Dumb Lithium question - Why some very low Prices?

[mtollin]

I know all name brand Lithium manufacturers hover around $2,200 - $2,700 for 48 v 50 - 70 amp. Ignoring the fact most want 100amp, Why do I see tons of no name Lithium batteries touting these specs ranging from $700 - $1,400 on Ebay? Almost all batteries are made in China, so can't be that, so why are named brands almost double? Chemistry? Someone is using these cheap batteries so what's the bottom line here?

Here is an example:

https://www.ebay.com/itm/37366440363...Bk9SR8CDwNSLYQ

[Volt_Ampere]

Not all cells are created equal. If the price is low, the cells may be not grade A new cells. I would highly suspect anything under 1200 for a drop in pack for a golf cart.

[CP241]

Brand names aren’t all that expensive. Plowmans has an allied kit with 2 batteries (totaling 60aH) and a charger for $1757 and an 8 year warranty.


The biggest difference in the Chinese/alibaba/eBay batteries is the quality of the cells themselves in the battery, as well as the capacity of the BMS. Most of those Chinese batteries only have a 100amp BMS. Which honestly is probably usually fine for a stock cart but you may still run into some issues of tripping it up big hills and stuff.


One of the guys here has the allied 60aH setup in his cart. He stumbled across a cheap alibaba 48v 100aH lifepo4 battery locally and his brother bought it. He may see this and chime in but last I checked the cheapo battery does work quite well. He tripped the BMS immediately but once he turned his alltrax down (not sure what he limited it to). But he did mention it’s nowhere as good pot powerful as his (smaller) allied pack.

The other thing about the cheapo batteries is unknown lifespan, little or no warranty, and little to no support if you have issues.

Personally with something I’m spending that kind of $ on I like to know there’s support for it, either from the manufacturer or at least the store I purchased it from if local. If the eBay guy decides they are junk and getting a lot of email complaints all they have to do is close their account. Takes like 3 minutes to do. Especially if they are overseas, and you’ve got no options for action other than eating the loss.

[Volt_Ampere]

If you follow some of the battery builders online, you will see how risky it is to buy cells from China. What seems like a good deal often isn't - and these guys often lie about their quality and where their cells came from. Forget trying to return them if the seller isn't in the states.

[CP241]

And the battery you linked I don’t think would even hold up in a golf cart.

It’s a 48v 60aH

Their specs State max continuous discharge current is 1C (60 amps)
Peak discharge current 3-5 seconds is 2C (120 amps)

I think even a stock golf cart would likely trip the BMS on that battery

[augiedoggy]

so the more Ive researched this over the last couple years and after building some DIY lifepo4 packs the more I realized I should invest in building these things myself and selling them for large markups like some do....

The bms in that battery is limited to 60 amps continuous which is almost half of the 100amp continuous most of the other name brand solutions start out at. if you have a fancey motor and controller, this batter will be limiting it to less than stock power output. the 60ah is also a shorter run time than say trojan lead acid batteries... you would be better off looking for at least 72ah imo but it depends on your use.

Now you can buy 100ah Grade A eve cells form places like docanpower.com , have them in a week and build a 48v battery with a 500a bms capable of 240amp continous power output which is actually higher than most of the $$$ preassembled packs and build it all for well under $1200-1500 depending on how fancey with the enclosure you want to get.. prebuilt packs are nice and the support is very useful too but be cautious of sellers using older NMC or lipo style cells that have a much much shorter lifespan than lifepo4 and are more dangerous as far as fire potential. the plowmans allied battery and the eco 105ah battery are both better lifepo4 options.

Theres a lot of you tube videos on this stuff and a guy named Will (his video can be found here) https://www.youtube.com/watch?v=atYZ4RtUJhU&t=628s he tests a lot of different battery makers products and does teardown videos.

Im frugal so I ordered everything to build a 90ah 48v pack for $700 I intend on doing a build thread here when I get it done.

BEWARE of aliexpress and buying batteries shipped from china direct. the return shipping costs more to legally do than the batteries cost. That said I spent months researching sellers and hopefully the 16 90 cells I just paid 583 shipped for is as good as the 31 buyers who left feedback got... these are grade B cells meaning they did not pass testing to be used in automotive applications. many of the larger cells being sold are grade B in fact some manufacturers only sell grade b to the public or reseller as they get top dollar for thier auto grade cells they make for OEMs.

[Volt_Ampere]

I agree you can do a 100AH build for under $1500 but it's hard to find a quality drop-in for under that. Doing it as a business isn't cheap so doing it yourself should save some $$ if you know what you are doing. There is some fab work to secure the cells and connect everything. And don't forget you need a charger.
My most recent Leaf pack cost me $1500 for the cells used - but they are very high quality cells designed for EV's. I still had some fab work and I had to add a BMS. Unfortunately, getting used EV cells is getting much more difficult. You can't buy them new and many EV's now package the cells in a way that does not lend itself to using them for a 48V cart battery.

[augiedoggy]

Yes the charger run an additional $60-200 depending on amps from 3a to 30a from what ive found.
My cart charges at about 6amps off the 350w solar panel I use for a roof on it.

[Volt_Ampere]

To buy 16 EVE 120AH cells from docanpower.com will cost you $1200 plus shipping. You will probably be over $1500 by the time you get cables/connection straps, enclosure, BMS.

[augiedoggy]

Originally Posted by Volt_Ampere

I agree you can do a 100AH build for under $1500 but it's hard to find a quality drop-in for under that. Doing it as a business isn't cheap so doing it yourself should save some $$ if you know what you are doing. There is some fab work to secure the cells and connect everything. And don't forget you need a charger.
My most recent Leaf pack cost me $1500 for the cells used - but they are very high quality cells designed for EV's. I still had some fab work and I had to add a BMS. Unfortunately, getting used EV cells is getting much more difficult. You can't buy them new and many EV's now package the cells in a way that does not lend itself to using them for a 48V cart battery.

are those leaf cells lifepo4 though? I though about going this route or with volt cells but after researching it I found the lifepo4 had large advantages for me.