Lithium off-grid battery bank?

[dvellone]

Any off-grid home owners make the leap to lithium storage? My current lead acid set is showing signs of aging and the benefits of lithium sure look nice, but the cost is still several times that of lead acid, at least in my area.

I'd appreciate any input from off grid home owners who've made the leap.

Thanks, Daniel

 

[peakbagger]

You may want to stop by solarpaneltalk forum. You just named why they really havent penetrated the home market. The watt density is far less important in stationary use so the premium paid for lithium is not fully utilized.

Too bad Aquion packed it up, zinc chemistry and electrolyte that was relatively non toxic. EosEnergy has a version but their sights appear to be on grid storage.

 

[John Galt]

How long did you get out of this set?

 

[begreen]

There is a startup happening now in the Vancouver BC area that is repurposing Nissan Leaf battery packs at about 65% of the competing offerings. This will be an option to watch if they grow.

Moment Energy Home

Moment Energy provides clean, affordable, and reliable energy storage by repurposing retired electric vehicle batteries.

momentenergy.ca

 

[peakbagger]

I have chased several similar startups and they are all real good at restacking cells but where they fall down is integrating a proper BMS. Unlike FLAs, each lithium cell in the packs needs to be monitored. There are some chinese junk BMS's purported to work like this but not many legit affordable systems I have seen out there. I think Victron may make one but havent chased it down. A couple of major sellers of restacked cells for retrofit use on Fleabay usually have an asterix strongly recommending a proper BMS but rarely actually sell them. Might be okay if grandpas hot rodded lithium golf cart conversion lights up but not so nice if a home battery bank smokes.

 

[dvellone]

How long did you get out of this set?

I'd have to check to make certain, but it's been all of 8 years, likely going on 9. Though the bank (8 6-volt wired for 24v) is showing signs of aging, there's two batteries that are the big culprits. If I can find a couple batteries around the same age as my bank that are in dcent shape I can get some more time out of it.

 

[begreen]

I have chased several similar startups and they are all real good at restacking cells but where they fall down is integrating a proper BMS. Unlike FLAs, each lithium cell in the packs needs to be monitored. There are some chinese junk BMS's purported to work like this but not many legit affordable systems I have seen out there. I think Victron may make one but havent chased it down. A couple of major sellers of restacked cells for retrofit use on Fleabay usually have an asterix strongly recommending a proper BMS but rarely actually sell them. Might be okay if grandpas hot rodded lithium golf cart conversion lights up but not so nice if a home battery bank smokes.

I heard they were getting some mentoring and assistance from NIssan. Hopefully with the BMS too.

 

[jebatty]

I'd have to check to make certain, but it's been all of 8 years, likely going on 9. Though the bank (8 6-volt wired for 24v) is showing signs of aging, there's two batteries that are the big culprits. If I can find a couple batteries around the same age as my bank that are in dcent shape I can get some more time out of it.

Since it's two batteries, do you think that they could be rescued by de-sulfating or another reconditioning charge procedure?

 

[Corey]

Cost does still seem to be high on 'plug-n-play' lithium storage solutions for stationary solar power. Though there is a growing DIY group building storage packs with lightly used / repurposed lithium batteries from all sorts of sources... retired backup power supplies, decommissioned EV batteries, barely used stand-by power packs, etc. So if you have DIY DNA, the option could shave a lot of the cost.

 

[peakbagger]

Cost does still seem to be high on 'plug-n-play' lithium storage solutions for stationary solar power. Though there is a growing DIY group building storage packs with lightly used / repurposed lithium batteries from all sorts of sources... retired backup power supplies, decommissioned EV batteries, barely used stand-by power packs, etc. So if you have DIY DNA, the option could shave a lot of the cost.

I agree, darn tempting. A DIY person going in with a clear head can assemble a really slick system but a little bit of knowledge is dangerous when it comes to Lithium tech. I have a 3 MWH/500 KW industrial lithium battery on one of my projects sitting in storage waiting for the rest of the equipment to get installed and every contact with the local fire department is getting decidedly testy as the more they learn about them and the potential hazards from a failure the less they like them. At minimum its a toxic spill and short term cloud of nasty gases. The current FD approach is keep them outdoors with good setback on all sides and set up fog nozzles to keep the surroundings from burning and letting the battery sizzle and bubble for a few days until its cools down and are hopefully inert. They are being banned outright from buildings with occupancy. Any DIY person considering a lithium battery should consider it being installed in a separate location from an occupied building. That means a separate somewhat heated space to keep the batteries warm.

One of the members on Hearth, Tom in Maine rebuilds EV banks as part of his business, may be worth getting his two cents although I think he deals mostly with the older battery tech.

 

[semipro]

a little bit of knowledge is dangerous when it comes to Lithium tech.

Funny, that's where I feel I am right now with my DIY solar PV storage project.
That said, I'm fairly paranoid about burning down my house so I plan to be cautious.

 

[DBoon]

I would not put a Lithium Ion backup or power storage battery in my house under any conditions. The Lithium Ferrous Phosphate batteries have low to no ability for thermal runaway or self-combustion, from what I've read. Others may be able to offer more advice in that regard.

 

[woodgeek]

I think the repurposed automative packs will be fire safe, but a homebrew unit from a low cost outfit...I'd agree with DBoon. Maybe on a concrete slab in a garage, or an outbuilding.

 

[DBoon]

I think the repurposed automative packs will be fire safe

I would have agreed with you a week ago, Woodgeek, but my Chevy Bolt LG Chem Li-ion battery pack has now been limited to 90% of full charge while GM/LG figures out the cause of some battery fires. The technology is not terribly unsafe, but not safe enough for me to risk my home.

 

[peakbagger]

The auto battery packs are probably the worst option as they are optimized to maximize output. The trade off is if the manufacturer is in the loop they may should be able to plug into the stock BMS system.

 

[CaptSpiff]

The auto battery packs are probably the worst option as they are optimized to maximize output. The trade off is if the manufacturer is in the loop they may should be able to plug into the stock BMS system.

"may should" ??? Can you hedge that a bit more?

OK, we'll reuse this product counter to its design & intended purpose, and we'll ask the OEM for their blessing.
Lets bring in the OEM's legal team for their opinion on that.

Peak, you are my go to guy on engineering insight! Development & deployment strategy,... not so much.

(I hope I made you smile.)