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Battery revamp is worth doing

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hpc12 Page Icon Posted 2020-10-25 3:34 AM
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hpcboy - 2020-10-15 6:59 AM

Several days ago I replaced the old cells in my Jornada 720's standard battery packs. The official data says it's 1,500 mAh, but I read elsewhere that those Sony cells (US18650S) are actually about 1,300 mAh only. Anyhow, after revamping the battery, I kept using it every day with several programs running at the same time (writing notes and journals, playing audiobooks, opening resco explorer, playing PocketSlay, syncing and copying files on the cradle without AC etc.) until the power dried up after 16 hours 25 minutes.



This is the very first charging of the new cells (Sanyo, 3400 mAh, less than USD$5 each). I suppose repeating the complete charge-discharge cycles a couple of time can push the battery life even further.

I would say the most worth doing hardware mod on these old buddies is recelling the pack. It's rather simple and quick. It would be safe enough as long as you don't use soldering and sharp knives on the cells themselves (with a pair of reasonably steady hands and well-focused eyes of course).

The whole operations for both my Sigmarion III and Jornada 720 are documented here:
https://solochampion.blogspot.com/2020/10/book-of-sigmarion-iii-chap...
https://solochampion.blogspot.com/2020/10/book-of-jornada-chapter-2-...



Currently doing the MobilePro 900, which had a capacity of about 3 minutes, after charging to full almost immediately.



It came with the following batteries:

https://secondlifestorage.com/showthread.php?tid=1686

When doing this, did you use Tabbed, Flat-top, or Button-top 18650s?

Got my eye on Sanyo NCR 18650GA, but they come in three different types.

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hpcboy Page Icon Posted 2020-10-25 5:28 AM
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My observations (correct me if I am wrong):
Positive terminal (top): Each (large) brand has their own different tops (see the pic). They should be clean, no marks or dents. I don't have any flat top cells. I am not very sure if they are less standard.
Negative terminal (bottom): Should be all flat without bump/ring/plate/etc, and clean. Many scratches and marks may suggest that the cells have some hidden secrets that don't want you to know.
Rust means the cells are very old.
Tabs can be helpful for you to make the connection. But I'd prefer not to buy ones with them because the tabs may cover the top or the bottom so you may not be able to examine the terminals closely enough. The tabs may also add to the length of the connected cells. Sometimes the space within some casing can be so tight that even 1mm matters. And if you are careful enough when removing the old cells, you should be able to reuse the original tabs and wires without doing any extra work.


Edited by hpcboy 2020-10-25 5:33 AM
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hpcboy Page Icon Posted 2020-10-25 5:50 AM
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By the way, since I do it without soldering, to fixate the cells and the connections I use masking tapes instead of wire/cable tapes. The former is cleaner, easier to apply and remove, and lasting, whereas the latter can become sticky and dirty over time, and (much) harder to remove.

Edited by hpcboy 2020-10-25 5:51 AM
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hpc12 Page Icon Posted 2020-10-25 6:41 AM
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hpcboy - 2020-10-25 5:28 AM

My observations (correct me if I am wrong):
Positive terminal (top): Each (large) brand has their own different tops (see the pic). They should be clean, no marks or dents. I don't have any flat top cells. I am not very sure if they are less standard.
Negative terminal (bottom): Should be all flat without bump/ring/plate/etc, and clean. Many scratches and marks may suggest that the cells have some hidden secrets that don't want you to know.
Rust means the cells are very old.
Tabs can be helpful for you to make the connection. But I'd prefer not to buy ones with them because the tabs may cover the top or the bottom so you may not be able to examine the terminals closely enough. The tabs may also add to the length of the connected cells. Sometimes the space within some casing can be so tight that even 1mm matters. And if you are careful enough when removing the old cells, you should be able to reuse the original tabs and wires without doing any extra work.


Appreciate it. Mine appear to have the "LG Chem" tops:



I was exceedingly careful when removing the board, and the connections from the batteries. There may have been a little damage to the tabs when removing the spot-welds, but I'm confident they can easily be soldered back.

It looks like the LG MJ1 suits this purpose better, owing to having the same type of top.

On the bottom they are completely flat, and with the tab in the middle that connects the two batteries, it appears there is very little room for movement, so I'll avoid the tabbed versions.



Are batteries on eBAY in as poor a state as Compact Flash cards? (i.e. rampant counterfeiting?) or is the battery market simply saturated with genuine 18650 cells?
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hpcboy Page Icon Posted 2020-10-25 7:37 AM
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I don't buy cells online. eBay sellers can be hit or miss, even more so for AliExpress. Complaints and requests for refunding always feel to much to me. I always go to actual shops. My personal opinion is that shops which sell many genuine brand products, professional equipment and torches, etc. (and with customers frequenting regularly), would be signs of a reliable seller.

My shopping tactics: Examine the appearance of cells carefully, ask the seller some "dumb" questions to see how much they can tell you, then before paying ask the seller to do some simple testing with a multimeter on the spot, perhaps even buy a quality and reasonably priced charger/discharger for yourself to do more home testing.

To tell fakes from genuine cells, weight is the least reliable (unless the cells are clearly over/underweight). Looks can be deceiving from time to time (esp. online images). Usually except for expensive professional products (like those for very strong lights and torches), generally the wrapping of these cells is very dull looking and contains nothing more than a model number (or a QR code for some models).

To begin, buy just a couple of cells for one battery pack first. If the result is great after recelling that pack, then you know where to get more next time.

I find this article a good read, despite its focusing on Samsung 25R cells (my pic above was linked from there).
https://batterybro.com/blogs/18650-wholesale-battery-reviews/3082886...
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hpcboy Page Icon Posted 2020-10-25 8:02 AM
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hpc12 - 2020-10-26 1:41 AM
I was exceedingly careful when removing the board, and the connections from the batteries. There may have been a little damage to the tabs when removing the spot-welds, but I'm confident they can easily be soldered back.


Soldering on the cells is what I won't (and dare not) do. Plus replacing soldered cells later on is more challenging than taped/(hot-)glued ones.

It takes a bit longer but is actually easier to work one welded spot instead of several at a time.

Edited by hpcboy 2020-10-25 8:05 AM
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C:Amie Page Icon Posted 2020-10-25 12:26 PM
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Soldering them is fine, you just need low heat soulder and to be quick about it. You need to ensure a good, safe connection. After all, they are usually spot welded!
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_dev-null Page Icon Posted 2020-10-25 3:51 PM
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Hi!
I also put new cells in my Jornada, sadly i didnt watch out for the right diameter and orderen Samsung cells which are slightly thicker than the original ones. Dont hit me for that, but i took out my Dremel and grinded away a little bit off the inner housing - and voila it fits. I currently make a cad drawing for the rubber feets. I like to print them with TPU.

Soldering should be done very carfully without too much heat.

Stefan
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hpcboy Page Icon Posted 2020-10-26 12:00 AM
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I just have a regular solder which is not a low heat one. Ane I'm afraid I won't be fast enough as heat seems to transmit to and build up in the metallic cells pretty quickly. I was once considering buying a small battery spot welder but gave up the idea because the cells are now taped firmly with each other and with the connectors and there is no room for them to rock inside.
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hpcboy Page Icon Posted 2020-10-26 10:16 AM
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hpcboy - 2020-10-26 12:28 AM
...Positive terminal (top): Each (large) brand has their own different tops (see the pic). They should be clean, no marks or dents. I don't have
any flat top cells. I am not very sure if they are less standard....


Found a typo: I should've typed "button" (for 18650), which doesn't seem very common inside laptop batteries. Most are flat tops.
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Rich Hawley Page Icon Posted 2020-10-26 10:38 AM
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I'm lucky I guess. There is a Vape shop about 1/2 mile from my house. The guy sells 18650s there at cost. And since he buys in bulk, they end up costing me about 2 bucks each.

And I tested them...here is the 3000mAh rated actually measured..



(20201023_173144.jpg)



Attachments
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Attachments 20201023_173144.jpg (2256KB - 0 downloads)
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hpcboy Page Icon Posted 2020-10-26 12:30 PM
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Nice deal!

I also bought another pair of Sanyo cells to rebuild another Jornada pack.
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hpcboy Page Icon Posted 2020-10-27 5:11 PM
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Just finished recelling the spare aging (15+ years) battery pack for my Jornada 720. It took only about 10 minutes to get everything done. Same kind of Sanyo NCR18650 "B" grade cells.



Now with both revamped packs I can get 30+ hours of runtime.


Edited by hpcboy 2020-10-27 5:12 PM
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stingraze Page Icon Posted 2020-10-28 9:34 AM
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hpcboy - 2020-10-28 2:11 AM
Now with both revamped packs I can get 30+ hours of runtime.


Really? 30+ hours? neat... None of my laptops (even Sigmarion 3) run that long lol.
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C:Amie Page Icon Posted 2020-10-28 9:54 AM
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That's the promise of the new ARM replacements for x86 laptops. 16-20 hours in the next couple of years. Yet we could have had it back in 1998.
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