Troubleshooting My System.

[Dafishydude]

Hey All,
I have an off grid system that has been performing swimmingly for the last 3 plus years. This last week I got home and everything was off. We had a LOT of cloudy weather so I wasn’t sure if it just needed a big old charge but there are some weird readouts on my Victron controller so it’s definitely more than that. I also watched it a lot today as it was a full sunny day today. I attached some screenshots of the victron trends as well as what was coming in off the panels. There was no more than half an amp coming off the panels today even in full sun which was very weird. I plugged in my little cell monitor and the battery seems to be decently charged at 26.68 volts. All the cells are at 3.3 volts but there is some variation the lowest being 3.31 and the highest being 3.34. I can’t remember what tolerances are OK. The trend says the battery got down to single digit volts which would mean my battery was toasted? Or is something else going on?
When the sun got off the panels I tried running my bathroom light and fan and the inverter was beeping and going on and off but my battery voltage on the little voltage reader remained steady. Is my inverter broken? There seems to be quite a few weird things happening and given that I am an amateur I would appreciate any insight as well as advice on how to go about narrowing down the issue/issues. Thanks for your help!

 

[tom roberts]

Hey All,
I have an off grid system that has been performing swimmingly for the last 3 plus years. This last week I got home and everything was off. We had a LOT of cloudy weather so I wasn’t sure if it just needed a big old charge but there are some weird readouts on my Victron controller so it’s definitely more than that. I also watched it a lot today as it was a full sunny day today. I attached some screenshots of the victron trends as well as what was coming in off the panels. There was no more than half an amp coming off the panels today even in full sun which was very weird. I plugged in my little cell monitor and the battery seems to be decently charged at 26.68 volts. All the cells are at 3.3 volts but there is some variation the lowest being 3.31 and the highest being 3.34. I can’t remember what tolerances are OK. The trend says the battery got down to single digit volts which would mean my battery was toasted? Or is something else going on?
When the sun got off the panels I tried running my bathroom light and fan and the inverter was beeping and going on and off but my battery voltage on the little voltage reader remained steady. Is my inverter broken? There seems to be quite a few weird things happening and given that I am an amateur I would appreciate any insight as well as advice on how to go about narrowing down the issue/issues. Thanks for your help!

 

[Rocketman]

I think the bms has tripped or died in the battery. Or somehow the battery is no longer really connected to everything else.( Fuse, loose wire, etc) My guess is all the voltage around 26v is just being produced by the SCC as it is consumed.

What batteries do you have?
(Actually list all your equipment). Do you have a shunt? Smartshunt or BMV712?

One test: during the day - when solar is going the little it goes- turn off the mppt (there is a setting for that in the app) and then what happens?

 

[tom roberts]

I have the same problem. My panels are putting out 40V but with no amps. I have a one year old Xantrex 3024 inverter; brand new T105 batteries (20); older Apollo Solar T80 charge controller (company no longer in business); and an older wind generator. My batteries are not getting or holding a charge. My first thought was that the controller was going bad but I swapped out an older PWM controller but same results. I checked every connection but nothing helped. The inverter seems to be working fine. If I run the generator, the inverter clicks over to charge and run the house. Sure hope someone will have some suggestions for us. Goodluck. Tom.

 

[tom roberts]

I think the bms has tripped or died in the battery. Or somehow the battery is no longer really connected to everything else.( Fuse, loose wire, etc) My guess is all the voltage around 26v is just being produced by the SCC as it is consumed.

What batteries do you have?
(Actually list all your equipment). Do you have a shunt? Smartshunt or BMV712?

One test: during the day - when solar is going the little it goes- turn off the mppt (there is a setting for that in the app) and then what happens?

BMS????

 

[Dafishydude]

I think the bms has tripped or died in the battery. Or somehow the battery is no longer really connected to everything else.( Fuse, loose wire, etc) My guess is all the voltage around 26v is just being produced by the SCC as it is consumed.

What batteries do you have?
(Actually list all your equipment). Do you have a shunt? Smartshunt or BMV712?

One test: during the day - when solar is going the little it goes- turn off the mppt (there is a setting for that in the app) and then what happens?

The system is 4- 340 watt panels. They come into a victron SCC and then they are sent to the battery. The battery has a Daly BMS on it. The inverter is a 2000 watt inverter. Here is some video of the cell monitor and the inverter.

 

[Rocketman]

Yea, your battery doesn’t look like it is full. My guess is about half full - based on voltage- which is a totally lousy way to tell SOC of lithiums.

With the solar off - do you have any voltage- use a digital multimeter.
Does it agree with the BMS?
Does it agree with the solar charge controller’s battery voltage as stated in the app?

My guess is the BMS or something else in the battery is not letting power through (fuse, lose connection, etc). My reasoning is you are not charging (from the SCC) and you are not discharging from the inverter.

What battery do you have - a DIY one? what size in ah? Which bms? What is the different ratings on the bms?

 

[Dafishydude]

Yea, your battery doesn’t look like it is full. My guess is about half full - based on voltage- which is a totally lousy way to tell SOC of lithiums.

With the solar off - do you have any voltage- use a digital multimeter.
Does it agree with the BMS?
Does it agree with the solar charge controller’s battery voltage as stated in the app?

My guess is the BMS or something else in the battery is not letting power through (fuse, lose connection, etc). My reasoning is you are not charging (from the SCC) and you are not discharging from the inverter.

What battery do you have - a DIY one? what size in ah? Which bms? What is the different ratings on the bms?

I will test some of this today. I did notice yesterday that if I switched off the scc the inverter would freak out and die, showing it wasn’t getting power. Which I thought was weird given that the battery should have had enough juice to run Stuff normally. So you are right that there seems to be some connection issue. The battery is 24 volt 280 ah. It is a DIY battery. It has a DALY BMS on it that I bought from eBay. I can’t remember the specifics but can find out. Honestly not really sure how to test the BMS and make sure everything is working right on that part. When I look at cell voltage separate from the scc it looks like the battery still has voltage. According to the scc: it appears that the battery drop like crazy when sun is not shining and there is very little charging happening from scc to battery. Could the scc be supplying power to the inverter but skipping the battery? Thanks for your help!

 

[Rocketman]

if you check all the connections on the battery, and they look good - My GUESS. is the bms may be dead - or somehow a setting got changed in the bms.

Unfortunately, I don’t know much about the Daly bms’s - except they don’t seem to have a good reputation on this site.

A couple of years ago a DIY-ed a small 50ah portable battery and put an overkill bms in it. I think JDB makes it.

Good Luck

 

[Dafishydude]

if you check all the connections on the battery, and they look good - My GUESS. is the bms may be dead - or somehow a setting got changed in the bms.

Unfortunately, I don’t know much about the Daly bms’s - except they don’t seem to have a good reputation on this site.

A couple of years ago a DIY-ed a small 50ah portable battery and put an overkill bms in it. I think JDB makes it.

Good Luck

Ok so I did some more tinkering and I think you are right. The BMS is messing up. When I look at battery voltage it is all good but the BMS output negative with the battery positive is like 3 volts. This means that the battery isn’t able to send its voltage to the inverter and it’s not able to receive power from the scc. I think these Daly BMS are not great. Do you have a recommendation for a replacement BMS? Preferable somewhere in USA so I can get it more quickly? I require a 24 volt 300 amp BMS. I actually see the JBD BMS that comes from Chicago and am thinking about pulling the trigger on that one. How has your experience been? Also thanks so much for your help!

 

[Dafishydude]

if you check all the connections on the battery, and they look good - My GUESS. is the bms may be dead - or somehow a setting got changed in the bms.

Unfortunately, I don’t know much about the Daly bms’s - except they don’t seem to have a good reputation on this site.

A couple of years ago a DIY-ed a small 50ah portable battery and put an overkill bms in it. I think JDB makes it.

Good Luck

My other question: on advanced SCC like Victron it will just cut amperage if there is not a solid connection to the battery?

 

[Rocketman]

My other question: on advanced SCC like Victron it will just cut amperage if there is not a solid connection to the battery?

The Victron SCC (once the voltage is set), will act as a battery charger. So if the battery gets disconnected, then it will just try to run the loads - which is what I believe has been happening to you - if your load is less than what the mppt can supply - then it will supply it all just right.

I think of it way- The loads pull amps. As long as the supply can provide that level of amps - everything is happy.

As for the bms - I got mine from Overkill - but I have not been paying attention to what is out there now.