Tool batteries: experience in lithium VS

Batteries, Chargers, and Battery Management Systems.
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nutspecial
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Tool batteries: experience in lithium VS

Post by nutspecial » Fri Mar 18, 2016 2:45 am

. . . . VS anything you want, but I'm mainly considering one generation back : nicad . .

Lithium has many benefits in terms of power density, (etc?). But are there comparative shortcomings of added complexity, availability, price, longevity, ecosound, etc to other similarly used batts?

Here is another thread 'tool batteries'. As always, mods have my approval to combine. I am also seeking readers' knowledge and experience on lithium vs xxxx, and sharing my recent 'escapades' with my:
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The reason I'm questioning is because I have my 2yo bosch 18v Li ripped apart to recharge. Both 2ah packs failed to charge right around the expiration of the 2yr warranty, so I'll take matters into my own hands.

I've only used these to a marginal extent, and was careful to keep them out of high heat and keep a median charge level over their life. The main issue with one about a year ago was getting slightly wet from a spray/mist which must have compromised part of the 'brain'
I pulled it apart and wire brushed the pcb of oxidation from dirt and moisture while live :shock: . A no-no, but afterwards the pack continued to work another year and longer than it's twin, with the exception of the led batt level meter "fuel gauge". I assume I ruined part of board, but any bms function was apparently retained.

Anyway, both are now 'dead' :evil: , which I attribute mostly to bms/pcm drain over a few months? The first pack was sitting at about .3v /cell - 1.5v /pack, after 3 months of dormancy. The temp was ~50deg F and I left the pack @ 50% soc afaik.
Imo this seems a fairly sad drop, and am now recharging the 5s with my 'gophert' adj supply, which is highly handy for an entry hobbiest imo. They are talked about and linked in the 'forget meanwell' thread

I set the PS to .3a and slowly bumped voltage from the 1.5v toward 18v.
Running up @ .5v per 1-2sec, PS stayed in CV mode with the battery not needing much of that .3a.
CC started to kick in around 9v, so I assessed voltage climb rate was slow enough @ .3a to not harm the cells. It took around 5min to climb to my setting of 16v. @ >3v /cell, I upped amperage close to 1a for the 2ah 1p cells until >17v, where the pack finally registered again on the stock bosch charger.


Hopefully both packs revive and last alot longer, because my much older bosch nicads are still very usable, with lessened capacity likely due to slow dendrite formation. I've never had to pull them apart to revive, and they've been more water resistant.
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One day, I would like to consider using this apparently tried and true method of Nicad revival:

I also found this, which was N2M- Convert nicad/nimh tools to use lithium packs . .

And hopefully this is general principle I've applied to my bosch lithium.

Hillhater
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Re: Tool batteries: experience in lithium VS

Post by Hillhater » Fri Mar 18, 2016 6:34 am

I trust you aew checking individual cell voltages before and during charging , not just the pack voltage.
Otherwise you could have a dead cell in there causing you to overcharge all the others.
This forum owes its existence to Justin of ebikes.ca

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nutspecial
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Re: Tool batteries: experience in lithium VS

Post by nutspecial » Fri Mar 18, 2016 4:59 pm

Yessiree, good to keep an eye on individual cells.
I only checked the convenient three of five cells a few times while bringing them from .3 - 3.5v cell /1.5- 17.5v pack before using the stock charger, but indvid cells corresponded 5x to pack level. Will be keeping an eye on the pack though, of course. I honestly have no idea the level of bms these things use.

Also, I got into the 2nd pack and it was sitting @ 17v, just under where charger accepts. 20sec @ 1amp raised it enough to charger normally. That one must have been the pack I used most recently ~ 4 months ago.

The lower pack (.3/cell) must have been the one that quit a few months before that. Still surprised it was that low, and that cells were balanced way down there. Will update.

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Re: Tool batteries: experience in lithium VS

Post by nutspecial » Wed Nov 08, 2017 5:55 am

*****************PASS IT ALONG*********************************

There's gonna be some of these available, if you keep your EYES open
^^^^ that's a hint-- (but the only one you'll get from me right now. . . .) :D

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(I currently have four (lightly used) for testing, and hopeful use for 10ah 36v pack . . )

____________
BTW 36v 9s works GREAT for the stock ebay hub winds (whatever that is) when they're in a 29'er or fatbike wheel, for about 30-33mph topspeed. . . . . Also very nice for 'vintage' direct drive 24v bikes like the Ezip and Izip.

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