EVE 25p 18650

TheGaben

1 µW
Joined
Aug 12, 2022
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Does anyone have any experience with the EVE 25p cells? Especially cells from Bulk Battery. I'm planning to build a 3kwh battery pack for my stealth bomber. Are they well matched? do they hold their capacity? I plan to limit my charges to 4v per cell and do 5c peaks
 
I don't know those cells specifically, but "well-matched" is typically something a pack-builder (usually a large company) will do by getting many more cells than are required for a single pack, and testing the cells' characteristics, and picking only those cells for a pack that are all identical characteristics. It's a lot of work unless (expensive) batch-testing equipment is available, so most individuals don't do this. Most pack-building companies probably don't, either.

Sellers of cells *could* do this too, but from what I've seen here on ES, they don't, as a rule.

Manufacturers of cells do cell testing and grading and batching, but a seller may not supply a buyer with cells all from the same batch (sometimes they might; you would have to ask them specifically about this though).


I don't know anything about "bulk battery"; hopefully someone else can chime in about them.
 
You get what you pay ($1.99). At that discount price they could be a bulk order of borderline A/B grade inventory...
https://www.bulkbattery.com/products/eve-25p-18650-2500mah-20a-battery?variant=40724038975685
 
TheGaben said:
Does anyone have any experience with the EVE 25p cells? Especially cells from Bulk Battery. I'm planning to build a 3kwh battery pack for my stealth bomber. Are they well matched? do they hold their capacity? I plan to limit my charges to 4v per cell and do 5c peaks

I dont know about 25P cells, but I know about EVE 26V. I think is a trusted brand! At our company we recovered thousands of 26V cells from trotinetes/escooters bankrupt company. All cells used preform great, as new ones! soo maybe good cells brand

We could trust EVE and soo 25P cells could be a nice option. Let's feed EVE Chinese company! They have nice development at 26V cells, soo we assume the other models would preform very well :pancake:

Anyway, 25P is a 20A cell, it means it could go maximum peak of 20A demand or maybe a full discharge at some max temperature to put out 2500mAh
Best to keep at half that value current limit. maybe 10A could be a statement for long life and safety..

stealth bomber needs high current delivery, If you go for 10P configuration, means 100A limit (on safety limits)
if ebike draws 120A peak , maybe U need to go for 12P configuration..

But if you want to save cash go for a bomb battery 6P (each cell 20A x 6 = 120A) :flame:
This is the minimum parallel cells configuration for 120A peak demand..

maybe stealth bomb could go sometimes to 200A..
Be on the safe side when using high current loads!! :warn:

The best cells at market are Sony/Murata(Japan) and Molicell (both for 30-35A) :thumb:

Make Your choice :bolt: :bolt:
 
Emark's link is the one I'm looking at ( https://www.bulkbattery.com/products/eve-25p-18650-2500mah-20a-battery?variant=40724038975685 )

The listing says "Grade A, matching voltage, resistance and capacity." As Amber said, its unlikely they'd do testing and match the cells themselves right? and since it doesn't say they're from the same batch, maybe they could be a little mismatched. Would more parallel cells average this out and make this less of an issue?

While I'm here, does this battery build make sense? I'm planning to design around 3kwh and 72v (18s) (so ~18p) in hopes of getting ~30 miles at 45mph-50mph
I don't plan to use peak power for long. this is more of a sporty commuter than a real dirtbike. I oversized my controller with a KLS7245 (350 peak phase amps) but my motor is a 5kw mystery motor which would surely burn up before the controller and battery. With 350 phase amps, worst case scenario if I floor close to top speed that's a quick 350 amp pulse which would still be less than 20 amps per cell.

Finally, I don't actually plan to use a full charge on my commute and rather want extra cells for occasional trips and shallower cycles, I'm tempted to charge limit them to 4v/cell and not 4.2. Would it make sense to make my pack 19s? fully charged with 19s at 4v/cell my pack would be 76v (instead of 75.6v)
 
I've bought cells, including Eve 25P's, from 18650store.con, and didn't know about their parallel operation at bulkbattery.com. I've only bought cells when they go on sale at 18650batterystore, usually about a dollar off which would make them comparable with bulkbattery prices. If I bought less than 40, the cells came in plastic boxes, and were shipped quickly. The one time he made a mistake, he corrected it. Threw in a freebie.

Maybe the bulkbattery prices are because he is selling older stock, I don't check the date codes. All I've ever done is check voltage and IR on every cell I use.

With the Eve 25P's, I've not used the cells he shipped me. Been sitting outside for 8 months, I've used some EVE 25P's I got elsewhere. Small ebike applications, Drawing around 2A per cell, 6A max. They're delivering 2.33 Ah when the pack hits LVC. These cells came from BatteryHookup, and were in a 13S-9P battery that failed QC. It sure did, as the nickel lifted off easily, so I was able to buy them for $1/cell, Anyway, someone was using them in a bigger commercial battery application. It had a big nickel triangle fanning off the 9P ends with 8G cable to collect the current,
 
TheGaben said:
(350 peak phase amps)
but my motor is a 5kw mystery motor
which would surely burn up before the controller and battery350 phase amps, worst case scenario if I floor close to top speed that's a quick 350 amp

Finally, I don't actually plan to use a full charge on my commute and rather want extra cells for occasional trips and shallower cycles, I'm tempted to charge limit them to 4v/cell and not 4.2. Would it make sense to make my pack 19s? fully charged with 19s at 4v/cell my pack would be 76v (instead of 75.6v)

Sir, 350A peak at a 72V system (18S max 75,6V) means 75,6V x 350A = 26KW max output :bolt: :bolt:
Soo carefull with controller fit at this application , if U have a 5KW rated motor, it is able to handle peaks of 10KW and not 26KW :flame: unless U adjust by software the current limit supply..

if U have 10KW max peak, so calculate Amps I=P/U --> 10000/75,6V equals 132Ampers peak.

Soo Use a controller limited to 132A or maybe 150A (a 5KW controller will fit a 5KW rated motor!! but motor handles twice peak of its rated value continuous ie a 5KW motor takes peaks of 10KW)

Also maybe a good ideia to go to 19S battery using 75,6V charger. Doin math max charge point 75,6V/19S= 3,98V
Take into account U're battery now 20% less capacity(top charging up to 3,98V, so if cells are 3000mAh, only will output 2400mAh), but increase a lot the longevity and safety of tha battery! good ideia to keep top charge at 4,0V :idea:

Good luck with Your project :bolt: :bolt:
 
I purchased several batches of EVE 25p within the past year (from Alibaba) and the latest ones were quite bad - the self discharge is high, the impedance and the capacity spread is large, also I got some information from a friend of mine who builds batteries that these don't last long. Seems to be hit and miss.
 
I purchased several batches of EVE 25p within the past year (from Alibaba) and the latest ones were quite bad - the self discharge is high, the impedance and the capacity spread is large, also I got some information from a friend of mine who builds batteries that these don't last long. Seems to be hit and miss.
Sir, don't buy any cells from Alibaba or Alixpress, unless u know the seller as a "good friend"..
one time I bought LG HG2 from aliexpress. I received packet, great looking cells but tested at half capacity and twice impedance..
most online china trade cells are used and category B, C , D up to Z.. and reselled as new ones (great advertise.. but if cell costs low, for sure is not new or genuine! at a real world you get what you pay for! no miracle for "low cost cells")..
U are lucki to not get good looking 18650 cells with inside half size cell, filled other half with beach sand.. o_O

if You want genuine cells, just buy cells from trusted resellers at your zone If U are in Europe buy from EU trusted warehouse, if U are at USA buy at USA!
U could easy find trusted online resellers at your zone!
Or just import cells from EU to USA or vice versa. but this will need cargo ship, soo more CO & CO2 released to atmosphere to deliver orders from one continent to other!! and massive disturbs all tha sea fishes when sending by cargo ship. a cargo ship produces massive low frequencies sound dB's pressure level underwater!
📢🔊🔊

*outoftopic -- no one cares about activists (Im not one of those)!
cargo ships are a huge threat to environment! soo try to buy all internet stuff at your zone, instead of ordering from thousands miles distance!! save tha world!!
 
I've been using a 13S-3P pack made with EVE 25P's this year on my wife's ebike. Logged 16 rides, typically around 20 miles. Pack is around 48V when recharged back to 54.6V, Doesn't seem to be anything wrong with these.,.
 
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