Has anyone built a pack from these Samsung prismatics from Battery Hookup?

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https://batteryhookup.com/products/samsung-12s-43-2v-8-5ah-367-2wh-lithium-ion

They're so cheap I can't help but look at them, and I'd try to assemble a 48-52v pack. But how are they attached? Seems like they're spot welded together.
 
I dont know about that pack, but it looks like there are flat taps on the cells with laser welded busbars.
One option could be to cut the busbars in the middle between two cells.
Then use edges that is left to make connections, but in the picture it looks like there wont be very much material left to work with.
I think it is probably best if you can use them in the configuration they are if possible.
 
j bjork said:
I dont know about that pack, but it looks like there are flat taps on the cells with laser welded busbars.
One option could be to cut the busbars in the middle between two cells.
Then use edges that is left to make connections, but in the picture it looks like there wont be very much material left to work with.
I think it is probably best if you can use them in the configuration they are if possible.
Probably; they'd be going on total garage-built trashbikes, nothing good, my only concern would be that the cutoff works properly from the BMS on an odd series.
 
I bought three of those but have only broken into one of them to try it out. The cells are welded for sure, to aluminum bus bars:

IMG_20220802_114548938~2.jpg

I left the relay (which requires 12V) and the fuse, but bypassed them for the purposes of my testing. The package could be made significantly flatter by removing those components and their mounting bosses.

I ran the pack on my bike that's set up for a 44V battery, and it did what it purported to do.

There's a lot of medium-annoying disassembly required to get all the way to the cell module. Worth it if you're going mega cheap, but it's a factor to consider.
 

Did you capacity test? At what rate? What was the result? Advertised capacity?

Thanks for the reply.
 
CONSIDERABLE SHOUTING said:
Chalo said:
I bought three of those but have only broken into one of them to try it out. The cells are welded for sure, to aluminum bus bars:

And how are you charging it? 12S seems odd.

I use a Meanwell HLG-240H-54A, restricted to 48.6V. That's 4.05/cell or about 85% SOC.

12S is pretty great for 48V systems, because the cutoff threshold for most controllers is 3.33V/cell. If you turn down the cutoff to 38V (as I do), that's 3.17V/cell. In either case it's a healthier place to stop than what you get with 13S.
 
DogDipstick said:
Did you capacity test? At what rate? What was the result? Advertised capacity?

No I didn't capacity test. I only charge to 85% SOC. I never drop below 44V (3.66V/cell) if I can help it. I did my usual commute, typically 5 to 5.5Ah, with the battery, and it stayed within this range. The pack is rated 8.5Ah, so that's confirmation to me that it's close enough to its rating.
 
I charge to 40.50v on a different battery, which seems to have lots of life left even when its drained fully to 3.20v/cell but charged back to storage voltage levels when I get home, left overnight, then charged for an hour before I leave. Not much wh is wasted. I tested my other good battery, 50-70wh is only left on the table, not used.

Probably best to do the same with that Samsung Prismatic from Battery Hookup. I looked at it, its an odd shape for my spacial requirements, to live next to another battery inside the triangle.
 
Chalo said:
I use a Meanwell HLG-240H-54A, restricted to 48.6V. That's 4.05/cell or about 85% SOC.

12S is pretty great for 48V systems, because the cutoff threshold for most controllers is 3.33V/cell. If you turn down the cutoff to 38V (as I do), that's 3.17V/cell. In either case it's a healthier place to stop than what you get with 13S.
Hm, pretty high-level stuff for a newbie like myself. Thanks for detailing.

I'm very interested in keeping it within these safe limits physically and not simply just trusting a BMS or other electronics to do so for me, but how do you balance the cells later on? I've got one little BG-8S BatteryGO devices and it seems like I could nab a Kit like this to make balance leads? Or do you do something else? Or is it folly to balance half the pack, then the other and I should find an alternative?

EDIT: for the Record, I'd likely buy one of their 12S BMSs that are like, $25 to properly protect the battery.
 
CONSIDERABLE SHOUTING said:
I'm very interested in keeping it within these safe limits physically and not simply just trusting a BMS or other electronics to do so for me, but how do you balance the cells later on?

I use active balance boards on my 12S packs. They're not battery management; they only step in and balance cells whenever imbalances appear. Voltage, charging and discharge limiting must be handled by other parts of the system.

https://www.ebay.com/itm/402983558630
 
Chalo said:
CONSIDERABLE SHOUTING said:
I'm very interested in keeping it within these safe limits physically and not simply just trusting a BMS or other electronics to do so for me, but how do you balance the cells later on?

I use active balance boards on my 12S packs. They're not battery management; they only step in and balance cells whenever imbalances appear. Voltage, charging and discharge limiting must be handled by other parts of the system.

https://www.ebay.com/itm/402983558630
Huh, seems to just *always* balance instead of BMSes typically doing top balancing. Do you ever charge it to full then? Or only ever to that ~85% maximum?
 
CONSIDERABLE SHOUTING said:
Chalo said:
CONSIDERABLE SHOUTING said:
I'm very interested in keeping it within these safe limits physically and not simply just trusting a BMS or other electronics to do so for me, but how do you balance the cells later on?

I use active balance boards on my 12S packs. They're not battery management; they only step in and balance cells whenever imbalances appear. Voltage, charging and discharge limiting must be handled by other parts of the system.

https://www.ebay.com/itm/402983558630
Huh, seems to just *always* balance instead of BMSes typically doing top balancing. Do you ever charge it to full then? Or only ever to that ~85% maximum?

I've charged it higher a couple of times to add some reserve range, but generally speaking I only ever charge to 85%. (I should specify that I'm talking about other 12S packs and not the 8.5Ah module from Battery Hookup. I've only road tested that module a single time.)

The 12S pack I've had in operation for the longest is a 20Ah module from a Mercedes Benz mild hybrid. It's slightly more energy dense and compact than the Samsung 8.5Ah module, but less power dense.
 
Chalo said:
I've charged it higher a couple of times to add some reserve range, but generally speaking I only ever charge to 85%. (I should specify that I'm talking about other 12S packs and not the 8.5Ah module from Battery Hookup. I've only road tested that module a single time.)

The 12S pack I've had in operation for the longest is a 20Ah module from a Mercedes Benz mild hybrid. It's slightly more energy dense and compact than the Samsung 8.5Ah module, but less power dense.
Okay; looks like Amazon has basic switched-mode power supplies for ~$20 that I could charge one off of. I'd MUCH rather do something similar to your meanwell but it seems to high-level unless your response is that it has trimming pots inside- and I also hate spending more money on something that's supposed to be cheap and fun :mrgreen:
Did you use the already-present wires for your balancer Chalo? Or did you have to solder them?
 
They’re cheap because their capacity is very low for the volume. They’re around 4-5x the size they need to be for a bike. My last ebike battery was 2.5x the size with 12x the capacity
 
CONSIDERABLE SHOUTING said:
I'd MUCH rather do something similar to your meanwell but it seems to high-level unless your response is that it has trimming pots inside- and I also hate spending more money on something that's supposed to be cheap and fun :mrgreen:
Did you use the already-present wires for your balancer Chalo? Or did you have to solder them?

The Meanwell power supply has two accessible trim pots-- one for max voltage and one for max amps. You don't have to commune with it through arcane incantations.

I soldered all the sense leads in my regular-duty battery by scratching and tinning the bus bars first. The 8.5Ah one being discussed has a pattern of screws that are coupled to the bus and could be used to attach sense wires. That's my intention anyway.
 
Chalo said:
The Meanwell power supply has two accessible trim pots-- one for max voltage and one for max amps. You don't have to commune with it through arcane incantations.

Too late, praying anyway.

I soldered all the sense leads in my regular-duty battery by scratching and tinning the bus bars first. The 8.5Ah one being discussed has a pattern of screws that are coupled to the bus and could be used to attach sense wires. That's my intention anyway.
Sounds easy enough. Thanks!
 
Chalo said:
I bought three of those but have only broken into one of them to try it out. The cells are welded for sure, to aluminum bus bars:

IMG_20220802_114548938~2.jpg

I left the relay (which requires 12V) and the fuse, but bypassed them for the purposes of my testing. The package could be made significantly flatter by removing those components and their mounting bosses.

I ran the pack on my bike that's set up for a 44V battery, and it did what it purported to do.

There's a lot of medium-annoying disassembly required to get all the way to the cell module. Worth it if you're going mega cheap, but it's a factor to consider.

Hi Chalo,

Would you be willing to verify the 11"x7"x3" dimensions battery hookup lists? I'm trying to decide if this is right for my application and I find their dimensions a little vague.
 
NateTN said:
Would you be willing to verify the 11"x7"x3" dimensions battery hookup lists? I'm trying to decide if this is right for my application and I find their dimensions a little vague.

I get about 12 x 7 x 4" including the tabs, standoffs and other appendages. By trimming off extraneous parts, I think it's feasible to get down to 11 x 7 x 3". That would remove the fuse and relay and the furniture that holds them to the cell module.
 
Chalo said:
I use a Meanwell HLG-240H-54A, restricted to 48.6V. That's 4.05/cell or about 85% SOC.

Interesting. How high can this Meanwell be pushed. Can it be used on a 14s pack for ~90% SOC? (57-58 volts?)
 
Diggs said:
Chalo said:
I use a Meanwell HLG-240H-54A, restricted to 48.6V. That's 4.05/cell or about 85% SOC.

Interesting. How high can this Meanwell be pushed. Can it be used on a 14s pack for ~90% SOC? (57-58 volts?)

Yes. It's rated to adjust +/- 10%, so it should be good for at least 59.4 volts.

Because it delivers constant current, it's probably not a good idea to blast 5-6 amps into a battery right up to its maximum voltage, but it shouldn't be a problem if you're only charging to 90%.
 
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