low price Li batteries

Tear down and testing SOK battery.

https://youtu.be/RjpkI8quyzQ

Some control power with a relay. But none throttle power to limit amps. ON or OFF only.
Can't say I know too much about the options available.

time2roll,

Thanks for the information on the battery management system and mosfets. Is that in pretty much all bms units?

The OP showed a LiFePO4 so I thought it would compare. I assume the 100/50 amps is to save a few $$ for the extra MOSFET transistors in the BMS. It will take 75 days just for delivery. And you can't ship it back so forget the warranty. No store reviews or feedback is another red flag. Although it might be a great deal but I cannot recommend purchasing it.

time2roll wrote:
Here is 300 Ah for $383. Crazy low price with a few red flags of warning.

Ummm a 300 amp hour battery that only supplies 100 amps continuous?

And c/6 for maximum charging rate of 50 amps?

75 day warranty?

It does use prismatic cells, so failed cells may be replaceable.

Since I don't want LI I can be totally candid. I would not buy this '300 amp-hour' battery.

time2roll wrote:
Here is 300 Ah for $383. Crazy low price with a few red flags of warning.

And only a 2 month wait for shipping from China.

time2roll wrote:

Here is 300 Ah for $383. Crazy low price with a few red flags of warning.

https://www.aliexpress.com/item/1005002669232736.html

...with charger included. Unknown quality of both the charger and battery and no warranty. I bet the cells are pouch type. China have found a new niche to apply their unlimited supply of cheap labor. I don't even think this is a planned government-sponsored action like it was with solar panels 10 years ago.

pianotuna wrote:
Hi,

For those of you who find LI suitable to your needs--this looks like a bargain to me.

https://www.sokbattery.com/products/100ah-12v-lifepo4-deep-cycle-battery

100 Ah for $570?

Here is 300 Ah for $383. Crazy low price with a few red flags of warning.

https://www.aliexpress.com/item/1005002669232736.html

folivier wrote:
Looks interesting, great price unless shipping cost is high. I emailed the distributor in Arizona a couple questions and he expects stock in 2 weeks, warranty will be with SOK, hopefully won't have to send/receive from China.
The charge rating is 50 amps/battery so charging might be slower than Battleborns or others, but with solar or alternator charging could work out just as well.

if you watch the video of the guy doing the tests, it charged at 76 amps with no issues. 50 is the recomended charge rate but I remember reading that it would handle a 1C charge rate. charging with LFP is all about how hot the battery gets, for the most part.
If it stays cool you can crank up the charge rate, unless thee is an artifical charge limit by a BMS.

The Prismatic cells I am looking at are rated in there raw form for a 5C charge rate max, but that like I said is going to depend on internal battery heat. If you cool them you could do it but why would you want to spend that much on a charger and no plugin big enough to power it.

I do like that they are using Prismatic cells in this build and I like there box design, I wonder if they will sell bare boxes?

Steve

folivier wrote:
Looks interesting, great price unless shipping cost is high. I emailed the distributor in Arizona a couple questions and he expects stock in 2 weeks, warranty will be with SOK, hopefully won't have to send/receive from China.
The charge rating is 50 amps/battery so charging might be slower than Battleborns or others, but with solar or alternator charging could work out just as well. Only time it could be an issue is with inverter charging but you can set the max charging amp on inverter. It would just take longer for a full charge. Not a problem if plugged in but if on generator would mean longer generator run time. Depends on your usage. If the BMS limits the incoming charging amps that could protect your alternator from overworking.
7 year warranty is good especially if a USA distributor can handle any exchanges. If they have to come from China that could be a problem with time and shipping costs. I like the open case design, makes it user serviceable if needed.

The case is metal, nice for heat dissipation. I looked into them but in Canada they are less readily available and more expensive.

Charging directly off the generator's 12V outlet will be ridiculously slow (as it will with any type of battery), you will need a charger for more amps.

BMS doesn't limit the charging current, it only cuts off when battery overheats. With low internal resistance it will try to suck out maximum possible current from the alternator and could overload and burn it. Li batteries need a proper DC-DC charger between the alternator and battery, Renogy make 20A and 40A models - they are a so-so brand, maybe there are better makers out there.