buying Lithium batteries price question

[OverTheTopCargoTrailer]

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I'm thinking of putting together a deal for lithium batteries 12v 100 AH packs, these are equal to 200-300 ah flooded batteries, they would be able to do 2000 cycles and still maintain 80% or better storage.after that you could get another 2000 cycles but batteries then might only store 65% the batterys operate at -40F up to 145 F , however it is not recommended to charge them if if the battery is below freezing. current street price for a set with BMS is approx $850 , plus tax and shipping.

The battery's could be charged with a solar charge controller, a inverter with charger or a separate lithium charger at 15 amps approx $150

QUESTION, At what price would you guys consider purchase of lithium batteries. Their upfront cost is higher then Flooded or glass mat , but their overall cost per cycle is only 25%

Please leave your thoughts & comments.

[wtcreaux]

I'd be interested.......texas

[MtnDon]

I almost wish my CT batteries were dieing. But they are not so I can't realistically begin to think about replacing them.

But LFP is tempting for a couple of reasons; and the cold weather thing would not affect my decision as far as CT batteries goes... the cabin is another matter. How much would I be willing to spend for a 12 volt 100 AH.... ??? I'd have to give some more hard thought on that. At present you'd have to count me out. I'm trying to justify the cost of a new Alienware laptop first... LFP batteries come later. But I'll keep an eye on this thread.

[KennethW]

For a low power(led lights) user would using 2 12V lithium drill batteries be a good alternative? One could get a 12v lithium drill for the build ,then use the batteries when camping. Just a thought.

[lrrowe]

Jerry,
I would look a your opportunity, but the initial cost just may be too high for me.

I see my initial needs to be satisified by two Trojan T105's for a total of about 200 amphours of 12v's for 20 hours.
I ultimately want 4 of them. I understand that it is better not to mix old and new batteries, so while it may be overkill for me, I am prepared to get all four right at the get go.

I think i can get them for $80 each max so that nets out to $320 max.

You say a "set" of your lithium batteries are about $850 street price. Is that a "set" of two?
If yes, then the street price is close to 3x the cost for the Trojans. While over time it may be a great deal, it sure hits the pocketbook hard for one trying to add all the other extras to his CT.

[hankaye]

Howdy All;

Is this the same as the one that was posted in ottct's thread?
How much does it weigh?
How much is the shipping?
Does it need venting?
Just a few questions that come to mind regarding the feasibility.
Then there is the thing about the fires ...
so I did a quick Google and found this;
http://highvoltagehotrods.com/arent-lit ... re-hazard/
fair article (imo), as it gives some understanding without throwing anyone
under the bus.

hank

[lrrowe]

Thanks Hank.
The cost will make me think very carefully. Your post suggests that there are many facets of this technology to consider.

[MtnDon]

The LFP batteries Jerry is referencing do NOT have a fire hazard. There are many "flavors" of Lithium based batteries. They are not the same; big differences between them. The LFP, Lithium Ferrous Phosphate, batteries are safe. They do not cause fires.

They do cost more up front, but are supposed to last much longer.
They also thrive on being left in a partial state of charge, unlike FLA (flooded lead acid). Big Plus!
LFP can be killed by overcharge and too much discharge; killed quicker than FLA. Hence the need for a management system.
On the Plus side LFP can also be more deeply discharged than FLA.
LFP also charge quicker as the internal resistance is lower.
Half the weight; maybe less than half as you don't need the same total AH capacity.
Cold weather discharge capacity is greater than FLA, BUT they can not be recharged at below freezing temperatures. Not a big deal when stored in a warm place.


Lots of plus points along with the higher wallet discharge.

[lrrowe]

"......higher wallet discharge." Good one!

[Hiflyer]

Jerry,
I would look a your opportunity, but the initial cost just may be too high for me.

I see my initial needs to be satisified by two Trojan T105's for a total of about 200 amphours of 12v's for 20 hours.

Don't forget that you'll only get maybe 50% of the advertised max with batteries... So two 105 AH's, actually means 105 AH

[lrrowe]

This where my expertise, or lack thereof, shows it's ugly face.

[abqlloyd]

With lithium you might get rated discharge specs down to 75%. I've burned up RC lipos by repeated low discharge. Each lithium chemistry is different.

Decide how you are going to use your trailer and how much juice you really need. The needs of the weekend warrior are different than the full-time RV'er.

[tony.latham]

I'd love to have a lithium battery in my box, but even if the group by would be down to $500, it's too much to bite off (and I know you can't make that discount anywho). I also know in the long run, you can argue that it pencils out and win. (But who's to say the manufacture's guarantee is going to hold? I think Walmart stuck it to me on their battery guarantee, but that's Walmart.)

My current battery is a COSTCO Group 27 marine battery and it's a year old. My PVs are keeping it healthy this winter, so it should last a few more years. When it's time to replace it, I hope to be able to justify the added expense to upgrade to a Group 24 AGM. (I don't need the amp hours my 27 provides).

But thanks for toying with this group-buy concept. I hope you pull it off.

T

[OverTheTopCargoTrailer]

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Most of you are not gonna drain the battery at more then 0.5 to 0.2C so the volts stay at 13.3 until 85-95% empty
this is the best because a reg flooded battery drops to 11 volts like a rock.

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After 2000 cycles at 80% DOD...the battery still would hold 80% charge for another 2000 cycles,
then it would hold 65% charge for 2,000 more cycles. you would never touch that with a flooded $80 T105 golf cart battery.

Hi guys , I say a set of lithium because to get 12 volts , you actually need 4 cells each which is called a 3.2 volt LifeP04 cell. The battery if fully charged would peak out at 14.5 volts. If you remove about 5% it mostly sits at 13.3 volts until you remove about 80% of the voltage or charge. From there it quickly drops to 10 volts , where you need to stop as you are now 90- 95% DOD.

The lithium battery stored for a long time is best at 50% I know a guy who let them sit for 3 years no problem. You would kill your flooded after 6 months for sure.

The weight of the lithium is actually 25% of the flooded as 100 ah lithium is really equal to 200 ah flooded.

The lithium really has zero water maintenance , no gassing, no worries, allows actually 3C power draw, so you can put a 300 amp load on a 100 ah lithium battery. I have been sleeping 6 months with a 1250 ah lithium right under my bed inside the trailer. It charges perfect with my outback 80 from my solar panels. IMHO - it's much harder to kill a lithium then a flooded battery because of the battery management system - BMS , it's sort like using 2 -3 rubbers if you get my drift. - I'll add more details latter today.

Buying Lithium battery is sort of like this - if you buy 50 gallons of gas or less it's $4 a gallon, however if you can buy 400 gal storage tank and gas in one shot then it's only $1 per gallon of gas - but for the next 10 years or 4,000 gallons you get your gas for $1 a gallon as long as it goes into your big tank first !!!

It's really a absolut win, win, win as long as one time you can afford a bigger storage tank.

[Shadow Catcher]

I spent $400 for our 150AH Concord AGM. A 100AH Lithium would give more usable AH's...