House burned down
- Thread starter Jejochen
- Start date
OffGridInTheCity
Solar Wizard
Part the issue in these discussions is extended operational time and individual experiences. I agree it's a cool discussion / thought experiment to be able to 'take a battery offline' but for me, the 1st battery was established 6years ago, have added 8 more, and haven't touched any of them once online. My experience has been that healthy batteries just don't need extraordinary on/off line capabilities if you're goal is to simply have a working powerwall.
But as I often say - no judgements. That's what DIY is all about
But as I often say - no judgements. That's what DIY is all about
Brucey
Solar Wizard
Yes there's a remote trip versions of the MNEDC175 and 250 models, RT at the end of the name, currently on sale for $107, a small difference from the regular 250A model with remote trip for $93.
MidNite Solar MNEDC250RT Remote Trip Circuit Breaker 125VDC
Shop now for MidNite Solar MNEDC250RT Circuit Breaker 250A 125VDC. Remote Trip breaker for use with our Battery Disconnect module and the Rapid Shutdown system.
www.stellavolta.com
Zwy
Emperor Of Solar
Good vendor, I bought from them before. Excellent shipping time.Yes there's a remote trip versions of the MNEDC175 and 250 models, RT at the end of the name, currently on sale for $107, a small difference from the regular 250A model with remote trip for $93.
MidNite Solar MNEDC250RT Remote Trip Circuit Breaker 125VDC
Shop now for MidNite Solar MNEDC250RT Circuit Breaker 250A 125VDC. Remote Trip breaker for use with our Battery Disconnect module and the Rapid Shutdown system.
robbob2112
Doing more research, mosty harmless
Part the issue in these discussions is extended operational time and individual experiences. I agree it's a cool discussion / thought experiment to be able to 'take a battery offline' but for me, the 1st battery was established 6years ago, have added 8 more, and haven't touched any of them once online. My experience has been that healthy batteries just don't need extraordinary on/off line capabilities if you're goal is to simply have a working powerwall.
But as I often say - no judgements. That's what DIY is all about
A few questions -
What sort of regular maintenance and inspections do you do for your battery strings?
Do you turn them all off at once or one at a time and cycle through them?
Do you have written instructions for the maint so someone else could do them if you were out of town and/or incapacitated?
Do you have documentation on your whole system design?
Do you have documentation on startup and shutdown?
Did you do a build thread?
and note - this isn't an inquesition - I am curious about how people take care of their systems once built.
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OffGridInTheCity
Solar Wizard
Up to 250 cells using longmons - https://wiki.batrium.com/en/product/cell-monitor/longmon
I can confirm that 126 work
Sounds like plan. There were ppl on youtube putting concrete floors in - anchor to ground. Make sure to get a permit if required. $50 and if put in concrete another $50 for foundation permit.
Fee grabbers.I asked this before but will mention it again for everyone was the OP shunt upgraded?
Not sure what amp those 7 strings of batteries were drawing with 3 phase 5000va 230(?) voltage inverters. I figure he is in Belgium and 3 phase charger for Tesla not available here in USA so probably 230v - my guess. Any idea what he was pulling for current? Anyone?
I think victron has a 500Amp shunt, 1000amp shunt, and a 2000amp shunt.
robbob2112
Doing more research, mosty harmless
Sounds like plan. There were ppl on youtube putting concrete floors in - anchor to ground. Make sure to get a permit if required. $50 and if put in concrete another $50 for foundation permit.
I asked this before but will mention it again for everyone was the OP shunt upgraded?
Not sure what amp those 7 strings of batteries were drawing with 3 phase 5000va 230(?) voltage inverters. I figure he is in Belgium and 3 phase charger for Tesla not available here in USA so probably 230v - my guess. Any idea what he was pulling for current? Anyone?
View attachment 214120
I think victron has a 500Amp shunt, 1000amp shunt, and a 2000amp shunt.
I don't think the op ever mentioned which size shunt he was using. I assume max expected current was 700amps, and since the OP was so meticulous with the rest of the build I assume he had a proper sized shunt.
Here in a county outside of city limits a small structure (under 120sqft) without any plumbing or electrical and lower than 18inches above ground doesn't need a permit. So the 10x10 would work fine as long as the outside diminsions are under 10x12. I am assuming it is 10x10 outside and smaller inside.
Brucey
Solar Wizard
As a very rough guess, if each inverter were maxed out at 5000VA, with the batteries at a very low 50V would be 100A each plus losses per inverter, so maybe 350A at a very worst case? But I doubt he was charging at that rate.Sounds like plan. There were ppl on youtube putting concrete floors in - anchor to ground. Make sure to get a permit if required. $50 and if put in concrete another $50 for foundation permit.
I asked this before but will mention it again for everyone was the OP shunt upgraded?
Not sure what amp those 7 strings of batteries were drawing with 3 phase 5000va 230(?) voltage inverters. I figure he is in Belgium and 3 phase charger for Tesla not available here in USA so probably 230v - my guess. Any idea what he was pulling for current? Anyone?
View attachment 214120
I think victron has a 500Amp shunt, 1000amp shunt, and a 2000amp shunt.
Brucey
Solar Wizard
Lower than 18 inches above ground?
OffGridInTheCity
Solar Wizard
Look at them now and then. After the 6+ years in mild ambient conditions I've gained enough confidence that I don't worry about them physically day by day. Monitoring (Batrium + Camera) + data history for trends is sufficient to alert me to trouble for now. Maybe after 10 more years and I start to get serious, uneven capacity degradation?
All on, all the time. Not sure why I'd want to 'cycle through them' other than some kind of individual battery capacity testing. Individual battery testing has not been needed so far... year 6+ and ongoing.
All is breaker'ed and labeled (see below). All breakers off and the system defaults to grid / becomes inactive. Order of on/off doesn't matter + individual components will shut off appropriately on their own if necessary.
Yes but the only one who's used it is me. The most useful has been the PV wiring arrangement down to the panel level.
Quick Disconnects outside at the arrays (required by code). At the control area... labeled Breakers for
- PV -> Charge Controllers (required by code - labeled with voltage/current)
- Charge Controllers -> Battery
- Battery -> Inverters.
- 400a BMS controlled shunt-trip for battery bank - shuts off 100% of all loads, no battery activity at all.
- Standard US 240v/120v distribution box / breakers.
Midnite Classic charge controllers don't care about PV vs Battery on/off order - so the overall order of turn on/off doesn't matter. All off and default is grid.
I've trained my wife/extended-family to turn all breakers off to default to grid only.
Not on this forum.
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robbob2112
Doing more research, mosty harmless
Thanks for the answers, always good to know.
Things get a little hot and the fan is needed?
Where in the picture are your fuses and shunts?
Brucey
Solar Wizard
There's no fusing in your batteries? Just the 400A shunt trip to disconnect it?
OffGridInTheCity
Solar Wizard
It's 18650 - and each of the 12,000+ individual cells are connected to the buss with fuse wire (based on Tesla car battery design). Thus, don't need fusing at the pack or battery level the way one might want for LifePo4 cells.
If a short were to occur, it's not clear weather the ABB SACE would trip or fuse wires would blow first or both - the entire powerwall would be rendered toothless in short order. It would be a huge 'rebuild' effort
The ABB SACE could trip at 400a overall load (or charge) but the powerwall itself has ~2,000a @ 48v potential so the fuse wire won't burn just for a 400a load. It would take short at a pack or battery or powerwall level for the fuse wires to burn - but that's what they're for.
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Brucey
Solar Wizard
Ok, I understand now, each cell is fused so no worries at all there for a runaway situation like the OP had.It's 18650 - and each of the 12,000+ individual cells are connected to the buss with fuse wire (based on Tesla car battery design). Thus, don't need fusing at the pack or battery level the way one might want for LifePo4 cells.
If a short were to occur, it's not clear weather the ABB SACE would trip or fuse wires would blow first or both - the entire powerwall would be rendered toothless in short order. It would be a huge 'rebuild' effort
The ABB SACE could trip at 400a overall load (or charge) but the powerwall itself has ~2,000a @ 48v potential so the fuse wire won't burn just for a 400a load. It would take short at a pack or battery or powerwall level for the fuse wires to burn - but that's what they're for.
Certainly puts the fear of god into you when you read something like this. Thankfully he and his family are safe but almost certainly a life changing event. I read about an electronic engineer who had setup lifepo4 batteries from china in germany and house also destroyed but from an explosion.
www.pv-magazine.com
I think ill start planning to move all my kit out to the shed.
Investigators still uncertain about cause of 30 kWh battery explosion in Germany
A lithium iron phosphate (LFP) battery system recently exploded in a home in central Germany, preventing police and insurance investigators from entering due to the high risk of collapse. The explosion may have been preceded by off-gassing, but it remains unclear whether an external ignition...
www.pv-magazine.com
I think ill start planning to move all my kit out to the shed.
robbob2112
Doing more research, mosty harmless
Certainly puts the fear of god into you when you read something like this. Thankfully he and his family are safe but almost certainly a life changing event. I read about an electronic engineer who had setup lifepo4 batteries from china in germany and house also destroyed but from an explosion.
Investigators still uncertain about cause of 30 kWh battery explosion in Germany
A lithium iron phosphate (LFP) battery system recently exploded in a home in central Germany, preventing police and insurance investigators from entering due to the high risk of collapse. The explosion may have been preceded by off-gassing, but it remains unclear whether an external ignition...
I think ill start planning to move all my kit out to the shed.
Make the shed fireproof first
Brucey
Solar Wizard
I think the speculation was that the boiler pilot light may have have ignited the outgassing hydrogen from the cell(s).Certainly puts the fear of god into you when you read something like this. Thankfully he and his family are safe but almost certainly a life changing event. I read about an electronic engineer who had setup lifepo4 batteries from china in germany and house also destroyed but from an explosion.
Investigators still uncertain about cause of 30 kWh battery explosion in Germany
A lithium iron phosphate (LFP) battery system recently exploded in a home in central Germany, preventing police and insurance investigators from entering due to the high risk of collapse. The explosion may have been preceded by off-gassing, but it remains unclear whether an external ignition...
I think ill start planning to move all my kit out to the shed.
Zwy
Emperor Of Solar
Those were pouch cells.
_voltmeter_
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