I saw this on ebay http://www.ebay.com/itm/NEW-SAMSUNG-18650-36V-4-4AH-BATTERY-EBIKE-VAPE-POWERWALL-BATTERIES-20-CELLS-BMS-/201895735309?epid=1621923126&hash=item2f01ec700d:g:Mh8AAOSwSypY9Y7d 35$ seems way too good to be true. I’m assuming somebody here might be able to comment on them. Anybody bought one of these for testing? cheap enough that it doesn’t really hurt much if they are fake.
Woah…imagine a 10s4p pack for $70! Something does seem fishy here though, my guess is the cells are maybe the binned samsung ones or not genuine. Then again I am no expert so someone else here can give a better idea.
There’s a couple threads on this already. They’re using 10A continuous cells. Unless you go 6p+ you’re going to incur a large amount of voltage sag.
Still not too shabby. 10s8p would be close to 600wh for $150
could you link to them?
I’ve got them, I use them. No issues. Great stuff and at 10S6P I indeed am around 500Whr and really do get about 25 miles. It’s legit.
Can anyone who has them tell me about the physical shape? I looked at getting them for my board, but it looks like with them stacked 3 high, they won’t give me enough clearance underneath the board.
What about voltage sag since it’s only 10A ?
Definitely a few volts of SAG, but the 10Amp is continuous with a 20Amp max. Even at high speed I’m still not pulling a full 60amps through the battery and even if it’s OK to do 20Amps for a second here and there that would be 120Amps!!
Did you harvest the cells from the pre-built packs, or instead used them in their original configuration? If the latter, I’m interested to know of your experience using the included bms; does it limit the discharging capabilities in any way, or is its function merely for charging?
No Harvesting here. Just using them in their original configs. That’s a good question on the discharging from the BMS, but I don’t believe so (don’t quote me). Either way each Cell is rated for 10A cont. and 20A max making each “pack” 20A continous and 40A max. Throw two of them in there (40 batteries) and you have a nice 16mile range with 40A continous and 80A Max. That’s great for anybody. I opted for 3 packs and It’s great to have 25 mile range. I charge it every 4th ride or so (unless it’s a super long)
Awesome; just ordered a pack off eBay. Since this will be my first foray into the 18650 world (basic lipos before), can I ask how you’re charging them? Looks like I’ll have to desolder the xt60s and use a standard 42v hoverboard power supply…
I wired them all in parallel keeping the XT60 connections. Then I paralleled a connector from my charger I already have from an electric bike. It’s an XLR connector. Charging at 2Amps takes about 5 hours. No need to charge each independently.
Looks interesting. Maybe he could do some custom builds ?
Would you mind sketching/verbally describing a super basic wiring diagram of how you connected everything together to charge without needing to disconnect the xt60 connectors? This is my first time wiring everything up, and I’m a bit confused as to how to solder in my XLR charging port without connecting to the individual BMS’s. Many thanks if this is possible!
So you can see in this the XLR connector (or any connector really) will charge all the batteries at the same time. I can even remove my loop key to keep everything off as well and still charge.
Edit: I noticed the right most pack looks like it’s connected in series. It’s a mistake, but I know it’s parallel. Most might not assume the mistake so I want to make sure no one catches things on fire.
Awesome- that is so helpful. Many thanks!
Did you disassemble the packs to make them flatter? Also, are you using all 3 BMS boards, if so how do you charge it? Is there any way you can post a picture of your setup? I’m thinking about getting some of these packs for my build, but I live in SF and it needs to be able to handle some pretty serious hills.
My Buddy did disassemble the pack just a bit and he re-routed the 3 BMS boards. I kept as is. No issues, I just can’t hop curbs, but who does… I think you should re-read the posts. I put up a sketch, and I mentioned the current draw will never hit the limits, not even the continous limits in the 6P config. They are never hot either. Warm, yes, but not hot.