Rebuilding an Li-Ion Tool Battery with Li-Po Pouch Cells (Ryobi P189)

[RukyCon]

So awhile ago, i picked up a used Ryobi drill from a thrift store, so I could give it to my father (so that he could have something that was slightly better than his Drill Master drill with a broken battery mount), but with that drill came a dead P189 1.5 Ah battery, since my charger refused to charge it, i decided to take it apart, I found that all 5 of the 18650 cells in the battery were discharged to less than 0.5v, so knowing that the cells in it were pretty dead, i ended up setting it aside, unsure of whether i would repair it.

Anyway, about a week ago, i dug up the battery again, and this time wondered if i could rebuild it using Li-Po pouch batteries instead of 18650 batteries, the main reason being that i don't have any tools for spot welding nickle ships onto the cells, and i hear that soldering the cells may damage them, so after doing a bit of measuring and looking around online, i found these batteries that seem like they should work without needing to do major modifications to the battery housing (i am a bit skeptical of their rated capacity, but as long as their over 2000mAh, i would be happy).

Now i do have my concerns with the project, mainly revolving around possibly drawing too much current from these cells and causing them to puff up or worse, so i thought i'd ask here and see what any of you have to think about this project, and so i could be told if its a bad idea before i try pulling it off, tahnks.

[stj]

i doubt it will work.
you need to remove the protection boards from the lipo's because they arent going to handle more than an amp or so,
but i also doubt the cells can provide high bursts of current.

[RukyCon]

I know the protection boards on the cells would have to go, maybe I could just get one or two cells and test how much current I can draw from them and whether it would be enough for some power tools. Of course, this could all be wishful thinking on my part.

[sam_sam_sam]

I would highly recommend that you do not use pouch batteries for this as a replacement for tool battery packs

I would recommend that you look Battery hookup for some tool rated 18650 li-ion batteries

Unfortunately right now they do not have any in small quantity available right now but just keep checking because from time to time they have some for sale I just checked

AliExpress—>

You can get 18650 with the tabbing already on the battery but you would also need the tabbing material to join them together do not go with using regular wire because it might not fit in the enclosure you can get these batteries from AliExpress but be careful to not get non brand batteries recommend brand ( Panasonic Samsung LG [ Sanyo only certain series type ] but make sure that they are ( tool rated batteries drain current of at least 10 amps continuously ) you will have to look at the data sheet for this specifications of the battery )

AliExpress <—

I would caution you that if and when you re-cell this battery pack make sure that you have full battery voltage when using the battery charger made for the battery pack when the battery fuel gauge shows that they are fully charged and that you can fully load the battery pack and it can deliver full current to the tool because one of the failure is that they can no longer can deliver full current or if can it can only for a short period of time and not for long or the other failure is that it will not fully charge up or not at all

One note if you can not get any voltage from the battery pack after putting it on the battery charger and you have put power to the positive and negative battery terminals and put it back on the battery charger and still does not have voltage on the battery terminals then the BMS protection board is in failure mode and would probably be unrepairable if you have full battery voltage but it can not deliver full current the mosfet failure and sometimes it can be repaired but not always

I hope this helps you if decide to re-cell this battery pack I have done this in the past with this brand and this battery pack in question and it can be done I will probably go back to re-cell-ing my battery packs again because the battery packs have gone up in price again

Here are some more failure with these battery packs are the following

All fuel gauge led lights flashing when battery pack is depleted not sure exactly what this failure is and how to fix it

One fuel gauge led light flashing and not wanting to charge not sure exactly what type of failure this is either

Or while you are using the battery pack all of sudden all of the fuel gauge led flashing but turning off the tool and restarting the tool seems to correctly the issue but sometimes happens not sure exactly what this type of failure is either

Here are some signs of battery cell or battery cells failure

Very short running time
Not wanting to charge battery pack ( could be batteries unbalanced battery voltage between battery cells ) recharge individual battery cell to 4.2 volts then discharge battery pack ) and recharge battery pack on charger and retest individual battery cells and see if they are still unbalanced between battery cells if so battery are at there end of life sin drum and need to be replaced

[RukyCon]

Okay, but does soldering onto 18650 cells damage them, as I remember hearing that some time ago, which was one of my main reasons for looking at these pouch cells, since I wouldn't need to buy a whole extra (presumably expensive) tool for connecting them together, I do have a fair number of (working/tested) salvaged 18650 batteries, but pretty much all of them have been salvaged from laptop packs, which means they aren't suitable for this application.

When it comes to batteries from AliExpress, isn't there the possibility that someone can take a generic no-name cell and put some heat shrink on it to make it look like a better brand? And then sell it as such.

[stj]

they can re-sleeve them, they are more likely to be salvaged though.
try looking here:
https://budgetlightforum.com/forum/b...s/rechargeable

[sam_sam_sam]

Originally Posted by RukyCon

When it comes to batteries from AliExpress, isn't there the possibility that someone can take a generic no-name cell and put some heat shrink on it to make it look like a better brand? And then sell it as such.

Yes this can happen but you have to know what the seller reputation is and go from there ( price for each battery cell if it very cheap is good indicator that it could be fake for good quality brand name batteries they are going to be about $4.00 to $6.00 per cell on average

eBay is also another source but the same thing holds true

You can safely solder the tabs from cell to cell as long as you do not stay on any one cell for a long period of time you should be ok if you have a temperature controlled soldering iron and you set your temperature to 775* F and use good quality solder you can do this very easily

You can buy a battery operated battery spot welder for around $40.00 I used one to put together a 27 battery cells into a battery pack and I did at least 6 to 8 spot welds to each end of each battery cell

[stj]

batteries sold for vaping are good, they are 30-35A drain capable
10A will be useless - i wouldnt use that for anything but a flashlight