Used Makita pack teardown

[dequinox]

I recently acquired 1000lbs of laptop batteries, but have yet to really start the teardown and recovery of 18650 cells from those.

Before I got those, however, I got about 8 or so makita + other tool packs and started tearing those down. I'm starting this thread to cover that battery build. I am thinking if I can recover enough of these I may have enough for a smaller 29.7V pack. I'm hoping to get enough for 8s6p, and I have a total of 54 cells that show 3.1V or higher. We'll see what happens, but this is more for practice and skill building.

Box o junked batteries



One of the makitas shelled:



SF US18650V... still researching to see if I can find some testing data on these. Candlepower sometimes has thorough cell testing.



The fruits (we'll see if they're rotten or not...)



View attachment 1

 

[Punx0r]

Could be sony konion us18650vtc5

 

[999zip999]

Best to leave taps on to solder too. Or do you have a spot welder. Use a gasket on the pos. side. The whole case is neg. Careful I have had used Makita cells reverse polarity and catch fire on more than one occasion. I think because of etage or may have been dropped in water. Bought used as returns so can't know the history. I store battery projects in old barbeque. Fire control.

 

[dequinox]

I'm removing the taps, I know I'll get some crap for it from people who think they know better, but I have my reasons. I'm trying to decide between gaskets and around-the-edge heat shrink. I know I'll need to insert an insulation barrier of some kind there.

You will see why I'm separating the pairs once I start posting photos of my cell testing setup. I do have to build it first however....

 

[999zip999]

The best reason for pulling the taps is for the gasket on the positive end a must.

 

[dequinox]

I've started my initial charge of the makita pack cells. I've separated them into groups of cells that are within 100mV of eachother, and I'm parallel charging them on the Accucell8 with it on the Liio setting. I figure using the lipo setting probably isn't a good idea...

The cells, as near as I can tell with a quick google search, are around 1.5 Ah each.

View attachment 1



Please let me know if anyone has a definitive capacity (manufacturers) for these. I will be doing capacity testing, I just want to be able to watch and go "hey that single cell shouldn't be getting 9Ah of capacity..."

 

[bellfador]

I have19s US18650V from 36V/2.6A/h bosch battery brand 2009. Now capacity is 870 mA/h and 75 mOhm internal resistance for each cell...

 

[Doctorbass]

I have well documented these Green Konion US18650V in hundreds post here since 2007, make a simple search and you will find info you need for these cells coming from the Makita pack :wink:

Doc

 

[marty]

I have well documented these Green Konion US18650V in hundreds post here since 2007, make a simple search and you will find info you need for these cells coming from the Makita pack :wink:

Doc

Konion Makita LiMn battery care and feeding by Doctorbass

 

[dequinox]

Thanks Marty, and Doc! I just got the 1st set of 15 charged. They are resting at 4.02v now, and I plan to let them sit a few days to see if any drop. The voltage may be reading up to 0.2v low... shit harbor freight multimeter.

 

[Syonyk]

You're using a Harbor Freight multimeter for lithium batteries? You might want to calibrate that... a few tenths of a volt is the difference between a happy lithium cell and a badly overcharged one.

The straight up US18650V cells should be 1600mah per cell.

 

[999zip999]

When I used used konion cells in 10p for my pack I would use 13ah out of the 15ah pack without bms as they would start drifting. At 40amps. Do you have a spot welder.

 

[dequinox]

You're using a Harbor Freight multimeter for lithium batteries? You might want to calibrate that... a few tenths of a volt is the difference between a happy lithium cell and a badly overcharged one.
The straight up US18650V cells should be 1600mah per cell.

I do have a HF multimeter on these as a mere check. I'm charging them in parallel on the Accucell, and that should have a pretty close V readout. I am taking readings with the multimeter right after a charge, then after a few days to see if the voltage is dropping on any of the cells.

When I used used konion cells in 10p for my pack I would use 13ah out of the 15ah pack without bms as they would start drifting. At 40amps. Do you have a spot welder.

I'm working on that :wink:

_ _ _ _ _ _ _

I'm about halfway through charging these... I don't think this is going to be a very big pack. I think I've got at most 50 cells to work with, and I need it to work with a 24-36v cotroller on a hill-topper kit. This is intended for a project I just started... I'll post a project thread soon (a few weeks probably).

 

[Syonyk]

You know you can get brand new LiMn cells, 2250mah, for under $6/cell, right?

http://www.batteryspace.com/hi-discharge-rate-sony-lithium-18650-rechargeable-cell-3-7v-2200mah-8-14wh---us18650v3-0-66---un-38-3-passed.aspx

 

[999zip999]

What ? I don't think he will be buying more cells anytime soon. Would you with 1,000 lbs of cells.

 

[dequinox]

Several people have told me I can just spend money on new cells... yes I can use google, no I don't need to be told there are "better" options. I am an adult who made an adult decision to acquire this lot of recycled batteries based on information I've researched myself. I've seen enough success (through DrkAngel on here, Rinoa Super Genius on youtube, and in other places) that I decided to give it a go. I'm not doing it to be efficient with my time and get to a functioning battery as quick as possible. I'm doing it to learn more about building packs, about how the cells behave, and how to manage them once they are in a pack. Yeah I could just read about it... but then I won't really learn by doing, which is kind of how I have to do things.

The biggest reason I am dicking around with used cells is if I make a mistake after buying brand-new cells, then I'm out several hundred dollars.

If I f*ck up working with the laptop packs, then I'm only tossing a few dollars into the shredder. These (the tool cells in particular) are an order of magnitude cheaper for me to learn on... especially since they were friggin' free.

 

[999zip999]

I thought you did it because your wife loves battery packs. Just the thought of having so many batteries makes me excited. More battery porn. My heart is beating faster. Taking my HK catalog and going to my room.

 

[markz]

You know you can get brand new LiMn cells, 2250mah, for under $6/cell, right?

http://www.batteryspace.com/hi-discharge-rate-sony-lithium-18650-rechargeable-cell-3-7v-2200mah-8-14wh---us18650v3-0-66---un-38-3-passed.aspx

You know that batteryspace.com is grossly over-priced, right?

 

[Syonyk]

You know that batteryspace.com is grossly over-priced, right?

Ok. Where would you order from that is selling legit cells? I'm going through a lot of US18650V3s lately rebuilding BionX packs.

 

[999zip999]

Where do you live ?

 

[markz]

http://ru.nkon.nl/sony-us18650v3.html
Cheap, around 2 euros so $2.25usd and the shipping to N.A. is at a good price.

Also
https://endless-sphere.com/forums/viewtopic.php?f=14&t=54094

These Sony US18650V3 are only 10A cont. but they are so cheap. ~$3 canadian, so I wish I had a US deposit account.

How much did you spend on the used Makita pack and how much did you get?
How many 18650's are there in each pack?

 

[Syonyk]

Where do you live ?

USA. And I would greatly prefer new, legit, unused cells, which is annoyingly hard to find in the 18650 world.

Though that site looks reasonable. How are they shipping to the US? I thought you couldn't ship bulk lithium cells except on freighters.

 

[dequinox]

Where do you live ?

USA. And I would greatly prefer new, legit, unused cells, which is annoyingly hard to find in the 18650 world. Though that site looks reasonable. How are they shipping to the US? I thought you couldn't ship bulk lithium cells except on freighters.

What makes you say it's difficult to find new cells? Just a quick search and I turned up some samsungs between $4 and $5 each:

http://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias=electronics&field-keywords=samsung+18650
http://www.ebay.com/sch/i.html?_fro...amsung+18650.TRS0&_nkw=samsung+18650&_sacat=0

If you're concerned about getting screwed on Ebay or Amazon, you can always develop a few useful rules by which to shop. Mine are don't buy from any seller with less than 98% satisfactory rating and like qty 1000 total sales (the second isn't hardfast, it's more about asking the question "is this seller established?"), and don't buy from any seller that's not based in your home country. Paypal protects you from fraud in most cases w/ regards to ebay purchases, and amazon has similar protections to my understanding.

Here's a pretty good bulk buy: http://www.ebay.com/itm/20-PCs-SAMS...-HIGH-DRAIN-/311364572065?hash=item487ec653a1

The user has a 99.8% feedback with 1180 ratings. I can tell by looking at his comment stats that he's been doing most of his business in the last year, and you don't get to a 99.8% positive rating by frocking people over for a year. I'm just saying, consider the basic sources for 18650's before you go off to some obscure website looking for a miracle $2.50 per cell deal... no offence markz! By the time you pay shipping on those the cost is going to go up significantly...$3.13 per cell if you buy 50 of them. That isn't so bad, but just be aware you're buying from another country (The Netherlands)... so if something goes wrong and you're not satisfied, you may have a language/culture barrier to contend with. I'm not saying it's a bad idea; I'm just saying be aware!

 

[Syonyk]

Samsung cells are not useful for rebuilding BionX packs, which use the US18650V LiMn cell.

I don't like switching chemistries or even manufacturers on a pack unless I know something about the BMS, which I don't for most of the packs I rebuild.

 

[markz]

Shipping is cheap on them actually, only if you buy bulk, like 79+, so it works out to 60-33 cents added per cell.

1-78qty is 27 euro/$40cdn/$30usd
79-154qty is 45 euro/$67cdn/$50usd
155-309qty is 90 euro/$134cdn/$101usd

that was for some 18650's I cant remember what they were precisely shipped to western canada eh!

You save like 40%, so $3.33 per cell SHIPPED, instead of $5/cell from ebay + whatever their shipping cost is.