I have a 5 year old, wf-139 charger I believe. I do have a bunch of laptop pulls I have not charged for a while, and some good protected cells all 18650. I don’t want to try charging something in my house or garage that does not have much voltage in it. Is a good safe charger that will let me know the voltage something like a Liitokala Lii - 500? I want to buy something I can just pop the battery in, get a reading on the voltage, and if its too low, I can take it out immediately. Does this make sense to you? Will this set up work?
Visit the homepage of HKJ - the battery and charger guru:
http://www.lygte-info.dk/info/indexBatteriesAndChargers%20UK.html
He tests most chargers, which are available on the market and his tests are really good (at the end he wrote a conclusion, if the reviews have to much information and datasheets for you).
I use the Opus BT-C3100 (version 2.1) and XTAR VP2 (both have a display, which shows the voltage).
I have lurked extensively. I have e been on HKJs page many times. I don’t know if the model I mentioned or the ones you did are better vs the other. HKJ does not lay it out that way. I’m concerned about safety. Is the way I’m thinking of testing my older cells is correct? Do I simply place them in the charger get a reading then take them out if low? Which charger out of the three mentioned are best and easiest for this? I’m looking at testing the voltage and charging them safely.
Did you measure them with a DMM?
I’m a newbie. I don’t have separate meters. I have some batteries I have I have not charged for a while. My charger is old without a display. I want to buy a new one. And would like to know a simple process for making sure I charge them and if necessary test them first. I wasn’t sure if there was a charger that I could buy for around $30 or less that would do all if the safely. And if so would the charger tell me if the battery needed to be tossed as soon as I pop it in. Thanks in advance.
Maybe buy a DMM first.
You can use it to check the cells AND see if your chargers are doing a good job.
Yeah umm not seeing too much about that on here. I’m sure it makes sense. Was hoping I don’t have to get into meters. Was hoping someone can advise me if there are chargers that can safely help me address my question above. If not then I will have to learn about meters. I’m looking for a few simple steps with a simple product to determine whether to toss or keep a battery. Sorry I’m don’t have a lot of electronic expertise. I have read if the cell is less than 2.5V to toss it. Please give me a few easy steps with a simple product) charger and or meter)
Are you located in the US?
Yes I am in the US.
Illumn.com
Nitecore D2 or D4 will do what you want.
Better than opus 3100, vc4 or liiokata 500? Do I just out it in check voltage and if low pull it out quick?
Bugsy36 is giving you good advice.
I have the Lil 500 and the D4 and use the D4 much more often.
Both are good, I think it’s just my simple mind that prefers the Nitecore 
As he suggests, Illumn.com has the best price by far.
Thanks,
-Chuck
Thank you all. On the D4, as soon as I plug it in, it would tell me the voltage. If it’s low like less than 2.5V should I toss it?
I would almost never suggest anyone go out and BUY a harbor frieght red meter since they basiclly give them away about 20% of the year BUT it’s gotta be better than nothing .If you catch one on sale for a few bucks or get a free one than I’d say having a crappy meter beats nothing . not much of a reccomandation I know …just sayin’
If you’re really concerned about SAFETY I’d say screwing around with laptop packs with no meter is a bad idea …
Why do it when great battery deals have been so popular recently .
I’d suggest spending 20$ with Gearbest and maybe buy some LMR LG or samungs …
I’m all for laptop packs but not going into them blind…
not having any meter is like giving your kids steak knives to eat with instead of silverware .
or
you want to teach them to juggle chainsaws …safely .
I’m juggling the thought … /Good cells in a bad charger or bad cells in a better charger ….(no meter ?)…it all seems a lil crazy
Sure I have a mixed bag of batteries. But I will buy a Harbor Freight meter. What is the limit I should use to throw it out if it’s under a certain reading?
Nice, when you select DC voltage you can’t mess measuring up, if you see a - in front of the reading just switch the probes.
It is my understanding 2,6v is the minimum but I have no experience with this but you surely get the correct numbers later
Edit thanks for the correct number!
Buy a multimeter, it’s very easy to use. Use it on the battery, and if it’s less than 2.6V, discard the battery.
This is what I needed. Thanks
This is a big help. Thanks so much to all of you that responded.
I got my cheapo dmm, from Harbor Freight for $6. All of my batteries were 3.9 - 4.1V. Thank you all.