I’ve recently purchased a very nice made in USA Sunstone Engineering battery spotwelder.
I was wondering If anyone has some battery packs they would be interested in me rebuilding? (USA only at this time).
I’ve successfully rebuilt several power tool and flashlight battery packs. Some of the power tool packs I’ve rebuilt (on an older battery spot welder) are still going strong after 2 years. I can rebuild quite a few packs, but there are some packs however that are difficult or impossible to rebuild (most laptop packs, or anything that is ultrasonic welded shut). But I would say there are a good portion of pack for flashlights and other electronic devices that I could rebuilt for a lower cost than buying a replacement pack.
You would also have your choice over what cells are used, and often times we could significantly upgrade the battery packs capacity as well. Generally speaking all pack rebuilds would involve replacing every single cell with new ones. Packs will often use low end 2200mAh cells could be replaced with brand new 2600, 3200, 3400 or 3500mAh 18650s for example. I have all the gear to test and charge almost any kind of battery. Electronic load for discharge tests, Internal Resistance meter, Digital bench power supplies, chargers, several multimeters etc. I could also build custom packs for custom projects. I would probably have to order a BMS or proper balancing plugs however. I have a large number of brand new 18650 cells in stock, but also have new Eneloop AAA and AA’s. Other odd cell sizes are probably possible but would probably have to be ordered.
Please note that with some battery pack rebuilds, it is possible that you send in your pack, and I would discover its not possible to rebuild that type of pack. Or its possible that the proprietary BMS board has gone out, and a replacement board is not available. But in these cases, I wouldn’t charge anything (you would just lose out on the shipping costs of the pack, and it then could be either recycled or return to you).
Anyways, if anyone is interested feel free to send me a PM. For the first few 5 or so interested BLF’ers I would offer my rebuild service at a very low price.
I am guessing the resounding silence is giving you a hint.
Just a (presumably helpful) thought or two about the idea. I may hit something you have not thought about. Have you taken a look at the entire financial impact of a rebuilder that is not local?
- Shipping both ways for heavy and odd sized items.
- Are you fixing a pack or completely replacing all the cells - I feel the latter is required and probably your intent
- Sufficient payment for you time. The difference between a hobby and a business; don't short yourself.
- Markup on batteries.
- If you can't get home delivery and pickup for everything, cost to go to the carrier. For home location, can you provide sufficient security for packages.
- You need to be able to be certain which packs you can rebuild. Mistakes will cost you money. Return shipping + compensating the really annoyed potential customer.
- Potential licensing in your state and collecting required taxes.
- You appear to have the tools, so you can consider that a depreciated sunk cost. If they are in good enough condition to be a long term reliable tool.
The last two are obviously in you control. But the entire stack is what it will cost the customer. How will it compare with just getting a new pack who's quality they can depend upon.
If applicable, the WAF and all the packages.
I hope you are able to evaluate your idea and can make some money.
I’m in, because I already checked with commercial rebuilders, who say they don’t do the battery packs I have (and the radio is emeritus)
The commercial rebuilders recommend buying third party replacements.
And I did a couple — yeah, third party packs are cheap, but the problem is, I suspect they’re cheap inside too.
(I can find third party packs for anywhere between $18 and $50 apiece online, plus shipping)
So I’m going to try this out.
Being able to know what cells I’m getting (Eneloops!) is a real advantage here, assuming this works out.
All I’m risking is $5 to ship a couple of NiCd battery packs I’d otherwise be recycling — to have a shot at buying them back as two good quality NiMH packs.
If it doesn’t work out he can recycle them.
Yeah, I hacksawed into the corner and pried both cases apart, so I and he know what’s inside them
No silence here, I’ve exchanged half a dozen PM’s from multiple members. There are many places where I plan to advertise my services, so I’m not concerned that this thread isn’t flooded with dozens of rebuild requests.
I’ve considered pretty much all the things you mentioned already, and I’ll address most of them.
1) Shipping both ways. Not a big deal, some packs might cost as low as $2-3 to send, others $5-10 each way. The fact is that finding a local rebuilder that actually deals with Li-ion is probably next to impossible for most people. Most local shops will rebuild Ni-Cd and Ni-mh and will charge you an arm and a leg for doing so. Most shops will also be very hesitant to rebuild any pack they’ve not seen before. There are situations where finding a replacement pack might be not available and a rebuild is the only option.
2) Fixing vs replacing cells. In 99% of situations, all cells would be replaced. In some situations however, I’ve had brand new out of the clamshell battery packs (a black & Decker 36v Li-ion pack for example) that was DOA. I opened it up and found one cell was defective, and the rest of the cells were in perfect condition. I had multiples of these packs, so I ended up cannibalizing them and removing known good new cells from another pack with 1 dead cell, in order to make a perfectly functioning pack. Since the cells were all new, the same model, and had the same resistance (within 5%) it was safe and viable to do that in that situation, and that pack is still working great after a couple years of regular use.
3) Hobby vs Business. My hobbies have become my business. Pack building is some-what of a new venture for me, but is well worth my time. I don’t mind offering to rebuild a few packs for BLF’ers at a significant discount. I have other larger commercial production uses for my battery spot welder. Pack rebuilds are only going to be a small part of what I do. And I find it fun and rewarding to rebuild something and make it better than what it was, and knowing that I’m saving someone money in the process is a bonus!
4) Markup on batteries. For the first few BLF’ers i’m hardly if at all marking up the cells price. But yes, in the future, I would slightly mark up the cells cost as to be expected. I buy cells (1000+ at a time generally), and can still offer people great prices even with a slight markup.
5) Shipping and security is no problem. I’ve shipped well over 10,000 packages in the last few years. Over 20 packages sent out today alone. This is not new to me.
6) Which packs I can rebuild. I can look at the pack, and search for images and potentially find teardown pictures or other sellers offering rebuild services for that pack. If I can find that information, then with 90% certanty I can rebuild that pack. But I’m willing to do random “odds and ends” packs and give them a try. Due to some odd assembly methods and ultrasonic welded shut packs (usually in plastic cases) some packs may not be possible to rebuild. But I could generally predict that prior to having a customer send it in, or would warn him with something like “I may not be able to gain access to the cells in this pack due to the way its manufactured.” As I do more and more packs though, I’d build my own database of packs that I can do, and develop a list.
7) I’m an owner of my own LLC, I’ve been paying taxes, and have business licenses and collect sales tax for customers in my state. Have been doing this for roughly 5 years. This is nothing new to me, it is just a new part of my business.
Lastly regarding my quality vs new quality. I have the ability to greatly exceed the quality of most OEM packs. This is because I can chose better quality or higher capacity cells than originally used. Have a pack with generic Chinese 18650 2200mAh cells? No problem lets throw some Panasonic 3400’s in there!
I actually just rebuild two 3x18650 HID flashlight battery packs. The packs were 2200mAh originally and used generic Chinese cells. I ended up opting for NCR18650BE (10A) cells. The end result is significantly longer runtime and more than likely much longer cell life. A new pack from China would have been about $35. I was able to do it for a fair amount less than that, and use much higher quality and higher capacity cells. In situations where OEM packs are expensive, or the OEM uses low quality cells, a rebuild is a great option. There are some situations where OEM packs are cheap or there are readily available aftermarket quality replacements, so it would be not advisable to rebuild.
Hank and I have exchanged a few PM’s. His packs were in a plastic case, but since he was able to crack them open without damage, I feel conformable that I can do the rebuild. But yes, the quality difference between some generic Chinese ni-mh and ni-cd and a 2100 cycle LSD eneloop is night and day.
Well nothing a little hot glue or duct tape won’t cover up, and since I did the cracking open, I’ll have no worries about appearance.
(The trick for my sealed cases — Yaesu radio batteries, by the way — seems to be try to pop them with a vise (which I”’m told works but didn’t for me)
then very gently hacksaw through a corner ’til you just barely get through to inside air and then stop and go at it with a wedge/lever/screwdriver.
Cut any deeper and you’ll be sawing into a battery.)
Just a question with respect to rebuilding cordless tool battery packs using Eneloops.
Now that it has been a year, how well do the Eneloop packs work wrt to power and longevity?
I am asking because I don’t have any information if the low self-discharge property of Eneloops
affects their use and cycle lifetime when applied to high current applications.
I’m specifically interested in rebuilding my Ridgid 12v NiCd drill battery pack with Eneloops.
I’m still quite happy with the repacks used in our ham radios (quite a different issue).
It’s nice to pick them up every month or so, check, and find them working — as we’ll need them to do after the earthquake.
There really doesn’t seem much - even in the Google universe - about using Eneloops or other LSD batteries to rebuild
rechargeable tool battery packs. In my own case I’m out of luck anyhow because my battery packs take the SubC 4/5 cells
which are too small for AA-sized Eneloops.
Don’t think in terms of what used to be there. Think about the actual internal dimensions of the battery pack “case” that you have. Be creative in coming up with a solution. Even the AAA Eneloops are better than the 4/5 Sub-C NiCad cells that come with your pack, if you stuff enough of them in there! But, I think there are 4/5 Sub-C LSD NiMH cells available on some battery websites. They aren’t Eneloop, but maybe they’re pretty good. The singular advantage that a NiCad cell has is that it can stand a lot of abuse, including huge current draw. You’ll want to try to get as high current draw as you can somehow. In that case, three or four Eneloop AAA might be better than one NiMH 4/5 Sub-C of unknown origin.
re: 4/5 Sub-C LSD NiMH
Ultimately it has to be economical. I’ll have to see how much Sub-C LSD NiMH cost.
re: all about the space
Good point about AAA’s. Here in Canada, I have found the AmazonBasics LSD AAA to be excellent
value (I don’t know if they are as consistent and long lasting as proper Eneloops - time will tell with my batch).
If I can fit them into one of my Ridgid 12V packs it can be interesting. My Ridgid drill with 2 batteries is 8 years old
and one of the batteries only charges to ~9V. That’s my candidate to experiment with.
Pretty sure the Ridgid NiCd charger (from 2008) can handle NiMH.
Depending on how it’s built, it should have room for at least three and possibly four AAA for each 4/5 Sub-C to be replaced. Both the Eneloop and Amazon Basic white cells are 750mA capacity each. HKJ tested both of them up to 5A output. Eneloop edges out the Basics by very little at low current, but the spread gets bigger as current draw goes up. Still, the Basics should do well. The NiCad cells should be around 2.2A each. Three of your Basics would give you 2.25A, a little boost. If you can get 4x for each NiCad, you’ll have a capacity of 3A, which is much better. But, if your pack is rated 12V, it has 10 cells already, so a 4x replacement would be 40x Amazon Basic AAA cells! I hope they’re not too expensive!
I agree and understand, but wouldn’t another thing to consider is the charger, i.e., would the stock charger work, or would he need to some different charger?
It’s a matter of whether the charger was made to support both NiCad and NiMH packs. The voltage will be the same (you put x number of AAA cells in parallel for each Sub-C replaced). Only the capacity will be different/greater. So, it will take longer to charge, but a charge will last longer also.
sunjwd, have you researched what a replacement 4/5 Sub-C NiMH would cost? Since yours are so low capacity, it wouldn’t take Eneloop-grade cells to see a marked improvement.
Battery Junction has Tenergy 10511 NiMh 4/5 Sub C 2000mAh w/ TABS for $2.85USD each plus shipping if buying more than 6, which you would be. That would make it ~37.50CAD for 10 of them. I think Tenergy is a decent brand, and putting 4/5 Sub-C cells back in would be the easiest thing to do. They also have the same cell without tabs for a bit lower price. If you buy 20 of them, to do two battery packs, you’d be spending ~75CAD, and you’d get free shipping (over $50USD).
I did look at replacement 4/5 sub-C, both NiCd and NiMh. Free shipping from US vendors only applies to American customer addresses, and tends to be prohibitive to Canada. Batteries are heavy. In comparison, new Ridgid 12V NiCd packs from Amazon.ca are CDN $47 with free shipping in Canada.
I only asked about Eneloops because I’m a home user and it would be really great if the batteries still have charge when I need to use a drill.
My drill gets used probably once every couple of months.
(I’d called Ridgid customer care, but apparently they never did receive my Lifetime Warranty
registration card - so I can’t get my battery replaced. That burns as the lifetime warranty covering even batteries was the reason I bought Ridgid.)
