What's the Best Battery Charger?

I think this has been discussed before, but I couldn't find the thread(s).

I have a nagging sense that the latest batch of NiMH batteries I bought are wearing out more rapidly than they should. I recall reading that a slow, "trickle" charger is better both in terms of bringing a battery to it's full potential as well as prolonging the useful life of the battery. Apparently the charger which comes in the blister pack with many batteries may not be the one to meet the above.

What's the current thinking on the "best battery charger", and what do they cost? And is this charger a cost-effective option (i.e., does the increased cost offset the more frequent replacement of batteries)?

Thanks -

I can't answer your question about battery chargers, which I assume refers to chargers for the ubiquitous AA cells.

Gave up on rechargeables long ago, having decided they were unreliable (or inadequately reliable for my needs and purposes). My needs primarily have involved running photo flash units and (once upon a time) camera motor drive units.

Now I generally buy 20-packs of AA alkaline cells from the local "dollar" store (their house brand), at 25 cents a battery, mostly to run the flash units. They have proved themselves to be just as good (for my purposes) as much more expensive "premium" brand name batteries.

When I need longer-lasting AA batts or batts that will perform more reliably in cold conditions, I take a deep breath and go for Lithium cells. These come at much, much greater cost, but they really deliver the performance I am looking for.

My big concern about using any batteries is making sure they are disposed of properly when defunct. They cannot responsibly go in the ordinary household trash. Luckily, my local recycling agency will take them and do the job right.

Sorry for wandering OT ... (cabin fever victim).

G.

Kevin Rooney said:

I think this has been discussed before, but I couldn't find the thread(s).

I have a nagging sense that the latest batch of NiMH batteries I bought are wearing out more rapidly than they should. I recall reading that a slow, "trickle" charger is better both in terms of bringing a battery to it's full potential as well as prolonging the useful life of the battery. Apparently the charger which comes in the blister pack with many batteries may not be the one to meet the above.

What's the current thinking on the "best battery charger", and what do they cost? And is this charger a cost-effective option (i.e., does the increased cost offset the more frequent replacement of batteries)?

Thanks -

Click to expand...

Kevin,

I ran into the same situation. My batteries were Duracell AA 2650 mAh rechargeables. My charger is one of the “slow” models.

After a full charging they would lose the charge over the period of a couple weeks. My older versions of the same battery would hold a strong charge for nearly a year. I contacted Duracell and was told to try forcing a second charge cycle during the initial conditioning period. In other words, after the charger indicator goes green, unplug the unit and then restart another charge cycle on the same batteries. Evidently, they have been experiencing a false charge condition. They explained this will help force a full-capacity charge.

In addition, they sent me coupons to get free replacements - but would not admit to a problem with their product (good support staff training). They also recommended I use the pre-charged product. Unfortunately, the pre-charged model is a lower mAh rating and can’t be mixed with the older ones that I have. I’ll continue to use the 2650 mAh product.

Good luck!

Grumpy - Yes, I was mostly referring to the AA batteries, and to a lessor extent, AAA's. I don't use many triple AAA's, as they mostly go in my headlamp, and with LED's ... I only need to recharge them once or twice a year.

I understand the battery draw with flash units. I recently bought a Canon camera which uses AA batteries, thinking I wanted to get away from propriety batteries. I'm rethinking that -

BigEarl - that's interesting - will keep your Duracell experience in mind. For years I was very satisfied with the Kodak brand of NiMH batteries with a 1600mAH rating. When they started to wane, I stayed with Kodak, this time the standard seemed to be 2400mAH (the Walmart flavor, anyway). Over time, my battery draw has increased slightly - rather than a B&W Garmin Vista, I now have a color 60CSx, and I suspect the Canon camera is the biggest draw. So, maybe it's not the batteries nor charger, but simply my needs have grown at a slightly faster rate than the batteries capacity.

On another note - a couple of years ago I got a great deal on solar-powered outdoor lights, and when they failed a year later I understand why Home Depot was dumping them - their NiMH battery was of poor quality, and only put out 600mAH IIRC. Over the course of about a week, all of them (some 20+) gradually failed to fire up at dusk. I replaced those batteries with aging Kodak NiMH rated at 1600mAH and have had no problems for many months now.

The current crop of low discharge NiMH batteries will hold 90% of their charge for a year. That's definitely the way to go today. They don't have as high a mAH rating but they last longer in all typical uses.

This would be my choice for a charger today: http://www.mahaenergy.com/store/viewItem.asp?idProduct=178

I have an older Maha charger and it works great.

I use the MH-C204W, mainly because it has an integrated 100-240V 50/60Hz international power supply, usable anywhere in the world. Use it with their low discharge batteries.

Seems like the Maha series may be a good choice. Selecting the long charge cycle isn't a problem as I usually leave them in the charger overnight.

I did a quick search on Amazon, and found a Maha unit w/ 4 battteries currently listed at $40.75. Definitely on my public Wish List.

Whatever you do, do not use one of a high-current quick chargers on the type of NiMH cells that are low-leakage and keep their charge longer. These type of cells need a lower charging rate or else they will get damaged.

Slow charging any kind of cell is gentler to the cell. Heat and pressure are lower with slow charging, and the various seals last longer.

I have been advised by Maha and Maxxon that keeping a Nimh cell on trickle charge for a long time (ie leaving them in a smart charger perpertually) is not good for the cell. Maybe Doug Paul has some numbers.

Finally, before choosing a charger, decide whether you need to charge an even number of batteries or odd number of batteries. Some chargers only charge pairs, and there are plenty of devices out there that use 3 cells.

Maha makes charges that meet all of the above concerns. I have a C401S.
It charges 1,2,3 or 4 cells. There is switch on the side to choose low or high charging rate, so it can work with the low-leakage cells or higher-capacity cells.

Also, the C401S comes with a cigarette lighter adapter so u can take it on the road with you.

By high-current, quick chargers I mean those that can charge a cell in 15 minutes. The Sanyo Eneloop low-leakage AA cells can be charged at 2000mA according to a Sanyo Data sheet.

However AAA Sanyo Eneloops can only be charged at 750 mA.

Have a look at the La Crosse BC-700 or BC-900:
http://www.amazon.com/Crosse-Techno...rger/dp/B000RSOV50/ref=acc_glance_k_ai_-2_t_1
In addition to selectable charge rates, these chargers have separate modes for conditioning and testing actual battery capacity, which is very useful for weeding out cells that you suspect may not be holding a charge. It also lets you verify the actual capacity vs. the advertised number. Definitely go with LSD batteries, unless you absolutely need the maximum possible capacity. These are sometimes sold as "precharged", which is only feasible because they hold their charge so well. The Sanyo eneloop is a popular brand, but there are many others.

Kevin Rooney said:

What's the current thinking on the "best battery charger",

Click to expand...

DC...definitely DC.

Kevin Rooney said:

...What's the current thinking on the "best battery charger"...?

Click to expand...

Any good District Attorney.

I have been using a Maha C777Plus for 15? years. It will charge NiCd, NiMH, and Lithium rechargeable. Its not cheap but it not only charges but it reconditions and tests. I find it to be a really good charger.

Keith

Billy said:

Any good District Attorney.

Click to expand...

Nah, the best would be Sgt. Alvin York.

Thanks to all who have pointed the way toward the Maha line. Good info to have.

I have several chargers, including the Maha MH-C401fs and the MH-C204. Both are good chargers, but I prefer the 401 because it has four independent charging circuits and the 204 has only two. (It can only charge batteries in matched pairs and batteries become mismatched over time. Or your headlamp uses three... Independent circuits are better because the charge is tailored for each battery individually.)

I also have a Lacrosse BC-900 (the Maha MH-C9000 is similar). It is similar to the C401 with the additional capability of measuring the capacity of the cells. This can be useful after you have had some batteries for a while and wish to evaluate and sort out those that are getting weak. (I also label all my batteries so I can use them in matched groups and keep track of their health.)

The MH-C401fs is a good basic charger. A good "starter' charger (and probably the one that I use most often).

"Standard" AA cells have a capacity ~2600 mAh (AAA ~900 mAh) and low-discharge AA cells have a capacity ~2000 mAh (AAA ~800 mAh). I have some of each kind, but will probably be standardizing on the low-discharge cells in the future. (Standard cells will discharge significantly faster while sitting on the shelf than low-discharge cells. However, if you top off the charge shortly before using them, the standard cells work fine.)

FWIW, I use Sanyo Eneloops for my low-discharge. They pretty much set the standard...

Trickle charging is not a good way to charge or store NiMH cells. They charge best at a several hour charge rate using a "smart" charger. (A non-smart charger is likely to damage the cells.) Things that damage NiMH cells: overcharging, overheating when charging (typically by charging too fast), discharging to zero or reverse charging (by trying to get the last bit of use out of them). It is good to charge them frequently (there is no need to discharge them fully)--if charged properly using a good smart charger, they do not develop a memory effect. (Memory effect is primarily seen in NiCad cells.)

Many of the chargers run on 12 volts and come with (or offer) a 12V automotive cord. Many also come with (or offer) international power supplies (120-240 V, 50-60 Hz).

NiMH batteries are much better than alkaline batteries in digital cameras. Digital cameras tend to draw high currents for short periods of time--NiMH is good at this, alkaline is poor at best. (NiCads, lithium non-rechargeables, and Lion (lithium ion) rechargeables also work well in this kind of service.)

I use NiMH batteries in my camera (at least the one that will take AA cells...), headlamps, GPS, bike lights, radios, etc. (Alkalines are better for smoke and CO2 detectors, clocks, and other indoor low-drain applications.)

A good place to buy NiMH batteries and chargers:
http://www.thomasdistributing.com

Professional quality info on NiMH batteries:
http://www.batteryuniversity.com/index.htm
http://data.energizer.com/

This general topic has been addressed a number of times in the past: just search on NiMH and lots of relevant threads will appear.

Standard caveat: I have no connection with any of the companies mentioned above. Just a user or customer.

Doug

Kevin Rooney said:

On another note - a couple of years ago I got a great deal on solar-powered outdoor lights, and when they failed a year later I understand why Home Depot was dumping them - their NiMH battery was of poor quality, and only put out 600mAH IIRC. Over the course of about a week, all of them (some 20+) gradually failed to fire up at dusk. I replaced those batteries with aging Kodak NiMH rated at 1600mAH and have had no problems for many months now.

Click to expand...

Actually, NiCads work better in this kind of service--low drain (often to exhaustion) with trickle charging and widely varying temperatures (ie frequent abuse). NiCads are a lot more rugged than NiMHs, but the cadmium makes them hazardous waste. (Don't throw out NiCads--recycle them. Radio Shack and lots of hardware stores will take them for proper disposal.)

Doug

Lots of good info (and a bit of humor )- thanks to all for creating this resource.

Oops. I should point out that the MH777 doesn't actually charge AA and AAA batteries directly. It is made mostly for power packs but I have been using AA and AAA battery packs that can be attached with alligator clips that come with the charger for so long I forgot that. So, it can be done with a 4 or 8 battery case from radio shack but doesn't actually come with it. It is an amazingly versatile charger.


Sorry for any confusion on that,
Keith

SAR-EMT40 said:

Oops. I should point out that the MH777 doesn't actually charge AA and AAA batteries directly. It is made mostly for power packs but I have been using AA and AAA battery packs that can be attached with alligator clips that come with the charger for so long I forgot that. So, it can be done with a 4 or 8 battery case from radio shack but doesn't actually come with it. It is an amazingly versatile charger.

Click to expand...

The MH-C777 looks fine for battery packs, but looks like it can charge only one item at a time. The ability to charge cells individually is desirable, so if you have a bunch of AA or AAA cells you are probably better off with a charger that simultaneously charges several cells individually (eg MH-C401 or MH-C801).

I have several "lost" battery packs where one cell appears to be weak, but since the pack is sealed the entire pack must be replaced. If I could get at the cells individually, I might be able to fix (rejuvenate) or replace the weak cell... High quality battery packs (eg laptop batteries) often have external connections to each cell and internal temperature sensors to allow one to maximize the useful lifetime.

Doug