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Re: Yet another DIY LF280K Storage Battery
My rule of thumb is if its too hot to touch or hold, its too hot.
16.9kW PV > 109MWh generated
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Ripple 6.6kW Wind + 4.5kW PV > 25MWh generated
5 Other RE Coop's
105kWh EV storage
60kWh Home battery storage
40kWh Thermal storage
GSHP + A2A HP's
Rain water use > 510 m3
Re: Yet another DIY LF280K Storage Battery
It's for fault tolerance not regular operation.
By 2 units I mean compared to the regular A spec of 4 AWG @70A 60C.
Pylontech recommend banks of 4 to busbar, practically doesn't matter as the BMS is captain of the charge current.
Amazing how good these cells are!
By 2 units I mean compared to the regular A spec of 4 AWG @70A 60C.
Pylontech recommend banks of 4 to busbar, practically doesn't matter as the BMS is captain of the charge current.
Amazing how good these cells are!
Re: Yet another DIY LF280K Storage Battery
Just seen this on another forum that I thought was worth reposting here.Joeboy wrote: ↑Tue Jan 17, 2023 12:47 pm9 degs is as low as I have seen displayed on my bms software and that's with minus 12 outsidemarshman wrote: ↑Tue Jan 17, 2023 12:28 pm Spot on Nowty. I don't think there is any concern about temperature rise due to high rate discharge or charging. The issue is low temperature charging. I am in the soft south "desert" where temps usually only dip below zero over night when the batteries are usually charging so not an issue for me. BUT up t'north it may become an issue if the batteries are in an uninsulated outbuilding.
This is from the EVE datasheet and specifies charging rates for various temperatures:
Its actually a bit lower than I would have expected. So for a single set of cells in series (280Ah) at 10c you need to be careful that you don't exceed 56A charging at the top end of SOC, which is actually pretty close to what a lot of us are doing with 70A chargers or so.
Just worth noting I think that its not as simple as being able to stuff 1C into these if you're above freezing; it tapers off quite significantly.
Re: Yet another DIY LF280K Storage Battery
That's definitely worth noting for those that have went full EVE and removed the Pylontech to hybrid inverter connection. Do the 3rd party bms's provide the capacity to have that thermal feedback control of the charge rate?Caesium wrote: ↑Thu Jan 19, 2023 3:06 pmJust seen this on another forum that I thought was worth reposting here.Joeboy wrote: ↑Tue Jan 17, 2023 12:47 pm9 degs is as low as I have seen displayed on my bms software and that's with minus 12 outsidemarshman wrote: ↑Tue Jan 17, 2023 12:28 pm Spot on Nowty. I don't think there is any concern about temperature rise due to high rate discharge or charging. The issue is low temperature charging. I am in the soft south "desert" where temps usually only dip below zero over night when the batteries are usually charging so not an issue for me. BUT up t'north it may become an issue if the batteries are in an uninsulated outbuilding.
This is from the EVE datasheet and specifies charging rates for various temperatures:
Its actually a bit lower than I would have expected. So for a single set of cells in series (280Ah) at 10c you need to be careful that you don't exceed 56A charging at the top end of SOC, which is actually pretty close to what a lot of us are doing with 70A chargers or so.
Just worth noting I think that its not as simple as being able to stuff 1C into these if you're above freezing; it tapers off quite significantly.
19.7kW PV SE, VI, HM, EN & DW
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Deep insulation, air leak ct'd home
Zoned GCH & Hive 2
WBSx2
Low energy bulbs
Veg patches & fruit trees
Ripple 7kW WT & Gen to date 19MWh
42kWh LFPO4 storage
95kWh Heater storage
12kWh 210ltr HWT.
73kWh HI5
Deep insulation, air leak ct'd home
Zoned GCH & Hive 2
WBSx2
Low energy bulbs
Veg patches & fruit trees
Re: Yet another DIY LF280K Storage Battery
Sort of. My JK BMS has a low temperature cutoff, so you can set a temperature at which it stops charging entirely. But you can't set a sliding scale of decreasing charge rates, it doesn't have anything that fancy.
Probably the best I could do is set a low temp cutoff of 10c or something. But on the other hand, my batteries are indoors under my stairs and its generally 15c+ there, even now in the depths of winter, so I'm not too worried.
But for others here with batteries in outbuildings and attics, definitely be aware.
Re: Yet another DIY LF280K Storage Battery
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Last edited by marshman on Sun Jun 11, 2023 10:27 am, edited 1 time in total.
Re: Yet another DIY LF280K Storage Battery
So jealous of your stack size
I'm tempted to get a third set mostly for redundancy; I could have any one pack out of action for maintenance/balancing/checking connections etc and still have plenty of capacity to see me by, but I think it can wait for now. No space for it anyway!
Re: Yet another DIY LF280K Storage Battery
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Last edited by marshman on Sun Jun 11, 2023 10:26 am, edited 2 times in total.
Re: Yet another DIY LF280K Storage Battery
Absolutely epic storage, you'll be well sorted for winter days there!
Are you on eco7 or Intelligent Octopus for winter charging?
Are you on eco7 or Intelligent Octopus for winter charging?
10x 405W JA Solar panels (4.05kWp) @ 5 degrees
3x 405W Longi panels (1.22kWp) @ 90 degrees
16.5kWh DIY LifePo4 battery
Solis inverter/charger
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64kWh Kia E-Niro
3x 405W Longi panels (1.22kWp) @ 90 degrees
16.5kWh DIY LifePo4 battery
Solis inverter/charger
0.6kW Ripple WT
64kWh Kia E-Niro
Re: Yet another DIY LF280K Storage Battery
Really nice build! The luxury of some serious storage!
12x 340W JA Solar panels (4.08kWp)
3x 380W JA Solar panels (1.14kWp)
5x 2.4kWh Pylontech batteries (12kWh)
LuxPower inverter/charger
(Artist formally known as ******, well it should be obvious enough to those for whom such things are important.)
3x 380W JA Solar panels (1.14kWp)
5x 2.4kWh Pylontech batteries (12kWh)
LuxPower inverter/charger
(Artist formally known as ******, well it should be obvious enough to those for whom such things are important.)