JeepHammer
Solar Wizard
- Joined
- Nov 15, 2019
- Messages
- 1,149
Me too.
That final connection, that first hook up, I still pucker up...
Cross yourself, say a chant, swing a chicken over your head (annoys the chicken) and flip the switch...
High Voltage DIY LiFePO4
- Thread starter fafrd
- Start date
Me too.
That final connection, that first hook up, I still pucker up...
Cross yourself, say a chant, swing a chicken over your head (annoys the chicken) and flip the switch...
SilverbackMP
Solar Addict
- Joined
- Apr 4, 2022
- Messages
- 1,008
On the welding bit, I was under a deadline (plane ticket to Seoul) and realized I had hooked up one of the BMSs backwards (despite checking a million times). Quickest way to fix it was just to pull them all at the BMS unit located out side of the box. I did pretty good at keeping them separated. But it’s not a horseshoe or hand grenade lol. Burnt a crimped on pin off.
Interesting thread - went a similar route here:
48s 304Ah EVE with a Batrium BMS. Emulates Pylontech HV, tested with Growatt SPH and Sungrow SH10RT - works with both while the Voltage is too low for the Sungrow, runs at only 15A.
Next step: BMS "Proxy" to attach a second Growatt
48s 304Ah EVE with a Batrium BMS. Emulates Pylontech HV, tested with Growatt SPH and Sungrow SH10RT - works with both while the Voltage is too low for the Sungrow, runs at only 15A.
Next step: BMS "Proxy" to attach a second Growatt
OffGridForGood
Catch, make or grow everything you can.
48S
so you operate between 120-160v 15A But this in only about 2kW - yes?
so you operate between 120-160v 15A But this in only about 2kW - yes?
I've been looking for info along these lines and stumbled my way into some nice batteries and charger/inverters. Similar, but specific, so I started a new thread here:
https://diysolarforum.com/threads/energen-hv-battery-and-bel-inverter-system.66180/
https://diysolarforum.com/threads/energen-hv-battery-and-bel-inverter-system.66180/
copec
Solar Enthusiast
- Joined
- Jan 23, 2021
- Messages
- 337
Solar Guppy
Red Cobra Guppy
To much of a potential hazard for home energy storage the old Li-ion, stick with LiFep04.
With the Growatt it is 25A, operational voltage more in the 144-170V range so in general a solid 4KW w/o any converters.
Set up in 4x12s, fused on both ends. Coupled into a single string via a PV switch, fused again and connected to inverter via dc relay.
Running that since beginning of the year and charged/discharged more the 2.5MWh since.
Next step is replacing an other inverter with a second of these hybrids.
Still considering whether to build a canbus proxy, run a second BMS in parallel or just use like a lead battery with that and potentially a 3rd one within a reduced voltage range.
Needs fuses and interlinks upgraded and additional relays per inverter controlled by the bms but should not be an issue.
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OffGridForGood
Catch, make or grow everything you can.
Interesting.
What do you see for no-load idle consumption?
I am curious if increasing DC voltages reduce Idle consumption, or no impact.
What do you see for no-load idle consumption?
I am curious if increasing DC voltages reduce Idle consumption, or no impact.
Never measured as there is never a no load situation - EPS output is continuously active and powering half the house. Would not expect a significant difference though due to very low/ no load but standby is always (as long as not cold) inefficient
Edit: charged, balancing while still charging at 0.6A for cell #1. local time 1:20 PM
Power and SOC 72h in addition.
Summary: works as intended and with necessary precautions HV DIY is possible. Fully acceptance tested as legally required in Germany btw
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Last edited:
Anyone know if this HV BMS balancers all cells in a 100S pack or only cells within an 10-28S "acquisition unit"Same here: https://m.aliexpress.us/item/3256804396944825.html?spm=a2g0n.detail.1000014.6.39e4Kc3MKc3MM1&gps-id=platformRecommendH5&scm=1007.40000.326746.0&scm_id=1007.40000.326746.0&scm-url=1007.40000.326746.0&pvid=0ea844ad-1608-4612-968a-68fbd79b8dc9&_t=gps-id
122S for $985
or 120S for $904
or 103S for $870
or 100S for $835
I am looking at a DIY 120S using LiFePo 50 Ah cells . Max Charge Voltage 420V and Min. Pack voltage 315V - should give 19.5 kWh. Configuration would be 5 packs of 24S with the 5 packs connected in series to get the 120S 420V. This will be used with a Goodwe Hybrid Inverter with no BMS comms
I would suspect both (but don’t have any actual experience with these products).
MyK3y
Hack
My mate deconstructed a Nissan Leaf battery pack to build a 48V system. It was a lot of work and a PITA - creating the BMS loom alone took a couple of days. Making bus bars, building a rack to hold the cells - all in all, counter-intuitive to me.
I don't like the idea of transforming 24V DC to 240V AC as you end up losing about 8% in the process. Transforming 405V to 240V ends up in losses of about 2%.
I'm going to use a 405V Nissan Leaf 24kWh pack as-is. No deconstruction of the pack, use it and it's control systems in place
I've got an RS485 <> CAN-BUS controller that allows the Inverter to talk to the pack by converting the battery CAN data into Modbus RTU registers
Hook it up to a Fronius Gen24, tell the controller what kind of battery to emulate (Tesla, Leaf, etc.) and you have a 24kWh pack with integral BMS at no extra cost or effort than the CAN <> RS485 controller (US$25)
Other advantages are - weatherproof, safe, reliable. Being an EV pack, you can orient it in any plane - I will mount it vertically against the wall below the inverter. It has all sorts of nice bolt holes that are handy for mounts.
One thing my mate found - after a year and a half of use, the overall state of charge of the pack retuned from 56% to over 80%. Probably due to the much more gentle solar charge/discharge cycle, compared to hauling a tonne and a half around.
Packs here in NZ run to NZ$3000-4000
I don't like the idea of transforming 24V DC to 240V AC as you end up losing about 8% in the process. Transforming 405V to 240V ends up in losses of about 2%.
I'm going to use a 405V Nissan Leaf 24kWh pack as-is. No deconstruction of the pack, use it and it's control systems in place
I've got an RS485 <> CAN-BUS controller that allows the Inverter to talk to the pack by converting the battery CAN data into Modbus RTU registers
Hook it up to a Fronius Gen24, tell the controller what kind of battery to emulate (Tesla, Leaf, etc.) and you have a 24kWh pack with integral BMS at no extra cost or effort than the CAN <> RS485 controller (US$25)
Other advantages are - weatherproof, safe, reliable. Being an EV pack, you can orient it in any plane - I will mount it vertically against the wall below the inverter. It has all sorts of nice bolt holes that are handy for mounts.
One thing my mate found - after a year and a half of use, the overall state of charge of the pack retuned from 56% to over 80%. Probably due to the much more gentle solar charge/discharge cycle, compared to hauling a tonne and a half around.
Packs here in NZ run to NZ$3000-4000
Nice project! Could you share details on the controller you use?
MyK3y
Hack
LilyGo ESP32 CAN<>RS485 - all details at: https://github.com/dalathegreat/BYD-Battery-Emulator-For-Gen24
CAN<>RS485 controller: https://www.aliexpress.com/item/1005003624034092.html
European Guy
New Member
- Joined
- Nov 24, 2021
- Messages
- 15
Great! we will have a Nissan Battery "left over"by next year or so. It's an 44 kW, 2018 battery. Just tested it and the SOH was close to 100%. We use the car ourselves, load only via the nanny plug (230V, 16A), never drive it empty etc. I considdering to use it off grid as we do have a 12 kW Deye hybrid inverter. I like this idea of leaving it all together.
Hey OffGridForGood. Liking your posts. I've not read to the end of this thread all the way yet, but I've been in search of, "Are there any single phase 240V (60hz) high voltage inverters on the market at this point in time?", for a few months now. Well, for me 100v 60hz as I'm in Japan.
So far a few of us over on Dala's discord have discovered the Solis s6 11.4 and this past week that FoxESS may also have a model (US 11.4kw) that take HV storage batteries up to around 400v or so.
With his battery emulator there are many now bringing online their salvaged EV car packs.
My endeavor is to use the 24kWh pack out of my Nissan Leaf. Still researching though.
Hope that helps. I'll keep reading as there's a lot of great info on this forum!
This^^^This bring me to the main subject of this thread (High Voltage DIY LiFePO4). Why DIY when car manufacturers put billion in development of high voltage battery who including high quality cells, BMS, contactors and all the engineering and security stuff inside battery who finish at scrap yard everyday?
To me it clear, simply use those high quality batteries and stop throwing money to have low quality chinese cells and BMS.
If NMC of NCA chemistry fear you, I have good news for you because Tesla, Ford, GM and other start to use LFP cells in their cars
I'm with you on that point yabert. We think exactly alike it seems on this. I think more and more will be realizing this here shortly.
Liking your posts yabert. Thanks for sharing.
Hey MyK3y. You beat me to the punch. Nice!
Glad to see others singing our tune. Are you on Dala's discord channel?
I picked up a 30kWh Leaf pack for $600 delivered here in Japan a month or two ago and swapped it into my newly aquired 2014 Nissan leaf.
Was a super easy conversion as I didn't have to dissemble the packs at all. Just disconnect, unbolt and reverse the process. Dala's can-bus converter works flawlessly. Great group over there!
So now I have this 24kWh pack just sitting while I research the best inverter to get. Looking at the Solis or FoxESS currently as I think only these two are available in single phase which is what I'm told I need here in Japan as our electrical system here was based on the US system after the war, but set at 100v 60hz instead of 120v.
Trying to find out if Solis and FoxESS are good brands or not and if they'll work at 100v in Japan.
Regardless, I'm happy to see more people realizing the benefits of HV storage connections for new inverter models. With all the used EV packs about to hit the market it's a cheap way to get an ESS system set up if you have the DIY interest.