Downside of LITHIUM LiFePo4 Battery?

[technerd88]

https://www.ebay.com/itm/4x-Trojan-...847560?hash=item3fb6ebd188:g:pmIAAOSwVCpcOPOo

Now these are the biggest rip off since collect calls

 

[dixonge]

also two 6v FlA are dramatically heavier and thus consumes more fuel to drive. it would take 4 of those golf cart batteries to get the same usable without damaging the batteries as lifepo4. I got 200ah for under 800 the last time, and those golf cart batteries for 669 for the same capacity and less life. nope. thats whats nope

2 6v 230aH = 128lbs - 100 pounds heavier than one LifePo4 100aH - $260 vs $949

230aH of FLA = 115aH usable
100aH of LiFePo4 = 80aH usable

Am I missing something?

 

[Spaceman Spiff]

also two 6v FlA are dramatically heavier and thus consumes more fuel to drive. it would take 4 of those golf cart batteries to get the same usable without damaging the batteries as lifepo4. I got 200ah for under 800 the last time, and those golf cart batteries for 669 for the same capacity and less life. nope. thats whats nope

Come on, now we are just getting silly.

My GC2s add 1.5% to the weight of my rig and the gas milage change is too small to measure.

How many cycles have you gotten out of your LiFePO4 batteries so far?  at what cost?
I have over 2000 cycles on my GC2s (208AH for $186) that are still working fine = $0.085/cycle.

And you are comparing new FLA to used LiFePO4 cells you have to assemble yourself.  I can get used GC2 with less than 800 cycles on them for $25 each = 200AH for $50.

 

[technerd88]

Come on, now we are just getting silly.

My GC2s add 1.5% to the weight of my rig and the gas milage change is too small to measure.

Some of them are at 3200 cycles already and still 98% capacity. Most of what I have are used and repurposed into 12v's. I bet those lead acid are on the last legs. I know battery tech, as I have been working with lead acid batteries since I was 6. I had a bike with a stereo on it and two 100ah gel cells and I wish I had lifepo4 then. There's no way your still getting even 70% capacity with those lead acid batteries after 2000 cycles even if you only went down to 60% each cycle. You can get lifepo4, not just battle born which I'd never buy, for cheaper than those golf cart batteries with only 500 cycles on em

 

[technerd88]

Come on, now we are just getting silly.

My GC2s add 1.5% to the weight of my rig and the gas milage change is too small to measure.

How many cycles have you gotten out of your LiFePO4 batteries so far?  at what cost?
I have over 2000 cycles on my GC2s (208AH for $186) that are still working fine = $0.085/cycle.

And you are comparing new FLA to used LiFePO4 cells you have to assemble yourself.  I can get used GC2 with less than 800 cycles on them for $25 each = 200AH for $50.

Do you have a victron BMV? i'd really love to see even 100ah used and that voltage drop after 2000 cycles. Lead acid works in a house where you can have racks of batteries but not in a space even as big as my trucks box. My house is a 1985 f350 14 foot box truck BTW. I know how to get the most for my money as I'm far from rich.

 

[jonyjoe303]

100aH of LiFePo4 = 80aH usable

Am I missing something?


lifepo4 you can take them down all the way to 0 percent, when the bms shutsoff. If you have 100 ah lifepo4, at slow amp use you get 100 ah, at high amp drain you might get 94 ah. Lifepo4 cells can go down to 2.5 volts, most bms will shutdown at 3.0 volts, extending cell life.

I wouldn't recommend any lifepo4 (drop-in replacement like battleborn) for any solar system. They don't work well with solar, you would have to charge at very low amp, too fast and it will activate the bms, when that happen you get voltage surges. I learn that the hard way, this applies to li-ion and lifepo4, pwm or mppt controllers.

You need a special bms (that uses contactors/relays) if you want to use any lithium with solar. Lead acid is the best choice for solar, unless you have the right bms for lithium. I started off with agm batteries and move to li-ion, then to lifepo4. I had over 200 pounds of lead acid in my astrovan at one time, I could feel all that extra weight everytime I came to a stop.

 

[Spaceman Spiff]

 . . . I bet those lead acid are on the last legs. I know battery tech, . . .There's no way your still getting even 70% capacity with those lead acid batteries after 2000 cycles even if you only went down to 60% each cycle. You can get lifepo4, not just battle born which I'd never buy, for cheaper than those golf cart batteries with only 500 cycles on em

My 2 GC2s were capacity tested to 208 AH last July (2040 cycles), 99% capacity.
They were tested by an electrical engineer that does 12V systems for a living with measurement equipment calibrated traceable to NIST.  I do monthly specific gravity tests (1.273±.003) and twice yearly equalizing charges.  I only need to add water after equalizing.

I have 200W of solar & Morningstar TS-45 PWM charge controller.  I seldom get below 70% (Trimetric reported).  I am almost always at 100% by evening.

You have not yet told us what your system cost (total, not just cells) and how many cycles you have put them through.

LiFePO4 for less than $50?

 

[technerd88]

Total system cost including the 900w of solar is about 5000. What do you run on these? Most of my cells are circa 2011. I don't ever need to go lower than 50% because I have 900ah of usable capacity. Still 98% capacity usable. You can't capacity test FLA this way, you will destroy them instantly. My newest bank performs identical to the older 26650 ones I have. I have three solar charge controllers, epever 60a each so they are not strained, 3 100w panels on each one. The older ones are a123 and full river cells. The newest prismatic ones are headway 210ah. I wouldn't keep buying them if it wasn't worth the investment to be honest . I'm a network engineer and need power to my equipment 24/7. I bet you my load on these would kill those acid batteries in less than a year. I've had most of these for 3 years so far and like I said they had life before I got them. BTW the 5000 includes my 5000w pure sine inverter and charge controllers, fuse blocks, switches, charger and 1800w inverter generator. I got a good deal did I not? it can be had.

 

[technerd88]

When I cook, making dinner for my partner and I, am at 3500w of usage when I'm making baked food like chicken in the oven and mashed potatoes and a vegetable on each side of the induction cooktop, I would kill them FLA in 6 months or less. it usually takes me an hour or two on average to finish cooking our meals but I wouldn't trade it for the world. I save so much without having to use propane too! that stuff scares me especially in a small box truck or van. I guess this is the main advantage. I'm still less than c/2 rate and it makes my system last, and saves me big bucks. lead acid is only c/10 so 235ah of lead acid is 23 amps without long term damage or c/2 for the sa,e capacity lifepo4 which is 117a.

 

[JRRNeiklot]

Just wanted to add my 2 cents here. I have two Trojan L16s for a total of 360 AH. I bought them in 2015. They are just now beginning to show a bit of age, I'm guessing they've lost a few amp-hours. I used to wake up at about 12.5 volts. Now I'm seeing 12.3. I'll probably get no more than another two years out of them. But if they die today, I will have gotten 5 years for just over $500. I would need a minimum of two 100ah lithiums to replace these. That would be around $2,000. They would have to last me 20 years to get what I've gotten out of these - and that's if mine died today. Lithium's just aren't worth it imo.

 

[technerd88]

They are worth it though. They will last forever at an even higher c rate and if you treat them like flooded , they will last 100x longer and you can do electric cooking

 

[gwave]

I got my LifePO4 for $550 shipped within the US (not claiming US made) with a 3 year warranty. Sure, it's not a name brand Battle Born or Relion, but it's a good build with a built in BMS and after a year it's been excellent. The price of them has gone up quite a bit on them and they're now priced at $699. At $550 it was a no brainer to me to buy this over 2 100ah AGMs that would take up more space and weight. And it's better than building my own.

 

[tripper]

I bought cheapie LiFePO4 drop-in batteries ( a 100 AH and a 50AH) directly from China several years ago. They have worked FLAWLESSLY for many years under extreme conditions. I have noticed no capacity loss and have used them in very cold and very hot conditions. I think I paid $650 and $350 for them. I have accidentally drained them until BMS cuts off a couple of times. The only downside I am aware of is not charging them below freezing, which really is not a problem if you keep them inside rig.  I find on freezing nights since I am pulling some current for electric blankets and such the battery stays warmer than freezing, plus my controller has a temp sensor and will not charge it if freezing. I regularly dump up to 70 amps of charging into them. Probably the best investment I have made into my RV, as previously I had used top-rated lead acids, and the AZ weather extremes seem to kill those off in a few years no matter how well maintained.

 

[Spaceman Spiff]

I bought cheapie LiFePO4 drop-in batteries  . . . I have noticed no capacity loss and have used them in very cold and very hot conditions . . .

Please define 'very cold' and 'very hot'.  Thank you.

 

[bullfrog]

Where I am it is regularly 85 degrees before 9 AM in the summer and well below 32 degrees at night and several days during the winter. I hate doing battery maintenance chores. I don’t have AC or a microwave, so I have very limited electrical needs when traveling. My Ryobi One system with the latest big batteries and a vehicle charger has ran my tools and house appliances just fine for the last 5 or so years just fine. In summer months I work and receive a full hook up space. In winter I use solar as well as a generator when necessary. All of my house batteries are kept above 80% charge most of the time. All of my house batteries and vehicle batteries are used AGMs that were discarded by house boat owners as part of failed battery banks with 12 to 14 batteries in them with only a few bad batteries. All are over 10 years old and I have only replaced one that I regularly ran down below 50% fishing at night. Over the last 15 years I have spent at most $3,000 on Ryobi tools and stuff, solar, generators and fuel as well as batteries so less than $20 a month. I spend less than 2 hours a month working to pay for power, about the same amount of time as it took to read and absorb all the information in this thread. Lol!!! So until price and tech get a user friendly product that is as good and cheap as what I have I’ll continue to stumble on blindly with HDR spending $20 a month doing what I’m doing! Sure miss Stern Wake though I’m sure mods don’t, thanks for all the interesting comments in advance!