18650 battery pack build Kepler style

[ridethelightning]

Are you using any protection on the pos. end to keep that solder wick from shorting on the neg. Case ? Like a gasket ?

What would you use as gasket material, or is there a ready made source?

i used suade leather as gasket on my lg pack. abrasion resistant,heat resistant,soft/plyable, easy to cut to shape, hot glues well.

the cells own protection gasket melts through in a split second to the touch of a soldering iron or hot metal, as i found out when soldering on the pos end=LIGHTNING!
card could be another good material.

the other thing about having a gasket is i think it protects the cells from excess heat if soldering bus bars across the spotwelded tabs

 

[ridethelightning]

It's a work of art Kepler and instantly impressive. I want to build my own 13S 1000W battery (therefore it won't be so beautiful), to fit my bike, but have trouble finding a compact BMS. Could you give me a clue on the brand and source of your controller ?

Mike

id say an adaptto mini-e would be an awesome choice of controller/bms/charging system for a bike like this 8)

 

[Allex]

Actually a Micro-e, Mini-e is too huge!

 

[Kepler]

Are you using any protection on the pos. end to keep that solder wick from shorting on the neg. Case ? Like a gasket ?

What would you use as gasket material, or is there a ready made source?

i used suade leather as gasket on my lg pack. abrasion resistant,heat resistant,soft/plyable, easy to cut to shape, hot glues well.

the cells own protection gasket melts through in a split second to the touch of a soldering iron or hot metal, as i found out when soldering on the pos end=LIGHTNING!
card could be another good material.

the other thing about having a gasket is i think it protects the cells from excess heat if soldering bus bars across the spotwelded tabs

The gasket material is certainly the way to go. I am sure I saw these for sale on one of the battery sites. Just cant find it at the moment.

In regards to how easy the cells own protection melts the fact that my soldering method didnt melt any of the protection is a good sign that heat was kept to a minimum while soldering.

 

[Kepler]

It's a work of art Kepler and instantly impressive. I want to build my own 13S 1000W battery (therefore it won't be so beautiful), to fit my bike, but have trouble finding a compact BMS. Could you give me a clue on the brand and source of your controller ?

Mike

I got the BMS from Paul at EM3ev. He seems to have taken BMS systems down from his web site though. Might be worth shooting him an email.

 

[Kepler]

Thanks for the detail on this one Kepler. That's some nice clean work.

The solder wick trick is cool. Your idea?

No, not my idea. I think plenty of people have used solder wick for this purpose before. I havent seen the use of compressed air to quickly cool the cell after soldering used before though.

I would not recommend using solder wick for high current packs though. In the case of 18650 packs were you only have a max of 5A per cell, I think the solder wick is a good fit for the job. Worth noting that I use 2 solder wick bridges per series connection. This means a max of 10A through each of these bridges. I would not go any higher than this and would add a third series bridge if it was 5P 6P setup.

 

[Kepler]

Gave the pack its first serious run yesterday. Used 7.5Ahrs from the pack pulling a fairly consistent 500W. Pack got down to around 50V. Bench checked the voltage of each cell group. Was spot on 3.62V across the board. Very pleased with that. 8)

 

[tomjasz]

It's a work of art Kepler and instantly impressive. I want to build my own 13S 1000W battery (therefore it won't be so beautiful), to fit my bike, but have trouble finding a compact BMS. Could you give me a clue on the brand and source of your controller ?

Mike

I got the BMS from Paul at EM3ev. He seems to have taken BMS systems down from his web site though. Might be worth shooting him an email.

There was a bit about not expecting a warranty and then, poof, gone...

 

[999zip999]

Cells are fine, but with a 80watt iron and a plastic melting protection ? Bad combo.

 

[Kepler]

More detail please. Personal experience soldering 18650 cells in this manner? Perhaps direction to a thread where soldering was unsuccessful and caused the cells to fail prematurely.

I must admit, if I was doing it again, gaskets on the positive side of the cell definitely would have been used. That's Ok though and hopefully others will learn from my oversight.

Soldering with the method I used I am quite comfortable with. Note sure if I would have tried it with a brand new batch of Panasonic cells but the $200 I outlayed for these reclaimed cells, I am happy to take a chance and manage the risk.

 

[ridethelightning]

i think it is not too late to slip a piece of thin gasket material, even paper, under your goot tape, where it crosses the edge of the cells on the pos side.

i dont think the heat would have been a problem with your method myself. just worry about the goot chafing through somewhere and poof!

 

[tomjasz]

I'm going to use and have ordered the Goot. Now I need gaskets. I have also ordered shrink wrap to repair salvaged batteries. I think I found a great source to recycle from.

Gaskets adhesive.
http://www.ebay.com/itm/80pcs-cardboard-1x-18650-battery-Insulators-Electrical-Insulating-Adhesive-Paper-/321384842597?pt=US_Rechargeable_Batteries&hash=item4ad4078565

 

[agniusm]

Beautiful pack build.

 

[tomjasz]

Answered my own question with better search terms!

http://www.batterysupports.com/80pcs-cardboard-1x-18650-battery-insulators-electrical-adhesive-p-347.html

Cheaper shipping by eBay.
http://www.ebay.com/itm/80pcs-cardboard-1x-18650-battery-Insulators-Electrical-Insulating-Adhesive-Paper-/321384842597?pt=US_Rechargeable_Batteries&hash=item4ad4078565

 

[Kepler]

Perfect. Good find.

 

[Kepler]

i think it is not too late to slip a piece of thin gasket material, even paper, under your goot tape, where it crosses the edge of the cells on the pos side.

i dont think the heat would have been a problem with your method myself. just worry about the goot chafing through somewhere and poof!

I did exactly that yesterday. slipped a lightweight cardboard spacer under each positive link. Worked perfectly. Much happier now as I was a bit disappointed in myself not installing gaskets in the first place. kind of took the gloss off a good project.

 

[tomjasz]

Perfect. Good find.

A good find for a pefect idea. The flux coated Goot is genius. Thank you! Thanks to agniusm for the lead!

 

[Kepler]

Beautiful pack build.

Thank You agniusm. I have watched your pack builds over the past couple of years and always been very impressed with your work also.

 

[tomjasz]

Beautiful pack build.

Thank You agniusm. I have watched your pack builds over the past couple of years and always been very impressed with your work also.

Excellent threads, and good clear information from both. Thanks!

 

[tomjasz]

Any updates on the pack performance? I've assembled about 2/3rds of the tools and parts. The good is interesting stuff. It adheres very quickly when soldering trial batteries. I've been practicing my speed on through away batteries. The good is cheap enough as a learning material too.

 

[tumich]

Kepler, You made perfect case for 18650 cells. You are my idol You should design cases for request! I'm sure You will have alot of orders. I could be first for my next bike. I see you have a decent processing equipment and big talent. Many people using modern bikes but sellers still don't offer modern big capacity battery packs for bikes. Only Bosch but max 40 cells and cost many $.
You inspired me to make similar on frame but in 3D printer from abs and for 91 cells. I'm not sure that it will enought durable. I will check.
You can be sure thats these cells not had more than 1-3 months. I don't cheat people. I had only 1 series which has 4-5 months. Also now I have for sell Samsung and Panasonic's moreover better discharge than LG.
Hope You will use cells from me for long time.
Greedings

 

[tomjasz]

I've made up my mind to follow suit and build my first pack. Number one will be with recovered cells just because I'm so green and they're cheap. I'd like to do my second pack with the cells in this thread, but have much to learn. One of my buds who has been of enormous help in my adventure made some comments and I'm hoping for some feedback.

Here is the text of those comments,

"The problem with those cells is that the are all low-C rated Cells."

Much better would be the Power Tool "High-Amperage" cells like the Samsung 22P or 25R Cells or the Sony VTC5 cells.

You trade a little capacity for the higher output cells, but they will last longer.

For low current controllers (Less than 20A) those cells may be OK, but you will want a fairly large capacity pack (15 Ah) to supply the current. They are best at 1 "C" or at most 1.5 "C" discharge."

Comments? I'm not asking Tumich to defend his cells I'm just trying to have a better understanding. Realize I'm build ingfor a 24V 10AH SLA replacement first, and then 36V 10-15AH next. I'm going to use salvage cells for the first learning experience.

 

[tumich]

I've made up my mind to follow suit and build my first pack. Number one will be with recovered cells just because I'm so green and they're cheap. I'd like to do my second pack with the cells in this thread, but have much to learn. One of my buds who has been of enormous help in my adventure made some comments and I'm hoping for some feedback.

Here is the text of those comments,

"The problem with those cells is that the are all low-C rated Cells."

Much better would be the Power Tool "High-Amperage" cells like the Samsung 22P or 25R Cells or the Sony VTC5 cells.

You trade a little capacity for the higher output cells, but they will last longer.

For low current controllers (Less than 20A) those cells may be OK, but you will want a fairly large capacity pack (15 Ah) to supply the current. They are best at 1 "C" or at most 1.5 "C" discharge."

Comments? I'm not asking Tumich to defend his cells I'm just trying to have a better understanding. Realize I'm build ingfor a 24V 10AH SLA replacement first, and then 36V 10-15AH next. I'm going to use salvage cells for the first learning experience.

I'm not defend my cells. LG are recommended for low discharge <5A for get hight capacity as people shows on graph on my topic. For higher dc better are Samsung or Panasonic -(about 95% capacity under 10A dc). It strange that Bosch using Samsung or LG random on his Powerpacks. But Bosch motors 250W in config cells 10S4P have low dc.
Sorry for offtop.

 

[thekubiaks]

Just gorgeous work Kepler.

 

[tomjasz]

I'm not defend my cells. LG are recommended for low discharge <5A for get hight capacity as people shows on graph on my topic. For higher dc better are Samsung or Panasonic -(about 95% capacity under 10A dc). It strange that Bosch using Samsung or LG random on his Powerpacks. But Bosch motors 250W in config cells 10S4P have low dc.
Sorry for offtop.

Thanks I wanted to make certain you understood I was not critical of your cells. It is obvious, given the users, you provide a good product. Since I am looking to replace 10s5p you answered my question. Thanks. It suddenly sank in. I'm using them, rather will use them on a 350W motor and 18A controller.