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Chinese "power wall"


(stephen krywenko) #1

well I am excited just bought what looks to be a very nice "power wall’ sever rack based so you can easily add more to of them just slide them in and hook them up and go


the cell support 200 amp continuous and 500amp surge at 48volt

based on prismatic lifepo4 >2500 cycles at 100%DOD ( compared to teslapower wall NMC cylinder battery <1200 cycles to 100%DOD) not the biggest version as it only 7kw but price is not bad at 1800US ( compared in Canada a tesla power wall is +10000CAD for the same size ( then you still have the install cost after that)-- cost is not prop up by subsidies as like it is in other countries )

displays capacity and usage on the screen and I believe fully adjustable battery parameters, supports RS 485 and RS 232 so you can have full automation and display remotely and can communicate with a GTI i think it will be fun to play with… though I did also order a 7kw NMC battery pack for my electric car project for 1200US - as i wanted a higher life cycle for the “Powerwall” then the electric car project as I could then cycle it harder if i wanted then the NMC also even at 7KW the NMC on average will cycle to 40% DOD per day so on the electric utility car the life cycles should be similar to the lifepo4 in the end - )

from my estimates NMC VS LiFePo4 in power wall storage - pros/con (base on info from battery manufacture)
LFP - >2500 cycles @ 100%DOD ~7kw
NMC >800 cycles @ 100%DOD ~10kw

LFP >5000 Cycles @ 80%DOD ~6 kw
NMC > 1600 cycles @ 80% DOD ~8 kw

LFP > 10000 cycles @ 50% DOD ~3.5 KW
NMC >4000 Cycles @ 50% DOD ~5 KW

LFP > 25000 cycles @ 40% DOD ~3 kw
NMC > 9000 cycles @ 40% DOD 4KW

so comparatively so while you can buy 30% more storage capacity with NMC for the same Price as LFP battery you have <1/2 the life cycle or much less then depending on charge current and temperature… also the LFP battery is much safer for thermal run away

though if you used cylinder LFP battery compared to prismatic the cost is very similar to NMC but still maintain a higher lifecycle (1800 @100%DOD) then NMC but not as high as the prismatic LFP