Head scratcher - Victron Solar not charging

[Jev88]

Hi.

My solar controller can see the battery and the solar input - images below.

But two different Victrons tried and both won't charge?

New Fogstar that is currently showing 29% charged?

What am I forgetting?

 

[Mleabon]

I would go back to basics and check all your connections and fuses first. Is there an isolation switch between the solar and the mppt?

 

[Jev88]

I would go back to basics and check all your connections and fuses first. Is there an isolation switch between the solar and the mppt?

Yes a switch. But it's on.

 

[Lenny HB]

Check fogstar setting both charge and discharge need to be on.

With a new Fogstar you should charge them on mains to 100% then partly discharge and repeat 2 or 3 times before fitting.

 

[Andy MacD]

Is your Fogstar actually at 29%? Fogstar BMS notoriously unreliable.

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[Peavy]

Battery voltage and Victron voltage quite different in both screenshots. Have you checked is the same in realtime?

 

[Guigsy]

I'm not sure. But is the battery actually full? The voltage is pretty close to max for a lithium. Like Lenny said, the BMS might not be synced to the battery cells yet. Fully charge it, then run it down a bit (20% ought to do?). Next full charge it should recognise it's at max and reset the BMS to 100%.

 

[AdrianChen]

I think as a one off I would turn the chargers off, then set Absorption to 14.4v, and then turn the charger on again. Doing a one off test to see if more goes in at 14.4v will confirm if it is full since the battery should go from 14 to 14.4 on bulk pretty quickly, then return to absorption. It would also be good if you switch on Expert Mode on the settings and re-post them so we can see how the absorbtion is set up.

You mentioned two Victrons one is a 30amp Solar - What is the other? Do they have exactly the same battery settings, and are they in a Smart Network?

I does look like the BMS needs a few cycles because the battery looks pretty full....

 

[Jev88]

Check fogstar setting both charge and discharge need to be on.

With a new Fogstar you should charge them on mains to 100% then partly discharge and repeat 2 or 3 times before fitting.

Yes.... Did three cycles at home.

 

[Jev88]

Hmmmmm. Just ran a fresh cable to battery and now........ (Sun rapidly going lower )
The existing solar controller to battery cable (previous owner) disappears behind the fridge and that big American beast is staying where it is!
Guess I need to route a new cable.


P.s. Thanks all.

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[Jev88]

I think as a one off I would turn the chargers off, then set Absorption to 14.4v, and then turn the charger on again. Doing a one off test to see if more goes in at 14.4v will confirm if it is full since the battery should go from 14 to 14.4 on bulk pretty quickly, then return to absorption. It would also be good if you switch on Expert Mode on the settings and re-post them so we can see how the absorbtion is set up.

You mentioned two Victrons one is a 30amp Solar - What is the other? Do they have exactly the same battery settings, and are they in a Smart Network?

I does look like the BMS needs a few cycles because the battery looks pretty full....

Existing 100/20
New 100/30

I think it is failed cable to leisure battery from solar controller. Shame as it is routed nicely but not the cable I would have used.

 

[Jev88]

Is your Fogstar actually at 29%? Fogstar BMS notoriously unreliable.

You may be right and that could be part of it.
How to reset?

 

[fishplug]

You may be right and that could be part of it.
How to reset?

The Fogstar BMS should automatically figure out that it's at 100% after a couple of charging cycles.

They recommend using a 30-40A charger.

I know this because I only had a 10A charger with a lithium profile on it and it kept freaking out and cutting out and shutting off. It took me forever to charge the battery and the BMS was still not showing a full charge so I contacted them.

Perfectly normal for the BMS to report incorrectly for a couple of cycles apparently.

 

[Andy MacD]

Charge on mains to 100% then it will sort itself out.

Fogstar told me the BMS does not record under 1 amp, charge or discharge.

Do you have a SmartShunt? If not I’d recommend you fit one, not expensive and tells you exactly what your charge status is.

 

[fishplug]

Do you have a SmartShunt?

That's what I use to monitor the battery now as it's more reliable than the Fogstar reading.

Very pleased I got one.

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[Lenny HB]

That's what I use to monitor the battery now as it's more reliable than the Fogstar reading.

Very pleased I got one.

Check my batteries this morning both Fogstars saying 100% but Shunt says 64%. That is because the van has been sitting on the drive for over a couple of weeks with hardly any solar until the last few days. The Fogstar app is fine when the van is in daily use and it's not just Fogstar nearly all battery BMS behave this way.

 

[Just smiffy]

When you get the cable sorted and start connecting up again make sure the controller sees the battery before you connect up the solar…

 

[eddie]

Hi.

My solar controller can see the battery and the solar input - images below.

But two different Victrons tried and both won't charge?

New Fogstar that is currently showing 29% charged?

What am I forgetting?



View attachment 1021576View attachment 1021579View attachment 1021578

Is it sunny?

 

[fishplug]

it's not just Fogstar nearly all battery BMS behave this way

Yes, a valid point.

I wasn't in any way trying to put the Fogstar down.

Shunts and BMS are different things and serve different purposes.

For accurate readings of power in and power out then you really need a shunt.

Even then, some shunts are more accurate than others. My old NASA Marine one would always show 105% when fully charged and would sometimes give me readings I didn't completely trust, whereas my Victron Smart Shunt has always given me what I believe to be true readings (or as near as makes no difference)

 

[Hoovie]

Battery voltage and Victron voltage quite different in both screenshots. Have you checked is the same in realtime?

This is the key point that has been made and until that is confirmed and sorted, any other troubleshooting is redundant I would say.
There should be virtually no difference in the battery voltage and the MPPT Battery +ve.

Now last time I saw this with a Victron MPPT and Fogstar Battery, the cable was actually OK and the voltage tested at the battery terminal matched when checked with a multimeter BUT the Battery had turned off. Bit weird but it is what it is.

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