Konions self balance and self charge

[John in CR]

Some of have known for a while that Konion cells pull some magical self balancing thing. They self balance charge too. I had some leftover 4s2p blocks from my last pack build last August. The 6 blocks had not been touched or connected to anything since then, and had the overnight resting charge that I marked on them in August, about a .5V variance between the highest and lowest voltage packs. Last night I was demonstrating that lithium batts have a low self discharge to a friend and measured the voltage of these blocks expecting them to be slightly lower. To my surprise, they were all higher and even better, they were all equal (max diff .02V)!

If anyone has an explanation, I'd like to hear it. The only thing I can think of is that it is a couple of degrees C warmer than in August. After my discharge test in August, I let the 4s2p blocks get to a resting voltage overnight before recording it right on the pack itself.

 

[Doctorbass]

These cells are Magic... stop searching further! :wink:


Doc

 

[liveforphysics]

The cells in the pack all have walkie-talkies built into them, and they call each other up, chat a bit, ask what voltage level they are at, and then gift-wrap a nice little package of coulombs, and send it over to the low cells via a tiny ebike courier service.


Seriously, I don't know, but I've seen the same behavior, and it's freaking nice for folks using the Mn spinel chemistries.

 

[neptronix]

I'd like to see what the hell happens on these with a balance charger or celllog 8s attached.

I don't believe in magic.. and i hope you don't

 

[spinningmagnets]

I read somewhere that Justin at ebikes.ca sells more LiMn packs than any other type...

 

[Doctorbass]

The cells in the pack all have walkie-talkies built into them, and they call each other up, chat a bit, ask what voltage level they are at, and then gift-wrap a nice little package of coulombs, and send it over to the low cells via a tiny ebike courier service.


Seriously, I don't know, but I've seen the same behavior, and it's freaking nice for folks using the Mn spinel chemistries.

Yes.. that's what i meant by Magic!!

 

[auraslip]

Someone, we all know who , should convince hobbyking to sell limn packs.

I've seen LiMn pouches on alibaba....

Alternatively, doc should packify them so newbs like me who are afraid to solder cells can take part in the fun!

 

[aaronski]

agreed I would like to see lnmn pouch cells. I have 72v 6.6ah pack of them, and there's so much wasted space and weigh with all those cans. part of the reason I switched to the lipo.

 

[neptronix]

li-mn pouches at a good price? naahh.. that would be too good to be true

The ultimate cell would probably be a nano-tech Li-MN... no balance charger needed.. constant output well over 5C..
Ah.. one can dream

 

[John in CR]

I just want matched Sony US18650V cells in 10s2p tab welded blocks for under $.20/wh including shipping. I'll take it from there. They are made by the millions, so $.50/cell in tab welded blocks shouldn't be too far off the mark at the factory direct level.

 

[999zip999]

Hay John can I have that factory direct phone #

 

[John in CR]

Hay John can I have that factory direct phone #

800-CallSony. Sorry I messed up the math, $1/cell is all we need. I would go as high as $2/cell including shipping if they are matched tab welded blocks. Another potential source would be the factory supplying the Makita packs, because their 5s2p packs would suit me fine. There are also copycat packs to fit the Makita powertools, so that has potential too.

Many of the guys take the used cell blocks apart, but until you've built a pack using 4s2p blocks of 3.7v1.6ah cells with nice big easy to solder tabs at the ends, you just don't know what easy is. I create a 20s string of 40 cells with just 4 tab-on-tab solder connections. Add in the fact that conservative charge/discharge puts the cycle life past 1k with no need for BMS or balancing, and they have a moderate C rate and significantly greater energy density than LiFePo4. It just doesn't get much better. If they still self balance in prismatic form, and come in ready-made blocks, count me in, but I'll take them as-is until the next big step up in batteries occurs.

John

 

[veloman]

I wish I had this kind of luck with my pack. It could be because they are series then paralleled though.