fogstar battery rcd trips

[joe9000]

Hi,before i email ben at fogstar ,just wondering if anyone has had this problem of the fogstar rack battery rcd switches off and i get a no battery error on the solis inverter,been working fantastic all summer after an update and few tweaked settings from ben then this bad weather with no sun,battery reaches forcecharge % and charges to around 30% then trips??wondering what settings on your inverters for the battery ,or any help or direction to look in as new to solar this year,thanks in advance??

 

[joe9000]

think i mightv found problem,connected to pbms tools and there was 2 cells undervoltage- unbalanced cells,percefered and got them balanced and seems to be back to normal for now!!

 

[SeaGal]

Are you sure that battery rack has an RCD? Did you mean the MCD? Even so, I don't see why that would trip, rather than just the BMS preventing further discharge.

Either way, it may be worth investigating how 2 cells became under-voltage in the first place. IMHO, the BMS should have reported low SOC way before cells became under voltage and the Solis stopped discharge... and, if they became lower still, the Solis should trigger it's force-charge mode.

What values have you got set on your Solis for over-discharge SOC and force-charge SOC?

 

[MisterB1959]

Were the cells ever top balanced before you assembled the battery? They might have been ' close' and then drifted off after time?
I thought the idea of top balancing was that you did all the cells together, how did you just top balance two of them ?

 

[joe9000]

i just let them charge and they evened out themselves,overdischarge 20 and forcecharge 18,i watched on bms tools as they came back in line but tripped again today when charging from solar when was at work!! sorry the battery has built in dc breaker which tripped,received an undervoltage battery error about 2 weeks ago when i was at work but didnt trip,i got home everything was fine and error had disapeared!!when first setup battery ben at fogstar helped with a few tweeked settings and all been fine until the past week or so,bad cloudy weather with no sun.Also appreciate any help or direction to look or settings to change,thanks.

 

[MisterB1959]

im no expert, but i understood that you need to top balance the cells before assembling the battery. from your explanation it seems as though you assembled the battery and then charged it up? is that correct or did i misunderstand you?

 

[joe9000]

sorry misterB its an already built battery from fogstar rack,i didnt assemble ,was meant to be plug and play which it was basically apart from a couple of settings,just a solar newb this year so not alot of knowledge on this!??

 

[SeaGal]

I thought the idea of top balancing was that you did all the cells together, how did you just top balance two of them ?

Bit off topic, but FYI you can always bleed off some charge of a runner using a 12V car bulb and/or charge up a lagger using an isolated bench PSU without disassembling a whole battery pack. Just need to keep a constant eye on the cell voltages with a multimeter as they can change quickly.

 

[SeaGal]

,i watched on bms tools as they came back in line but tripped again today when charging from solar when was at work

What tripped? The MCB? If so, there is another issue with too much current being passed through the MCB and not specifically related to a cell being undervoltage.

 

[MisterB1959]

sorry misterB its an already built battery from fogstar rack,i didnt assemble ,was meant to be plug and play which it was basically apart from a couple of settings,just a solar newb this year so not alot of knowledge on this!??

I'm sure a quick chat with Ben or one of the team will sort it out !! They are very helpful in my experience.

 

[joe9000]

SeaGal the battery has a dc breaker built in ,thats whats tripping,spoke to fogstar theyre going to run through a couple of things with me settings wise when i get in from work.Thanks for replys and will inform of outcome from Ben,?

 

[Pieh0]

I had an issue with the rack battery I had from Fogstar with the DC Breaker tripping. It was heating up too much past 10A and tripping.

Spoke to the guys at Fogstar and they arranged a pickup, and I upgraded to on of their kits instead, which to be fair, if I knew they were coming out with kits, I would have gone with that first, but oh well, worked out for everyone in the end .

No idea what caused it, I assume it was just a bad batch of CHINT breakers.

 

[joe9000]

Awaiting redelivery of battery as they arranged pickup the other week,says problem solved dc breaker faulty but also said not had any other dc breaker problems from theyr batterys which i dont beleive im the only one,no over heating just tripping dc breaker all the time.

 

[Pieh0]

Awaiting redelivery of battery as they arranged pickup the other week,says problem solved dc breaker faulty but also said not had any other dc breaker problems from theyr batterys which i dont beleive im the only one,no over heating just tripping dc breaker all the time.

They probably just meant that the fault you had was the only one they had. Mine was very obviously overheating, so maybe it was a wire that wasn't screwed in fully, or a different fault.

All that matters is that they stand behind their products and give support when needed, which it seems like in both our cases, they did without issue.

 

[joe9000]

received battery back and working as should for now,?