Are multi-chemistry chargers a poor choice for NiMH?

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iflo
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Are multi-chemistry chargers a poor choice for NiMH?

I was excited to move from a standard consumer charger for my AA/AAA NiMH batteries (mostly Eneloop and Ikea Ladda). Some of my batteries are nearing 10 years old, so I was looking for something that would be able to analyze as well as charge—an analyzing charger.

After reading through a lot of reviews, I decided on an XTAR VC4SL (I have some styluses that I want to get AAAA rechargeables for as well, so I was looking for a charger that could handle that size). I figured having Li-On support would be a bonus in case I ever started getting those types of cells.

I noticed that some of my batteries were only charging for a short time compared to others from the same batch, used in the same application. Roughly half of the batteries I charged (4 at a time) were only charging for 25 to 50% of the time that the others were charging. Sometimes, if I pulled those out and put them back in, they would “resume” charging for what seems like the full time, and other times, they would just stop charging again.

I noticed that this thread https://budgetlightforum.com/node/80060 had comments from another user experiencing something similar, and another user suggested that multi-chemistry chargers have rudimentary support for NiMH.

I wish I had known about this issue earlier. Frustrated, I contacted XTAR, and they confirmed that there may be incompatibilities with NiMH, and Eneloop and Ladda batteries can’t reliably be used with this charger. I’m quite upset that they advertise NiMH support if they know there are issues with popular brands like Eneloop and Ladda.

So it looks like I will be selling my VC4SL. But when I go looking for a new charger, is it true that multi-chemistry chargers are not a good choice for NiMH? I see great reviews for multi-chemistry chargers like the MC3000 and Opus chargers, but am I going to be disappointed if my main application is NiMH? What do people recommend for 4-slot NiMH analyzing chargers?

Edited by: iflo on 06/23/2022 - 19:49
raccoon city
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I have a bunch of Nitecore universal chargers.

They seem to charge NiMH just fine.  :THUMBS-UP:

mitsuki08
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I use the Liitokala Lii-500 for nimh and works fine.

Ventsi
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I had some issues with my older Xtar charger model X2. I was charging batteries until 4.0-4.1 volts, then putting it in my Olights and they’d show orange light just a few minutes after starting to use them. I thought the indicator in the switch might be a bit too sensitive, but then I realized this charger just shows different voltage than my old Nitecore D2 and my newer Xtar VC4SL, also different than the cheap voltmeter I have at home.
The VC4SL has problems of its own of course, like detecting NiMh batteri as Li-ion, plus other stuff that people mention. Unfortunately I’d have to say goodbye to Xtar chargers due to these reasons and I was wondering what are good alternatives with decent build quality and nice large displays to show a bunch of data about the batteries?

Marc E
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This isn’t a known general issue with multi-chemistry chargers.
There is a member here, HKJ, who performs quite comprehensive tests on chargers which includes NiMH charging, and many of the multi-chemistyr chargers perform well with NiMH.

You can explore the tests here and make up your own mind Smile
https://lygte-info.dk/info/indexBatteriesAndChargers%20UK.html

Ventsi
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I’m well aware of HKJ, thanks. Most, if not all of my batteries/charger purchases are based on his reviews.
However his review of the X2 doesn’t mention anything about wrong voltage. I might have a faulty unit of course.

Johnny_Bravo
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HJK don´t check all possibilities, so it´s maybe a compatibilty problem with the charger and cells.

However, maybe Xtar was good in the past but is IMHO overrated 2day. the VC4SL is unusable, the Dragon is also not worth it´s money.

About multi chemistry loaders, most of it are LiIon-chargers with added NiMH-charging and NiMH is more complicated to charge because of it´s properties. The only exception AFAIK is the Opus BT-C3100 which is based on a NiMH-charger with added LiIon-charging.

I have also some multi chemistry loaders like the Vapcell S4, it´s also a good charger for NiMH. I don´t see any pure NiMH-charger wihich is really better than the S4+. At HJK you will also find many multi chemistry loaders which are good on all chemistries. I also have the Accupower IQ338XL which works also good with different chemistries (but t´s not reliable in my experience, after some years the bays gave up)

Some say if a good cell is used most chargers will do a good job

flydiver
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There are some differences between chargers. If some particular feature is critical to you, then you need to weigh that.

In your case you have some really old NiMh. Internal resistance goes UP/worse with age and use, and capacity goes down. As it does the termination algorithm for ANY charger becomes more ‘challenging’. It becomes a problem with early or non-termination.

Having a decent analyzing charger can help you sort that out.
Another BUT – when the batteries get REALLY toasted the analyzing charger starts misbehaving too. And, you can’t entirely depend on the accuracy of the IR tests on slider style chargers. They can be ‘relatively’ useful, picking up big swings between good/OK/Lousy, but not highly accurate or repeatable. I have a Litokala 500 (I’ve had 3) ALL of them are useless for IR testing NiMh, but work for Li. Overall, a pretty good charger. Best charger I have for IR is a Zanflare. IMO the best overall analyzing charger I’ve used is the Opus BTC-3100 due to the wide settings you can apply, once you understand WHY and how to apply them.

For more accurate capacity and IR testing I finally got one of these: https://www.sevarg.net/2016/01/31/zb206-battery-tester/
With this: https://www.ebay.com/itm/122811259804?hash=item1c981f1b9c:g:KlYAAOSwiBJa...

MUCH more accurate and reliable. For reference capacity and IR testing I use it exclusively now.

To Air is Human, to Respire….Divine.

alpg88
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Depends on a charger and cells, some will not terminate charge properly, i had 2 such smart chargers that would shut off too soon, and charge only 1/3 of capacity, so i used dumb timed charger, other cells charged fine in those smart chargers. one of those was a cheap 6 bay charger, another very expensive hobby charger hitek x4. it just would not catch delta V properly with tenergy cells, but eneloops it charged fully. 

zoulas
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Nothing wrong with multi chemistry chargers however if all you want to charge is nimh AA/AAA then the Maha is the preferred choice. This company has been doing this for over 20 years. They are the best.

iflo
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Today my VC4SL detected a NiMH as LiON. Luckily I was watching it and saw it relatively quickly. I hope it didn’t damage the battery. I popped it out and re-inserted it and it then correctly detected it as NiMH. This charger is really worrying me!

Johnny_Bravo
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It´s the most awful charger I ever had in over 30 years with chargers