basic charger?

[paulr]

I'm surprised this seems so hard. What is a good compact NiMH charger without a lot of modes and parts? Basic requirements:

1) must be universal voltage (110/220) for travel.
2) must have independent channels to be able to charge cells from 1-cell lights
3) ultra miniaturization is not required but the idea is to have a smallish charger (2 cell or 4 cell is ok). Built-in AC flip-out prongs are nice. External power cube (wall wart) or brick is bad.
4) super fast (1C) charging is not required but should have (say) C/5 or faster, with automatic termination. Full charge longer than overnight (8 hours) is a pain.
5) Should be well made and not look like crap. Cost is not too much of an issue, within reason.

These goals wouldn't seem too hard to fulfill, but I'm having trouble finding anything that meets them. There was an Eneloop charger that did it but it seems to have been discontinued.

Suggestoins?

 

[TooManyGizmos]

Paul , Thomas Dist. has always had good choices ... have you looked there ?

 

[paulr]

Yes of course, though I guess I can check again. I do see batteryjunction has a few that look good from the specs, which of course don't necessarily tell the whole story. I was hoping to hear of experiences from actual cpf'ers.

 

[InHisName]

Your description matches one I am chasing. Duracell mobile (model 23) isn't carried in many places anymore since they have clearanced them out already. eBay sellers charging more than I want to pay so I am just standing by waiting for the next clearance sale to appear. Most eBay sellers want more than $20.

 

[PeAK]

Your description matches one I am chasing. Duracell mobile (model 23) isn't carried in many places anymore since they have clearanced them out already. eBay sellers charging more than I want to pay so I am just standing by waiting for the next clearance sale to appear. Most eBay sellers want more than $20.

Strange as that charger is available today at most of the big chain stores in Canada.

Back to the first post: For the purposes of travel, you could top up batteries each night as long as the termination is predictable and this would allow you to use a much lower charge rate unit. I've been very impressed with the Duracell Mini Charger (CEF20) that charges at a slightly lower 1/7 C rate but has the unusual ability to "not" heat batteries. It meets all of your other critierion.

The others that seem to fit are

1. CEF23 already mentioned and a forum favourite
2. Meijer/Camelion BC-905a (several threads here about it and one of my "go to" chargers.
3. Fuji 600LCD post: specs looks about right but not much experience here in the forum

Note: Do not assume that all 2 hour smart chargers are created equal. Some have better terminating algorithims than others...ditto for the 1/3/&4 hour chargers. Duracells seem to have had a string of cool and well terminating chargers.

 

[Mr Happy]

If you happen to come across one the Duracell CEF21 would meet your requirements for AA batteries. It is what I take with me when I travel. However it has termination trouble with AAA batteries so it would not be ideal if you use those.

 

[SilverFox]

Hello Paulr,

The Vanson V6000 looks very interesting...

Tom

 

[Robin24k]

If you happen to come across one the Duracell CEF21 would meet your requirements for AA batteries. It is what I take with me when I travel. However it has termination trouble with AAA batteries so it would not be ideal if you use those.

CEF21 might be hard to find, but the CEF23 would be my suggestion. If you have 4AA's in there, you can use it to charge USB devices. It's ~$17 from Ebay.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=380175101197

 

[paulr]

Thanks, that's interesting about the Duracell chargers. I didn't realize they had independent channels. I'm not buying from fleabay these days but I see some of those chargers at Walgreens, so I'll take a closer look and check what models they have.

Vanson V6000 looks like a nice charger, but large and with an external power cube.

 

[paulr]

Walgreens has the CEF-20. I'm having a little trouble understanding if that's different from the CEF-21. I see battery junction has some other promising units. Thanks everyone.

 

[PeAK]

Walgreens has the CEF-20. I'm having a little trouble understanding if that's different from the CEF-21. I see battery junction has some other promising units. Thanks everyone.

Have a look the Duracell product page. Both are smart and can charge a single battery. The CEF21 can charge 1 to 4 batteries independent at a 30% higher charge rate.

The CEF20 can charge one battery independently or two batteries in series.

 

[Mr Happy]

I was in Big Lots today and they still have a stock of CEF21 Power Gauge chargers at $16 each. If you take a look in this thread, the CEF21 can be modified to make it almost the perfect basic charger (it is already a fine charger without the modification). It meets all 5 of your criteria from post #1.

 

[paulr]

Have a look the Duracell product page. Both are smart and can charge a single battery. The CEF21 can charge 1 to 4 batteries independent at a 30% higher charge rate.

The CEF20 can charge one battery independently or two batteries in series.

Thanks, I'll look for a CEF21 then. Charging two batteries in series doesn't sound good if they are in differing states of charge, or maybe even different sizes (one AA and one AAA).

 

[PeAK]

Thanks, I'll look for a CEF21 then. Charging two batteries in series doesn't sound good if they are in differing states of charge, or maybe even different sizes (one AA and one AAA).

Charging in series is not that bad provided both are used/drain together and that they each be charged independently periodically to "reset" them both to full. I have "better chargers" but I can dumb down to this level for travel for the size advantage.

Do a search on the "Duracell Mobile Charger"/CEF23 in these forums as well as it is generally more available due to it's lower cost of manufacture than the CEF21. It charges at 500 mA for both formulations (0.25C for AA and 1/1.6 C for AAA). It also has 4 indpendent channels.

Last, although the CEF21 and CEF23 meet your technical requirements, they are not the smallest units. Drop by Meijer and see if they have any of their "intelligent Chargers" in stock...almost a clone of the Sanyo unit in both features and size.

 

[Locoboy5150]

I have a Titanium Innovations M-8800 charger for AA NiMh batteries and it works great.

http://www.batteryjunction.com/8800.html

It's very simple for guys like me that live by the K.I.S.S. principle. Plug it in, pop the AA cells in, leave it alone, it stops charging when the cells are fully charged. It has independent cell monitoring so you can charge anywhere from 1 to 8 cells in it with no problems. While not a dedicated travel charger, it is extremely compact for an 8 AA cell charger. I've taken it on several road trips and it it well made so it can handle the abuse of life on the road.

The M-8800 does not operate on 220 V-AC though. It only operates on 110 V-AC and 12 V-DC. That may not be a problem though if you already have a travel power converter. The 12 V-DC power option came in very handy throughout my road trips.

If you buy it from Battery Junction, they have a discount code for CPF members.

http://www.cpfmarketplace.com/mp/showthread.php?t=181841

 

[PeAK]

I have a Titanium Innovations M-8800 charger for AA NiMh batteries and it works great...

The term "works great" needs to be qualified by commenting on gauging predictable termination and the temperature of the batteries at the point of termination.

Recently, the CEF21 was modded for improved termination. While things generally improved, the type of battery was also just as or more important (also see Energizer 2500 thread). That being said, smart chargers are not all created equal and some gernerate much less battery heating than others...they're referred to as gentle.

...Do a search on the "Duracell Mobile Charger"/CEF23 in these forums as well as it is generally more available due to it's lower cost of manufacture than the CEF21. It charges at 500 mA for both formulations (0.25C for AA and 1/1.6 C for AAA). It also has 4 indpendent channels.

The CEF23 charges at about 40% higher current (550mA versus 400mA) than the CEF21. While most of the forum users refer to it as a "cool" charger, one user has termed it hot: The termination was fairly predictable based upon black_top Duracell LSD (Durabrid).

 

[Mr Happy]

While things generally improved, the type of battery was also just as or more important ...

Note that the Rayovac Hybrid that became a "hot potato" at 68°C was being charged at the 1C rate. Yet some will say without qualification that 1C is the recommended charge rate for NiMH cells. This recommendation does have to be tempered with the knowledge that 1C is too fast for some cells, and that if your cells get too hot you may be forced to use a lower charge rate.

 

[SilverFox]

Hello Mr Happy,

Let me see if I have this information correct...

Your RayOVac cells heated up to 68 C when they were charged at 1000 mA on the GP charger.

When you measured the capacity of those cells, they came in at 550 mAh, which is about 69% of their original labeled capacity.

Charging a 550 mAh cell at 1000 mA is about a 1.8C rate.

I believe I could correctly conclude that crap cells charged at high rates generate heat...

I believe there as always been the understanding that 1C charging gives a strong -dV end of charge signal for healthy cells. When cells are in the transition or have made the transition from healthy to crap, the standard 1C charging recommendation no longer holds true.

Now, with all of that said, I agree with your general conclusion...

Tom

 

[Mr Happy]

Hello Mr Happy,

Let me see if I have this information correct...

Your RayOVac cells heated up to 68 C when they were charged at 1000 mA on the GP charger.

When you measured the capacity of those cells, they came in at 550 mAh, which is about 69% of their original labeled capacity.

Charging a 550 mAh cell at 1000 mA is about a 1.8C rate.

I believe I could correctly conclude that crap cells charged at high rates generate heat...

You are right, it was 1000 mA. I was thinking 800 mA.

Although the cells tested at 550 mAh on the C9000 I think this is an inaccurate measure. It seems the voltage drop on the 1000 mA pulsed discharge that the C9000 uses causes the cells to reach 0.9 V prematurely. After the discharge ends the voltage rebounds to 1.24 V or greater, indicating the cells were not fully discharged.

Even so, I have to agree with you that those cells were charged at a higher than recommended rate. I will likely avoid using that charger on AAA cells in future.

 

[SilverFox]

Hello Mr Happy,

Keep in mind that sometimes cells respond favorably to a "healthy" charge rate, provided they survive the elevated temperature.

Tom