Building battery from MAKITA Konion PACK

[ambroseliao]

The problem will be the thin springs that make contact with the positive terminals. They're not nearly thick or strong enough to support the max current most ebikes will need. You will also have to deal with the shocks that come with a bike mounted pack. You'll need to strap the Sony/Konions in pretty firmly to prevent them from coming loose.

I'm sure they're fine for static, low drain applications.

[amberwolf]

IIRC, Leamcorp did some testing with springs in his solderless cylindrical battery case threads.
http://endless-sphere.com/forums/viewto ... =14&t=8660
viewtopic.php?f=14&t=17912
I dont' remember them working very well.

[Doctorbass]

Spring tend tobe too thin fo rthe current demand...

I used already some copper braid... wich is a little soft and conduct alot more!

What i suggest to prople who dont want to solder or spotweld is to use soft copper braid and a little foam under it to keep pressure on the copper braid.

These braid can be used like a buss bar to parallel and serie them.

For testing cells before the assembly i made some neodium magnet test lead for testing the capacity at 1C of each cells. this is a really quick connect way and still conduct more than i expected.

you can solder on the chrome layer on the magnet.. but dont heat them too much to keep their magnetism.

Doc

[marty]

Magnets. Good idea!
Find this picture here:
Handy RadioShack Test Lead Set
http://digital-diy.com/products-and-har ... d-set.html

mag_probes_for_batteries600w.jpg (36.09 KiB) Viewed 530 times

This guy makes his own with 1/4" security system magnets. I got a bunch of them. They are chrome plated and about 3/4" long. Very strong magnets.
Find this picture here:
Magnetic Personality Test Leads
http://www.hometoys.com/htinews/aug07/a ... /leads.htm

fig3.jpg (11.3 KiB) Viewed 530 times

[Teh Stork]

I'm building a rather large pack, capable of around 1500 whr. (18s16p) It will be placed inside the bicycle frame. Using glue I'll make a permanent huge pack witch sits nicely once it's in.

I wrote some code to my arduino which does:

1. Saturate Mosfet. Cell starts discharging through a 1 ohm resistor.
2. Once the (sagged) cell hits 4V. Start timer.
3. Once the cell hits 3.7V. Print timer.
4. Shut off mosfet. Small delay. Print voltage sag. Usually in the 0.1V range.

Trouble is: these data correlate better between capacity and IR than what Doc's data does. I do not have a spreadsheet, but judging from a initial IR test - I can tell if this is going to get a good time or not.

Soo, should I change my methods to measure capacity at 0.5C and from full charge? Or should I simplify things very much and group cells judging from IR?

I plan on running my pack between 3.65 and 4.15V max, for longer trips - I'll add a 1000whr booster pack.

Opinions would be appreciated

[999zip999]

Why don't you run the pack at 3.4v-4.1v or so.

[Teh Stork]

Why don't you run the pack at 3.4v-4.1v or so.

Well, I could allways do that. Just that there is little capacity below 3.6V. The pack is so big that I'll rarely really drain it. When I'm going for my 60km round trip - I'll have around 2500whr of battery capacity And with the option to charge half-way

I look forward to getting everything fitted up and checking the actual capacity I get out from the pack while running. I've got a asphalt hybrid racer of some sort, so no huge tires sagging me down

[Teh Stork]

I'm planning on using glue to make a permament pack with my cells. A close friend of mine, in the plumber industry - suggested I should use Tec7. It is a form of silicone for everything in the bathrooms - but w/o silicone. (It doesn't stain the backside of mirrors amongst others (no vinegar)). The glue won't hold the full load during riding - but i want it to be structurally elastic and strong (no cracking).

Have anyone tried something similar?

I'm also in the finishing stages of a battery tester based on a AVR It can handle 8 cells at the same time. Or 8 konions in my case. My current setup uses irfp2907's (huge hexfets), a breadboard and a shit ton of small wires. Clearly not ideal, but a nice proof of concept. Going to etch my first pcb soon, maybe it's going open source if it doesn't screw up somehow

[marty]

Here Doctorbass uses tape.


Here Doctorbass uses the plastic seperators from the Makita packs.


Here is a web photo gallery of Doctorbass battery building projects. This is from 2009. Sure that he has perfected his methods by now.
http://voltev.com/doctorbass/

Glue would be a horrible mess if you ever needed to disassemble a large battery pack.

[granolaboy]

I'd still like to know where people are finding dozens and dozens of these power tool packs. I've phoned around all the recycling places, and the local dewalt representative, and nobody has any, or is willing to part with them (well, aside from buying them new or used in working condition of course, which is ridiculous)

[marty]

I tried dealing with this place.
http://www.recycle.net/
Click on Battery Recycling / Other Battery Recycling / Lithium Content Battery Scrap OR Lithium Ion Battery Scrap / View Listings
Forget exactly how that place is set up but I paid $50 for [Pay Per Lead Service: 50 Credits]
Looked at Credits Spent at recycle.net Think I used all my credits?
Long story short. Unless you have $$$$$$ for 50,000 pounds or so of used batteries and more money to transport them, Just forget it.

[Doctorbass]

I'd still like to know where people are finding dozens and dozens of these power tool packs.

My uncle is working for these places

I have a good familly

Doc

[Teh Stork]

I'd still like to know where people are finding dozens and dozens of these power tool packs. I've phoned around all the recycling places, and the local dewalt representative, and nobody has any, or is willing to part with them (well, aside from buying them new or used in working condition of course, which is ridiculous)

I contacted makita customer service norway (my country), and after some 10 emails - I could pick 100 used packs up from the local makita workshop. I gave them a quick intro in what i was doing, + that packs often had 2 out of 10 cells broken. Adding that I'm a student definitely didn't hurt either. I'm sure dewalt, bosch and others could offer me even more cells, but my 680 working cells will hold for my pack, my booster pack, and a wiffy ebike in time

[mistercrash]

I plan on building a 14s14p battery pack with these Konion cells. Do I need a special charger to charge this pack once it's done? Can I charge it with the charger I use now for my 48V SLA? Or can I charge with a RC charger like the CellPro 10S I have?

Thanks.
Ray

[Doctorbass]

I plan on building a 14s14p battery pack with these Konion cells. Do I need a special charger to charge this pack once it's done? Can I charge it with the charger I use now for my 48V SLA? Or can I charge with a RC charger like the CellPro 10S I have?

Thanks.
Ray

Never use SLA charger for charging lithium!.. they are not stable and don’t have constant current and constant voltage generally.

A for 14s, a Meanwell power supply is better ( if you attach one of these current limiter board it’s better)

I know that some europeen are selling 14s RC charger.. and also one of the hyperion is 14s capable too, ask Ggoodrum

Doc

[IBScootn]

What "current limiting board" are ou referring to?

[Doctorbass]

What "current limiting board" are ou referring to?

I see 19 post you have.. so i guess like many other new members here you are not so famillar with the.. SEARCH tool of the forum hey hey.. no worrie

This forum have Half million post ! (491433) so....

....Just make a search with: current limiter baord

and you will find the second thread talking about that!:

Fechter's Mini Meanwell Limiter Board

[Teh Stork]

Here Doctorbass uses tape.
Here Doctorbass uses the plastic seperators from the Makita packs.

Glue would be a horrible mess if you ever needed to disassemble a large battery pack.

Shorted your quote some.

Well, these are nice setups - but if you factor in electrical wiring + volumetric efficiency, glue would be superior. From doc's experiences, test and build your pack capacity and IR matched; and you shouldn't need to ever take it apart again.

I'll be sure to document it once I get going

[mistercrash]

I plan on building a 14s14p battery pack with these Konion cells. Do I need a special charger to charge this pack once it's done? Can I charge it with the charger I use now for my 48V SLA? Or can I charge with a RC charger like the CellPro 10S I have?

Thanks.
Ray

Never use SLA charger for charging lithium!.. they are not stable and don’t have constant current and constant voltage generally.

A for 14s, a Meanwell power supply is better ( if you attach one of these current limiter board it’s better)

I know that some europeen are selling 14s RC charger.. and also one of the hyperion is 14s capable too, ask Ggoodrum

Doc

I was pretty sure that using a SLA charger was not a good option but I had to ask anyway. Thanks Doc B, the Hyperion looks like a cool option for me since I can also use it to charge my lipos for the RC heli and trucks.

[mistercrash]

Doc I answered your PM from today but my internet got a little funky so either it went out and you get it several times or it didn't go at all. Anyway the answer is yes 30 packs please.

Thanks

[Doctorbass]

Doc I answered your PM from today but my internet got a little funky so either it went out and you get it several times or it didn't go at all. Anyway the answer is yes 30 packs please.

Thanks

Answered 30 reserved for you

Doc

[mistercrash]

Woohoo! This has been an expensive morning, the Konions, a Hyperion EOS 1420i charger, two server power supplies and a couple Hyperion 7s balance connectors. But it will still end up being half the price of the other alternatives I was looking at. If I'm lucky enough to get 224 good cells then I'm going 14s16p.

[mistercrash]

Is the Doctor in the house?
I have a question but I will start with a quote from the OP.

"- make sure to charge the cells to the same level BEFORE TO PARALLEL THEM TOGETHER.. or ensure to have less than +/-150mV difference

-Before to use the pack flully charge ALL the cells to 4.1V or 4.2V.. (4.1 will prolong the life of these cells but will give you a bit less capacity)"

Does that mean I have to charge all the cells individually to 4.1V before paralleling them? I was hoping to be able to parallel them first and charge a bunch of cells at the same time. Charging individually would take such a long time.

Thanks Doctorbass

[999zip999]

That's about right ( 230 ) some 12v packs wil have 5p at 2.39v. And they mite ship a 19v at 3.8v and one bad or all good.I charged all cells to 4.0 then in there factory string. They will show if you watch. Lot of checking.

[ambroseliao]

Does that mean I have to charge all the cells individually to 4.1V before paralleling them?

Short answer, Yes! Charge individually, measure and mark the cell voltage on the cell, find all that are with ~150mV of each other and make your pack.