Rebuilding 18V Ryobi NiCd as LiION

[Baker]

On another note, I'm thinking of repacking one of my Ryobi NiCd batteries (18V jobbie), it's totally gone - any better/more trusted/just as cheap place to purchase the cells than eBay? Not wanting to spend heaps on it.

[stumo]

Originally Posted by roscored1000

hi i actually just bought 2 of these p104 batteries from ebay and one is showing a charge but is defective when put on the charger. Did you finally rebuild the pack yourself, if so what success did you have? I am wondering if it is just a case of buying some cells and taking the old and putting the new in, is soldering involve or anything tricky? thanks in advance.

It sounds exactly like that dead one of mine. Showed a charge, but wouldn't accept a new charge.


In my case it was one of the cells that the weld had not taken, due to the rusty scrap batteries that are in these packs. You can try to solder it back on as best you can, you have nothing to loose. Just try to get some actual metal showing on the cell, and use heaps of solder and get it good and hot.

Mine seems to be holding up quite well, and is actually the grunter of the 3 I got, easily lasting exactly twice as long as my new genuine 1.4Ah packs. I haven't felt the need to do the li-po rebuild yet, but it is still on the cards as soon as one dies.

Originally Posted by Baker

On another note, I'm thinking of repacking one of my Ryobi NiCd batteries (18V jobbie), it's totally gone - any better/more trusted/just as cheap place to purchase the cells than eBay? Not wanting to spend heaps on it.

In all honesty, you are better off ditching NiCD. I got the ryobi drill kit that came with the li-ion charger and 2 of the small 1.4Ah cells (which are great for wielding the smaller hand tools) and are easily more powerful and useful that the ni-cds. It was $199 from bunnings, and you could probably easily get 50 bux for the new carry bag and drill if you on-sold them and kept just the packs and charger. I can't believe I held on to the ni-cds for so long, it really is a night and day difference. Otherwise if there is a new tool you may need, it is often a good 50 bux cheaper to just buy the tool in a kit with one li-ion pack and charger if available.

But if you wanted to be really cheap you could try to revive your ni-cd with the reverse high-current blast. It really works. But you are still left with all the things that are crap about the ni-cds. My biggest issue was that they self discharge so damn quickly, that you actually had to plan a day in advance when you wanted to use any of your one+ tools! With the Li-ions they are always G2G whenever you are, and you can leave on on a charger permanently if you really want, unlike the nicds.

[kombiman]

I changed from a hitachi 18v nicd to a Makita Li earlier this year. I give drills a flogging, use them 2-3 times a week and use them for everything from pre drilling into 50+ yr seasoned hardwood, driving tek screws to mixing mortar (see my pizza oven thread), grout (noban) and render. The Li is incredible!

[Baker]

Originally Posted by stumo

In all honesty, you are better off ditching NiCD. I got the ryobi drill kit that came with the li-ion charger and 2 of the small 1.4Ah cells (which are great for wielding the smaller hand tools) and are easily more powerful and useful that the ni-cds. It was $199 from bunnings, and you could probably easily get 50 bux for the new carry bag and drill if you on-sold them and kept just the packs and charger. I can't believe I held on to the ni-cds for so long, it really is a night and day difference. Otherwise if there is a new tool you may need, it is often a good 50 bux cheaper to just buy the tool in a kit with one li-ion pack and charger if available.

But if you wanted to be really cheap you could try to revive your ni-cd with the reverse high-current blast. It really works. But you are still left with all the things that are crap about the ni-cds. My biggest issue was that they self discharge so damn quickly, that you actually had to plan a day in advance when you wanted to use any of your one+ tools! With the Li-ions they are always G2G whenever you are, and you can leave on on a charger permanently if you really want, unlike the nicds.

I've actually already bought a replacement lithium kit, although I ended up paying a bit more and getting a nice Makita jobbie. Was just thinking of (cheaply) resurrecting the old Ryobi to let my son use.

[t3h]

Originally Posted by Baker

On another note, I'm thinking of repacking one of my Ryobi NiCd batteries (18V jobbie), it's totally gone - any better/more trusted/just as cheap place to purchase the cells than eBay? Not wanting to spend heaps on it.

Personally I'd rebuild it as LiPo instead of LiIon as there's plenty of high capacity insane power delivery cells for RC aircraft available from places like HobbyKing. LiPo is much better at high power delivery than LiIon - you can get lipo packs that can provide hundreds of amps (only for a few minutes :P). A 5S (5 series cells) lipo will provide you with 18v.

I'd actually go one further and mod the drill to have a XT60, EC3 or EC5 hanging out the bottom to plug the battery into.

http://www.hobbyking.com/hobbyking/s...%5F40C%5F.html
This is a 5 cell 3000mah pack for $35.75. 137x45x33mm, 40C constant discharge (40C * 3Ah = 120A max current), 442g weight. Charges at 5C, so with a beefy enough charger (300 watts), it can be recharged in ~15 minutes.

Just be careful not to drop it, puncture it or short it - it can and will provide a lot more than that 120A if demanded...

[Damoo]

I've got 4 DeWALT 2.4AH 18V NiCd batteries (the XRP ones), one of them doesn't hold charge for very long, I have the multi-chemistry charger also which has that tune-up charge if you leave it on over night, it slow charges all the cells, if I wanted to rebuild one, but keep NiCD batteries, is that possible rather than paying $100 or so for another two in a pack?

Or could I mod my drill to use the above packs?

Thanks much.

http://www.youtube.com/watch?v=8UQ-5QP9pks

Those batteries are the exact same ones I have

[stumo]

Ok so I've finally got round to rebuilding one of my China special Ryobi P104 packs with Li-Po cells. OMFG this thing kicks arse now.

I used 10 of these bare cells, Turnigy 2200mAh 20C (40C burst) each, in a 5S2P arrangement for a total of 4400mAh of 40C (80C burst) grunt. They totally filled the empty space left by the 10 18650 Li-ions and padding. You wouldn't be able to go any bigger without serious modifications to the internals of the pack, even then you can't go much bigger.

I have tested it back to back against my newish retail P104 2.4Ah pack from Bunnings in my garden blower, just running it continuously until the packs do the self-cutout.

• My newish retail P104 2.4Ah pack runs it for 11:42. The speed of the blower noticeably drops off after about 4 minutes use.
  
• My new LiPo 4.4Ah pack runs it for 19:53 and it canes the nuts off the blower the whole time until about 30s from the end.

By my rough calculations, those times confirm the Ah ratings on both packs. What they don't tell you is how much harder the lipo keeps the tool running, and how much cooler the lipo is at the end of the run.

Well worth doing for the $50 shipped it cost me if you have the skills.

[kombiman]

Originally Posted by stumo

Ok so I've finally got round to rebuilding one of my China special Ryobi P104 packs with Li-Po cells. OMFG this thing kicks arse now.

I used 10 of these bare cells, Turnigy 2200mAh 20C (40C burst) each, in a 5S2P arrangement for a total of 4400mAh of 40C (80C burst) grunt. They totally filled the empty space left by the 10 18650 Li-ions and padding. You wouldn't be able to go any bigger without serious modifications to the internals of the pack, even then you can't go much bigger.

I have tested it back to back against my newish retail P104 2.4Ah pack from Bunnings in my garden blower, just running it continuously until the packs do the self-cutout.

• My newish retail P104 2.4Ah pack runs it for 11:42. The speed of the blower noticeably drops off after about 4 minutes use.
  
• My new LiPo 4.4Ah pack runs it for 19:53 and it canes the nuts off the blower the whole time until about 30s from the end.

By my rough calculations, those times confirm the Ah ratings on both packs. What they don't tell you is how much harder the lipo keeps the tool running, and how much cooler the lipo is at the end of the run.

Well worth doing for the $50 shipped it cost me if you have the skills.

how do you charge it and how long does it take now compared to before?

pics?

[stumo]

Originally Posted by kombiman

how do you charge it and how long does it take now compared to before?

pics?

I just charge it in the normal one+ li-ion charger. The ryobi pack itself already has all the smarts in it for balancing and high and low cut-off and temperature monitoring etc. Sure its Li-ion specific, but its the same parameters as for li-po.

It takes longer to charge no question, haven't timed it yet.

Pics to follow, I have it all screwed together at the moment, but I'm going to tear it down and re-do some of the internal wires now that I've confirmed it pwns, so will post some pics then.

[stumo]

Pics:

This is the lipo bundle (2 columns of 5 cells each) fitted into the lower pack casing with the pack PCB hinged over to allow soldering of all the balance and main lines.
http://db.tt/D7FocRRS
Notice the big heatsink over to the left hanging off the PCB, that has the low voltage/temperature cutout FETs on it and it fits into that rounded end of the lower casing with the funny shaped circular air vents in the bottom. The other end of the casing houses the battery life gauge thingo. The lipos are a tight fit, you couldn't go any bigger really. Not shown but I put some thin rubber sheet between the cells and the PCB.

This pic is showing the stock 10x 18650 layout (with the China scrap cells) in their holding cage. I de-soldered it from the PCB.
http://db.tt/zaXPWnSf

[the3coopers]

Originally Posted by stumo

This pic is showing the stock 10x 18650 layout (with the China scrap cells) in their holding cage. I de-soldered it from the PCB.

Still shuddering at the nastiness of that Chinese repack!

Have you seen these pics of the places where those cells come from?

http://totallycoolpix.com/wp-content...ronics_020.jpg

and

http://totallycoolpix.com/wp-content...ronics_019.jpg

from pics 18 and 19 on this page (with other device recycling)...

http://totallycoolpix.com/2011/05/wh...come-obsolete/

[Sam_Q]

this is what I did:



A true 5A/H of grunt. I know this is an unusual conversion however it has some serious advantages. I can elaborate more if wanted.

I have done this to multiple power tools now, apart from the massively increased run down there is also a huge gain to the torque.

[kombiman]

Originally Posted by Sam_Q

this is what I did:

image

A true 5A/H of grunt. I know this is an unusual conversion however it has some serious advantages. I can elaborate more if wanted.

I have done this to multiple power tools now, apart from the massively increased run down there is also a huge gain to the torque.

more elaboration is wanted!

[Sam_Q]

I found my old website link:

http://s-86.com/s-batterypackupgrade.html

I can answer any questions on here. Now I know this is awkward to do but the andvantages are huge. I go for an obscene amount of time without a recharge. With any other battery chemistry the available capacity deteriates with load. So the 2A/h might be a whole lot less in actual use.

When I did my Ryobi drill I think I may have had more than quad-rupple the torque. Enough that I almost burnt my hand when I tried to stop the chuck in the high gear. I thought I would break the gearbox but it's still going.

[MyDixiesNormous]

Originally Posted by stumo

Pics:

This is the lipo bundle (2 columns of 5 cells each) fitted into the lower pack casing with the pack PCB hinged over to allow soldering of all the balance and main lines.
http://db.tt/D7FocRRS
Notice the big heatsink over to the left hanging off the PCB, that has the low voltage/temperature cutout FETs on it and it fits into that rounded end of the lower casing with the funny shaped circular air vents in the bottom. The other end of the casing houses the battery life gauge thingo. The lipos are a tight fit, you couldn't go any bigger really. Not shown but I put some thin rubber sheet between the cells and the PCB.

This pic is showing the stock 10x 18650 layout (with the China scrap cells) in their holding cage. I de-soldered it from the PCB.
http://db.tt/zaXPWnSf

How about a writeup please?

At least some better pics of the battery connections. i would love to do this mod to run my rattle gun a bit longer.