How much is the battery charger and tester worth?

softdown

This unit cost about $50 more than their base unit. But it includes 2.2 pounds of nickel plated strip and a built in battery tester and charger with alligator clips. If you endeavor to do real work with 18650 lithium batteries you should be able to test and charge them - with alligator clips for flexibility. 

Battery chargers and testers is not something I seek to study a lot at the moment. Too many eggs to fry already.

https://www.amazon.com/Mophorn-Battery-Soldering-Portable-Batteries/dp/B07SYLH84B/ref=sr_1_24?dchild=1&keywords=spot+welder+battery&qid=1596122721&sr=8-24#customerReviews

BB.

This guy posts (out of Denmark) on Candle Power Forums and has done a bunch of testing/reviews/articles about battery chargers and batteries (smaller batteries for "flashlights and such", not large format batteries/chargers):

https://lygte-info.dk/
https://lygte-info.dk/info/indexArticles%20UK.html
https://www.candlepowerforums.com/vb/forum.php

My own little bit of testing and such... I have a charger (for single round NiMH and Lithium cells) that can test batteries (capacity measurements and internal resistance)... And, for me, the big issue has been self discharge.

And for me, the tester did not really do say anything about the battery's ability to keep a charge (for at least one year and 80% State of Charge), vs dying in weeks or less.

-Bill

softdown

Rechargeable lithium battery packs are unlikely to  "keep a charge (for at least one year and 80%" - in my estimation. 

Been watching  a lot of podcasts. Have not seen anything about measuring the self discharge rate. 

Keep them cool if possible - we all know that.

Edited - meant packs, not singles.

softdown

Single 18650s stored cool keep their charge for years in my experience. Battery packs? Unplug from tool if it will not be used for a couple months. Which will ensure its use very soon - of course.

mike95490

I had a fancy universal charger years ago, that used magnetic electrodes, since most connector surfaces were nickel plate steel, the magnets would stick right on, even the weird shaped stuff

softdown

mike95490 said:

I had a fancy universal charger years ago, that used magnetic electrodes, since most connector surfaces were nickel plate steel, the magnets would stick right on, even the weird shaped stuff

Might be able to spot weld magnets on? Just bought this. 1/2 price due to big cosmetic blem. 
https://www.amazon.com/gp/product/B07DKD3LRF/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

BB.

Li Ion, in general, have very low self discharge rate.

NiMH batteries... They did not hold any charge past a year or two... The low self discharge NiMH batteries (such as Eneloops) do hold at least 80% of their charge after 1 year IMHO.

The low self discharge NiMH batteries are sometimes labeled as "precharged" batteries for other brands.

-Billl

Photowhit

BB. said:

NiMH batteries... They did not hold any charge past a year or two... The low self discharge NiMH batteries (such as Eneloops) do hold at least 80% of their charge after 1 year IMHO.

The low self discharge NiMH batteries are sometimes labeled as "precharged" batteries for other brands.

The reason for them being labeled as "precharged" is because they came "precharged". Usually "AA" NiMH batteries came with a tiny/unusable charge on them and had to be charged prior to use. I use to use a lot of them. I now again use a lot of them as they became the replacement battery of choice for my DeWalt pod battery tools. I just charge them up the night before I intend to use them. After a month or so any charge on them would be minimal. But I could buy 2 replacement batteries for $24 vs $100 for a pair of real DeWalt NiCD batteries.

I guess it's been 2 years now and they are working fine, the first sett came with broken cases and they replaced the 2 batteries. I put the battery packs into old DeWalt or off brand cases and had 4 batteries, I've miss placed one but the other 3 are working well.

softdown

I plan to make a few Li Ion battery packs. A good charger and tester will be needed. Still seeking an evaluation of the above in question. 

What started as a simple quest to rejuvenate expired tool battery packs has expanded more than anticipated. There are both exciting possibilities and daunting challenges.