I currently have an Energizer CHFC2. It's the only one I have that will charge just one battery without another in the adjacent slot(which comes in handy when you have devices that take an odd number of batteries)

It apparently is supposed to be able to "reject" batteries that will no longer accept a charge. However, I have had several times where the bar graph will go up to "full" in the normal amount of time and stop there, and I'm none the wiser till I try to USE said batteries only to find that they have no charge. They do, if I remove them right away, but not if I leave them sit as "always ready" spares. And no, I don't leave batteries on charge for weeks / months, I remove them at least a few days after. But for some of my devices (like game controllers) I do want to be able to grab batteries I know are ready.

What is perplexing is how the charger fails to detect that the battery is self-discharging while still connected and throw a "bad battery" indicator, when it already has to detect the voltage to be a "smart" charger that stops so as not to fry the battery. (Not dangerous for nickel based batteries, just a major annoyance for the end user, especially if the maximum time doesn't allow for overnight charging)

Even better, it has a separate indicator for "bad battery" that has actually come on before, so I know it's not just a sticker placed there to make it look "smarter" than it actually is. Not sure if the charger has just gone faulty, but it's not as though it's consistently failing to charge any batteries.

I don't need C or D charging ability anymore - I just don't have anything left that takes those, and I have those plastic spacer tubes to fit AAs if needed for restoring / testing an old device. But I do want the ability to charge single cells, not just pairs, and it should have the ability to at least say "bad battery" if it's bad.

Anyone have a good experience with something that's either still made, or its longevity / serviceability is such that I'd still be able to find a working one?

 

Don't know of a charger that does that, but if you check an NiMH battery's open-circuit voltage with a multimeter, it should be a little over 1.3V when fully charged (mine measure about 1.32-1.33V).
That's how I check my batteries and it seems to be reliable, even when they've sat unused for a period of time after charging.

 

Anyone have a good experience with something that's either still made, or its longevity / serviceability is such that I'd still be able to find a working one?

I've had good luck with a Basen B04 charger, USB powered. It charges NiCd, NiMH, and Li-ion batteries. It even charges NiMH batteries that another charger flags as bad.

I've been using it for around 6 years now.

 

Don't know of a charger that does that, but if you check an NiMH battery's open-circuit voltage with a multimeter, it should be a little over 1.3V when fully charged.
That's how I check my batteries.

I actually had a load tester, once upon a time. I built it with an Arduino, and once it read the open circuit voltage it would automatically switch on a load resistor and measure the drop, illuminating a red, yellow or green light. You could select between low or high current mode, and also check 3V coin cells or 9V batteries. It wouldn't let you try the "heavy load" for the 1.5V batteries on the 9V battery, specifically to prevent that resistor from frying.

By the time it eventually failed, my parents didn't need it because they have few devices anymore that take AAs or AAAs, and those that do have such little current draw that the "load drop" is less of a concern. So I might just do a 555 timer thing that turns the load on/off, and set it up for me to watch the multimeter manually. Or, if I have the parts on hand to do so, just recreate my Arduino "automated" tester. It just had a pair of wires so as not to have to deal with multiple types of battery holders. Once set to the correct battery type, it would automatically read the voltage, switch the load on and then read it again, illuminating the appropriate light. It also had a "wrong connection" light to tell you that you did something wrong if it read more than 1.5V when set to test 1.5V batteries - and it would refuse to activate the "heavy load" resistor, as mentioned above.

 

I built it with an Arduino, and once it read the open circuit voltage it would automatically switch on a load resistor

I find that a loaded voltage test is not generally needed if the battery usage is for a low current device.

 

I currently have an Energizer CHFC2. It's the only one I have that will charge just one battery without another in the adjacent slot(which comes in handy when you have devices that take an odd number of batteries)

It apparently is supposed to be able to "reject" batteries that will no longer accept a charge. However, I have had several times where the bar graph will go up to "full" in the normal amount of time and stop there, and I'm none the wiser till I try to USE said batteries only to find that they have no charge. They do, if I remove them right away, but not if I leave them sit as "always ready" spares. And no, I don't leave batteries on charge for weeks / months, I remove them at least a few days after. But for some of my devices (like game controllers) I do want to be able to grab batteries I know are ready.

What is perplexing is how the charger fails to detect that the battery is self-discharging while still connected and throw a "bad battery" indicator, when it already has to detect the voltage to be a "smart" charger that stops so as not to fry the battery. (Not dangerous for nickel based batteries, just a major annoyance for the end user, especially if the maximum time doesn't allow for overnight charging)

Even better, it has a separate indicator for "bad battery" that has actually come on before, so I know it's not just a sticker placed there to make it look "smarter" than it actually is. Not sure if the charger has just gone faulty, but it's not as though it's consistently failing to charge any batteries.

I don't need C or D charging ability anymore - I just don't have anything left that takes those, and I have those plastic spacer tubes to fit AAs if needed for restoring / testing an old device. But I do want the ability to charge single cells, not just pairs, and it should have the ability to at least say "bad battery" if it's bad.

Anyone have a good experience with something that's either still made, or its longevity / serviceability is such that I'd still be able to find a working one?

These are good, each battery has a charger built into it, I have AA and AAA.



https://www.amazon.com/dp/B0CFT759FP?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_8&th=1

 

These are good, each battery has a charger built into it, I have AA and AAA.

The self discharge rate of that type of battery is horrendous. I have about 8 of the 9V variants and they self discharge in a couple months even if they're not used.

 

These are good, each battery has a charger built into it, I have AA and AAA.

https://www.amazon.com/dp/B0CFT759FP?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_8&th=1

What's their advantage?
They are way more expensive and have a lower Ah rating of 750mAh as compared to an AAA NiMH battery which can go up to 1000mAh.

Edit: Of course their Wh rating is comparable, but there's still the big cost difference.
The only advantage I see is if you really need 1.5V for the device where it doesn't work well or cuts off with 1.2V.

 

What's their advantage?
They are way more expensive and have a lower Ah rating of 750mAh as compared to an AAA NiMH battery which can go up to 1000mAh.

Edit: Of course their Wh rating is comparable, but there's still the big cost difference.
The only advantage I see is if you really need 1.5V for the device where it doesn't work well or cuts off with 1.2V.

As you pointed out, they're a steady 1.5v (like alkaline) rather than a declining 1.2v of NiMh, that was why I bought a few of them, its certainly worth having a few around, I get a brighter light from my LED flashlights because the voltage of four of them is higher 6v vs 4.8v



https://uniross.com/lithium-1-5v-vs-nimh-1-2v-rechargeable-batteries-which-one-is-better/

 

The self discharge rate of that type of battery is horrendous. I have about 8 of the 9V variants and they self discharge in a couple months even if they're not used.

Yes, there are pros/cons I know. I have a bunch of Eneloop batteries too, these have a very long shelf life.