LiFePO4?

BoFuller

My current system;
12 Kyocera 235 GX panels
16 Trojan L16RE-B batteries
Outback VFX3648 3600 Watt 48 volt inverter
Outback Flexmate MPPT 80A charge controller
Outback Mate3 
780Ah system
Generac 11k backup generator 

Its been 6 years and the batteries are wearing out - several bad cells

I’m thinking of switching to LiFePO4 batteries. MeritSun says two 7.68kwh units would do it. Would two 10kwh be safer?
Also, what is the danger with cold temps? We are currently getting down into the 20’s at night. Do I need a heater in the solar shed?
Could the batteries be in the house?

Dave Angelini

Not many batteries of any type are listed for living or conditioned space! This is for safety and insurance reasons.

LFP needs to be kept from freezing and especially charging below 32F/  You need to keep them warm during cold weather.

Never heard of the make and would just add that an expensive battery is best when supported by a name brand North American company for support if warranty is needed. Most log temperature for warranty also. Just once could ruin cells and cause them to leak. They are fairly safe from fire.

Keep your old battery cables if you do this or buy 2 batts to have a spare if one fails. Tough decision to be having to think of heating a battery but it is doable.

Photowhit

Without speaking to the problem with keeping the lithium batteries warm...

BoFuller said:

Would two 10kwh be safer?

It will always be safer to have higher capacity with lithium, since low SOC won't destroy lithium batteries.

BoFuller said:

My current system;
12 Kyocera 235 GX panels
16 Trojan L16RE-B batteries

Your current system seems a bit light on array, though you are in a very sunny area!

You have 2x370ah=740 amps at 48 volts, and can only charge at 2820 watts array x .8 NOCT value = 2256 watts / 48 volts = 47 amps so well under 10%. 

Have you extended the absorb time as your batteries aged?
Been equalizing them regularly? Will the underperforming cells not come back with corrective equalizing?

This is the 2nd time I've heard of RE batteries under performing. Really only heard good things about them until recently.

Photowhit

Specs for equalizing these is 64.8 volts!!!

L16REB_TrojanRE_Data_Sheets.pdf (trojanbattery.com)

BoFuller

Have you extended the absorb time as your batteries aged?
Been equalizing them regularly? Will the underperforming cells not come back with corrective equalizing?

I have never adjusted absorb time. I just let the system do what it’s programmed to do. Sorry, not real knowledgeable about that.  I also did not equalize very often - maybe annually?  I did equalize a couple days in a row when I first discovered the low cells, and it did not make any difference.

jtdiesel65

My solar shed is heated (and cooled).  I don't want my inverters, etc running when it's -20 or even 20. Things break at temperature extremes.

Will Prouse just recently had a new name brand LiFePO4 battery start leaking. Some of these name brand batteries seem to be made from cheap DIY cells. Not sure if the cause is known, but it happens. I don't think they should be in the house.

MrM1

@BoFuller Hey,  if you're not a DIY type of battery person, You might want to reach out to someone like Battle Born Batteries.  They are now producing some products that have self heating for the cells.  I'm sure if you reached out to them, they could let you know if they have a solution for your needs

https://battlebornbatteries.com/product-category/lifepo4-batteries/

BoFuller

Thanks, I’ll pursue some type of heating for the solar shed, or at least the battery box.

JBoyKey

These have built in heat strip and are well built and reasonably priced. https://www.signaturesolar.us/products/h7590c9c2a/2203789000006324403 
David's review - https://www.youtube.com/watch?v=SYJ25izYSGc&t=6s 

mcgivor

Nice informative video for a reasonably priced battery suitable for those who don't want to DIY, OK ney sayers, have a field day.

Solar Guppy

Just another option if you choose not to have a UL listed storage solution, and are OK with the idea that in effect the warranty period is only as long a signature solar is in business.

Getting a name brand like BYD battery box does cost more, but you can actually install with permits and company that is the business of selling storage solutions globally. 

Dave Angelini

Hey Guppy !  Also nice to have a valid home insurance policy. One does not want to have a weasel clause to cancel a policy even if the battery had nothing to do with the loss. A wind storm blew trees into houses. A few Insurance companies did not pay up here recently because of power systems that were not approved or inspected.

Also, there are plenty of name brand batteries in the store here at wind/sun ! These are good folks who pay the bills for this. I personally support them all I can.

mcgivor

The Signature system is UL listed for the cells, one would have to read between the lines of the small print to come to a conclusion wether it meets the requirements of the restrictive imperitaves often outlined  permit applications.

For those who have less constraints or are installing outside the domicile  it is a viable option, as far as who will be in business as far as the warranty extends is not something I'm willing to put my c**k on a block for, one law suit can ruin any company, big or small.

Having no wager in the outcome, either way, it is of little interest to me one way or another, but in my opinion is, warranties are designed to sell products, not to protect the end user, they are written by lawyers for lawyers and they will weasel their way out of replacing a defective product the best they can.

Dave Angelini

Listing for insurance purposes is for the whole battery system. The cells being listed mean nothing in an insurance claim!
 Nothing!  If that is not important then experiment all you want! Just do it with eyes wide open and be informed!



If you buy a battery from the store here, they do stand by their sale and will assist if you have an issue with a manufactures warranty.
I know of a few! Anyone who says the warranty does not matter probably does not live in North America. I do the same also for my clients and use the store here for them sometimes!  Hard to beat Wind and Sun!

Photowhit

BoFuller said:

Have you extended the absorb time as your batteries aged?
Been equalizing them regularly? Will the underperforming cells not come back with corrective equalizing?

Sorry, not real knowledgeable about that.  I also did not equalize very often - maybe annually?  I did equalize a couple days in a row when I first discovered the low cells, and it did not make any difference.

Doesn't sound like you have the time or interest to maintain your battery bank, A maintenance free solution sounds right!

If you would like to recover some of the capacity you should try corrective equalizing. It's more than pushing a button to do maintenance equalizing. You continue equalizing until you see no improvement in your cells for a couple hours.

Trojan recently moved it's equalizing voltage to 2.7 volts per cell, that's nearly 65 volts for a 48 volt(24 cell) battery bank!



https://youtu.be/jCl5klSF4tE

JBoyKey

Ups dropped one of my 2 Gyll 48v 100ah batteries and it would not power up, James troubleshot over the phone and sent another one out which arrived in 2 days with a rma for free shipping back, on top of that They sold me the defective Battery for 800 - opened up and repaired loose wire - bing Battery for 1/2 price, was a gamble but paid off, the company rocks, my opinion. Pretty scary the way insurance work, no way to get my system to pass and no permits here in my rural county outside of Austin, Tx. Thanks for the heads up on that, just powering my Garage to save about $35 a month and the single most fun/exciting/awesome project EVER.

SignatureSolar

Hi Guys, the cells in G4LL (now EG4LL) are UN38.3 rated as well as UL 1973

Solar Guppy

In the video I didn't see the class nine battery label on the box?, also on the signature site no mention these should be shipped  as hazardous material ( fully regulated ) as is is more the 300 wh?

While LiFePo4 is the most docile of lithium, it still falls under the DOT regulations from my limited understand.

BoFuller

I was trying to get a couple units from China, but they only ship to San Juan and then I have to figure out customs and additional shipping. So then I was really liking Battle Born as my next option, but this setup from Signature Solar sounds very tempting.

BoFuller

 BoFuller said:

My current system;
12 Kyocera 235 GX panels

Your current system seems a bit light on array, though you are in a very sunny area!

You have 2x370ah=740 amps at 48 volts, and can only charge at 2820 watts array x .8 NOCT value = 2256 watts / 48 volts = 47 amps so well under 10%. 

Can I easily add another 3 panels? Will my current setup handle that? Or would it take a bigger inverter?

BoFuller

My county requires my lead acid batteries to be in a box that vents to the outside. A safety issue, I get it.
My question is, how about LiFePo4 batteries? If I put them in a rack, do they still need to be in a vented box? Or is just being in the solar shed (which has vents) okay?

Dave Angelini

I would ask them. It can vary depending on the year of code the county requires you to meet.

BoFuller

Dave Angelini said:

I would ask them. It can vary depending on the year of code the county requires you to meet.

I will never contact the county again, since getting my occupancy permit in 2015. I am just wanting to know if LiFePo4 batteries should have ventilation like lead acid batteries should.

jtdiesel65

They don't gas as a matter of normal use like lead acid. IIUC they can pressure release under some circumstances, but those aren't normal events. If they become punctured, they give off some stuff you don't want to breathe. AFAICT, they don't need to be vented, but I wouldn't put them in the house.

BB.

You might want to research what can happen with Li Ion batteries if they catch fire (many Li Ion chemistries can catch fire if over charged/over discharged/punctured). LiFePO4 batteries (in general) are the safest of Li Ion family. They can vent, but are very difficult to actually make flame...

However, if the LiFePO4 (and the rest) of the Li Ion batteries are actually in a fire (electrical, debris, house fire, etc.), their combustion products can include hydrofluoric Acid.

https://emergency.cdc.gov/agent/hydrofluoricacid/basics/facts.asp

While LiFePO4 batteries can make the fire scene a toxic waste site:

https://forum.solar-electric.com/discussion/comment/400249#Comment_400249

FAIRFIELD, Calif. (KCRA) —

Fifteen first responders were treated for exposure to toxic fumes after helping battle a house fire over the weekend in Fairfield, officials said Tuesday.

The Fairfield Fire Department said 11 firefighters and four officers reported feeling sick after being exposed to the fumes.

Crews responded to a fire at a home on Ash Court around 5 p.m. Saturday. There, crews found 200 pounds of lithium-ion batteries in the garage, the Fairfield Police Department said. According to officials, the batteries emitted fluoride gas after being exposed to the fire.

That's when the 15 people were exposed to the toxic fumes.

The fire department also said the incident was so toxic that crews had to throw away all the hoses and boots that were exposed while battling the blaze.

Investigators are now trying to determine what kind of business the homeowner was running.

https://gooddaysacramento.cbslocal.com/2019/06/09/gas-inhalation-fluoride-fairfield/

FAIRFIELD (CBS13) – Six first responders are recovering after a house fire in Fairfield turned into a hazardous materials incident.

The incident happened on Saturday around 5 p.m. when firefighters responded to a house fire in the 1700 block of Ashtree Court. When firefighters arrived, they found the garage fully involved in flames. While fighting the fire, firefighters found 200 pounds of lithium batteries in the garage. Due to heat from the fire and exposure to water, the batteries started giving off fluoride gas, according to a Fairfield Fire Department statement.

If the worst happens, it is not really possible to clean up HF Acid contamination (and other than using water to keep things "cool", there is not anything that can really "stop" a Lithium battery assembly on fire)--Have to take down everything to clean earth that was exposed to HF Acid (as I understand).

If I had the choice--I would personally install any LiFePO4 battery banks in a separate structure from my home. Just installing battery bank/backup genset/etc. in a separate building that is not the house is not the worst idea either.

Fires can occur with just about any electrical/fuel/battery/larger appliance technology... Following code and proper construction/maintenance is always the correct place to start. Not just a Li Ion concern...

I am not an expert here--And there are many Li Ion installations that work safely... Just be careful.

-Bill

BoFuller

They won’t be in the house. The solar shed is a separate structure.

BoFuller

JBoyKey said:

These have built in heat strip and are well built and reasonably priced. 

FYI, I just ordered some and they do NOT have a heat strip.

JBoyKey

Bummer, will not need here with batteries in the Garage, did you find out from Signature Solar that they don't have the heat strip? Can you order one? Thanks Joe,

BoFuller

JBoyKey said:

Bummer, will not need here with batteries in the Garage, did you find out from Signature Solar that they don't have the heat strip? Can you order one? Thanks Joe,

I called them and they said they were trying to keep the cost down, and that most people could find their own heating strip if needed.