smart shunt displays as discharge from battery

I can't find anyone else with this issue. It doesn't seem to affect the system, its just an oddity. as far as I can tell...

When charging my LiFePO4 battery (180Ah 12v) from the grid via MultiPlus 12/800/35-16 alongside a SmartShunt 500A/50mV my system shows the battery discharging, rather than charging (see screen print off iOS, but GX touch and browser Dashboard show the same.) . All wired up correctly and as far as I can tell the setting are all correct.


What am I doing incorrectly please??


thanks

Duncan

20230127-165919000-ios.jpg

battery chargingSmartShuntmultiplus ve.bus
20230127-165919000-ios.jpg (192.9 KiB)
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6 Answers
Alexandra avatar image
Alexandra answered ·


@duncanmcgill

It is either installed backwards (as in the shunt orientation) or the shunt is assembled incorrectly/faulty. But it is usually the orientation.

Check that the battery is on the battery side the the loads/charger are all on the side marked for loads.

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duncanmcgill avatar image
duncanmcgill answered ·

Thanks @Alexandra but It’s wired up correctly.

MPPT, DC-DC and all other loads are on the same side of the shunt and behaving as expected. Only the battery terminal is connected to the other side. Very odd

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kevgermany avatar image kevgermany ♦♦ commented ·
Please post a picture of the shunt/battery installation.

Also a screen shot like the one above, but when the system isn't charging, but has loads.


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Alexandra avatar image Alexandra ♦ commented ·

@duncanmcgill

A picture of the install would be helpful.

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duncanmcgill avatar image
duncanmcgill answered ·

It’s a Portable Power Tech Vehicle Power Hub 180Ah. I’ve modified by bypassing the built in charge controller, in preference for the Victron MPPT’s technology. Connections are Andersons: including DC-DC, MPPT, Multipoint, 12v fuse box and a spare. In addition it’s fitted with integral usb and 12v outlets. BMS is with the cells beneath a fixed panel I haven’t opened to date.

I have fitted the shunt inside the vehicle power hub, relocating links from the ground post to the shunt, then from the ‘battery’ side back to the post connected to the cells.


The vehicle power hub has a removable external isolator, together with a 120A circuit breaker internally.

The built in dc-dc & mppt unit (partially bypassed), is a Nemo DDX1230.

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duncanmcgill avatar image
duncanmcgill answered ·

I also have a Cerbo GX and Touch 50.

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kevgermany avatar image
kevgermany answered ·

As @Alexandra said, most likely cause is the shunt being wired wrongly. You haven't answered my question/posted images so we're unable to help further until you do.

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duncanmcgill avatar image
duncanmcgill answered ·


0af9e060-4890-4172-8e6e-7701c0d5db3b.pngSorry. I use my van for work and to get to the components I need to shift a lot of stuff.

As soon as I can I’ll share photos. I’m the meantime, this is my setup

b8a79022-65c8-4478-b781-425e43e5fd65.png

0af9e060-4890-4172-8e6e-7701c0d5db3b.png (324.9 KiB)
b8a79022-65c8-4478-b781-425e43e5fd65.png (302.0 KiB)
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