Issues with new solar power system on motorhome

[rls106]

Hi, I have recently had a new 300w solar power system fitted to my motorhome controlled by a Victron 100/30 MPPT. I also had a 110ah lithium battery fitted at same time.
For about 4 weeks (good sunlight ) worked well. I am currently on a c&CC site for ten days (little sunlight). First day and night tv and lights worked fine but night before last at 10.15pm all power stopped. The following morning around 7.30am started again although Victron app showed battery voltage at 8.9 v. This climbed during the day to 11.9v with tv and lights working. At about 7.30pm last night tv wouldn’t come on and no power to charging sockets. Lights stayed on for about 10 minutes and then went off.
So far this morning no power. Victron app can’t be accessed as seems to be powered off.
Is this normal? I was led to believe by installer that even on cloudy days system would produce sufficient charge to last for days.
Any help appreciated.

 

[rls106]

Update at 07.47am Power just come back on. Voltage on app showing 11.7v

 

[Diabalo]

First I think you need to get on EHU and give the batteries a good charge. Can you see on the app what voltage you have coming into the controller from the panels?

 

[Ditcha]

Sounds like your using more than you are putting in.

 

[rls106]

8.00am no appliances or even lights being used but battery voltage dropped to 8.0 v and keeps turning itself on and off!

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[Lenny HB]

The BMS in the lithium should have shut down at 10.5v, absolute minium you should take lithium down to is 10v, 2.5v per cell.
If it went down to 8.9v it's probably had it.

 

[rls106]

First I think you need to get on EHU and give the batteries a good charge. Can you see on the app what voltage you have coming into the controller from the panels?

Yes the Victron app shows around 15 volts coming in but changing constantly between 14v and 57v. I’m not using any power at all other than the Victron controller and green light on control panel which keeps changing from on to off. Current battery voltage showing as 11.4v but in last half hour has been as low as < 8v.

 

[Ditcha]

What make of battery do you have and can you take a screenshot of the victron connect app showing your mppt data.

 

[WillysMB]

we have 300 ( or was that 320w) solar and a 220 of lithium and we have been using 15% or so of battery every night ..
so it does seem like you may have an issue ...i'm with Diablo in that it will give your battery a really good charge and that you
at least have a good base to measure from.
I can monitor our battery via an app and of course the the app for the solar charger so know what we are generating on a daily basis.
like you we are suffering horrible grey Skys.

 

[rls106]

What make of battery do you have and can you take a screenshot of the victron connect app showing your mppt data.

The battery is EcoTree Lithium. A couple of screenshots attached. Seems to have settled somewhat. It did similar yesterday though and went off 7.30pm.

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[rls106]

we have 300 ( or was that 320w) solar and a 220 of lithium and we have been using 15% or so of battery every night ..
so it does seem like you may have an issue ...i'm with Diablo in that it will give your battery a really good charge and that you
at least have a good base to measure from.
I can monitor our battery via an app and of course the the app for the solar charger so know what we are generating on a daily basis.
like you we are suffering horrible grey Skys.

Grey skies indeed, washed with buckets of rain.

 

[Diabalo]

So starting on the 15th Oct your battery has not fully charged on each subsequent day, your taking out more than the solar can top up. You wont get fully charged without getting on EHU.

 

[monzer]

Can I ask if your new battery was a replacement or was it added to an existing battery? Was it fully charged after fitting? Your Victron MPPT should be showing a light, maybe flashing quickly or maybe quite slowly, what is it showing?

 

[MisterB]

I was led to believe by installer that even on cloudy days system would produce sufficient charge to last for days.
Any help appreciated.

the charge does last for days, so long as you dont actually use your battery ......

and thats one of the things you need to identify, how much power are you taking from your battery and how much power youre putting back in .... and of course what was your starting point?

as an example we have a 304Ah lithium with 200w of solar, we can easily consume 15-20% of battery using 240v appliances via an inverter. the 200w solar is not enough to totally replenish what we use (even when we were overseas in very good weather). i reckon we could go 4 days max in the UK by just using whatever we wanted, whenever we wanted, without moving in the winter months, relying purely on battery and solar.

perhaps a bigger battery or yours being fully charged every 2 or 3 days will help you get round the issue? which means either charging from the mains or topping up via driving for a few hours as you move around (if thats your modus operandi)

 

[treblid]

The second screenshot shows you have 34V coming off the solar. The MPPT solar controller should be putting in much more than 0.2A into a battery that is under 12V.

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[Ditcha]

So starting on the 15th Oct your battery has not fully charged on each subsequent day, your taking out more than the solar can top up. You wont get fully charged without getting on EHU.

Agree the last time the battery was full was the 14th showing absorption then float. Don't think you have any problems with the solar so it's down to battery and settings but I think your using more than your putting in have you a screenshot of the battery app do you have a shunt? Battery app could be give false state of charge as they are not very accurate.

 

[Ditcha]

The second screenshot shows you have 34V coming off the solar. The MPPT solar controller should be putting in much more than 0.1A into a battery that is under 12V.

Depends on how the panels are wired.

 

[rls106]

All I have been us

the charge does last for days, so long as you dont actually use your battery ......

and thats one of the things you need to identify, how much power are you taking from your battery and how much power youre putting back in .... and of course what was your starting point?

as an example we have a 304Ah lithium with 200w of solar, we can easily consume 15-20% of battery using 240v appliances via an inverter. the 200w solar is not enough to totally replenish what we use (even when we were overseas in very good weather). i reckon we could go 4 days max in the UK by just using whatever we wanted, whenever we wanted, without moving in the winter months, relying purely on battery and solar.

perhaps a bigger battery or yours being fully charged every 2 or 3 days will help you get round the issue? which means either charging from the mains or topping up via driving for a few hours as you move around (if thats your modus operandi)

All I have been using is two LED lights (no more than two hours over five days), 12v tv initially about 4 hours each day but not been able to use due to lack of power for last three days, plus a usb socket for charging iPad and phone. The entire system is new including battery, solar panels and tv.

 

[rls106]

If I can get onto a EHU pitch would that charge the battery back to full power and is it safe to do this?

 

[MisterB]

All I have been us

All I have been using is two LED lights (no more than two hours over five days), 12v tv initially about 4 hours each day but not been able to use due to lack of power for last three days, plus a usb socket for charging iPad and phone. The entire system is new including battery, solar panels and tv.

i feel your pain, you will have spent a lot of money having what you were told will work installed!

do you know what your battery level was when you pitched up? as previously suggested by a couple of people, your battery may not have been fully charged before hand.

re the charge from EHU, there is no reason why not, especially as the installation is new and would have been checked ?? we sometimes do exactly the same thing, one night/day on ehu fully charges our battery (or close to it)


based on your use of battery, i would have thought you could easily do a week off a fully charged battery !

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[rls106]

i feel your pain, you will have spent a lot of money having what you were told will work installed!

do you know what your battery level was when you pitched up? as previously suggested by a couple of people, your battery may not have been fully charged before hand.

based on your use of battery, i would have thought you could easily do a week off a fully charged battery !

That’s pretty much what installer told me. I don’t have a lot of confidence in him though based on other jobs he did at same time. Hoping for gap in rain to go and see if I can switch to a pitch with EHU.

 

[StillGoing]

If the BMS has allowed the voltage to drop below 10.5V I’d be going back to the supplier and asking for a refund as the BMS hasn’t done its job.

Get a Fogstar battery - it’s cheaper, has a heater and Bluetooth so you can see what the BMS settings are.

 

[funflair]

The second screenshot shows you have 34V coming off the solar. The MPPT solar controller should be putting in much more than 0.2A into a battery that is under 12V.

Not at 08:15 on a grey day with only 4w on the panels though, voltage is no indication of potential power output.

 

[68c]

Do you have a compressor fridge?

 

[Diabalo]

If I can get onto a EHU pitch would that charge the battery back to full power and is it safe to do this?

It should be ok if the installer has done their job correctly, have you had it on EHU since the install if so did it fully charge then?

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[treblid]

Not at 08:15 on a grey day with only 4w on the panels though, voltage is no indication of potential power output.

The 4W is only being produced because that is all that is being drawn.

A Victron MPPT will start harvesting power when the solar is 3 to 4V above the battery. If the solar can't deliver, the panel voltage will be pulled down to this minimum voltage.

 

[autorouter]

The following morning around 7.30am started again although Victron app showed battery voltage at 8.9 v.

I note that it's the Victron app that's showing 8.9V, not the BMS or the Ecotree app. So maybe the BMS has shut off the battery, and the Victron app, now disconnected, is showing some random voltage which is not the actual battery voltage at all.

If you get onto an EHU pitch that will get you back to 100% after a few hours. Then you can disconnect the EHU and try taking power from the battery, and watching to see if the solar is putting any power into the battery.

 

[funflair]

The 4W is only being produced because that is all that is being drawn.

A Victron MPPT will start harvesting power when the solar is 3 to 4V above the battery. If the solar can't deliver, the panel voltage will be pulled down to this minimum voltage.

You could only say that if you knew that the solar conditions were capable of more than 4W, my money is on "it's a grey day and that's all it will produce".

 

[treblid]

You could only say that if you knew that the solar conditions were capable of more than 4W, my money is on "it's a grey day and that's all it will produce".

In that scenario, I would expect to see 16 to 17V on the solar panel if the battery is at around 12V with the 0.2A charge.

 

[rls106]

I have moved to a pitch with EHU but still getting only power for lights both on 12v and with EHU PLUGGED IN. No power at any sockets.