NiMH 15 Minute Charger Question

The 15 minute charge is to about 85% according to measurements. Getting the last 15% needs a slower charge. This is inherent in how NiMH cells work and not much can be done about it in the charger.

Ultra-fast charging is probably harder on the cells. Also, the 15 min charger has a cooling fan which means the charger makes noise and is vulnerable to dust getting sucked in, etc.

An 8-11 hour charger is probably not a great choice since they tend to be timer controlled and therefore can't tell when your cells are fully charged. My favorite AA charger is the LaCrosse BC-900 which has an LCD display that shows the cells' measured capacity etc. For your

I agree with the comments on a few hours' charger. One thing to keep in mind is that if you travel, a charger that takes 120-240V input is a good idea.

The 15 minute value is for the batteries specified in the device literature. Batteries with larger capacities will take a bit longer to charge. Those with less capacity, a bit less time. As for whether this is good for the batteries, it can't be, but then they don't cost a lot anyway so if it reduces the use life by 75%, some people would still consider it a good deal for the time savings.

Best chargers are those that limit the temperature, and monitor charge rate of each battery, and reduce the charge rate to a trickle when the battery is about 90% charged. They will take from 1 to 3 hours to recharge a battery, depending on the charge state when they begin charging.

to

Note that to charge a 2300mAH cell in 30 mins the charger must supply 4.6A per cell roughly.

Hi...

Not nearly enough... about 6.5 amps.

Ken

As for the Energizer charger, unknown right now if they use the regular charging method or the Rayovac pressure cell trigger (unique vs. other regular charge methods - the stop of cycle is triggered by the cell, not by external monitors on heat, etc). All chargers will partially charge cells if not kept in there the entire required charge time.

"The new and improved high capacity, longer lasting AA NiMH battery is 2500 mAh. What does this mean?

NiMH batteries have varying mAh or milliamps ratings. These ratings indicate the power capacity of the battery. The higher the capacity, the longer the battery will last between charges. AA 2500mAh batteries will be charged in approx. 20 min. in the 15 Minute Charger, 1 hour in the 1 Hour Charger, 5 hours 30 minutes in the Universal Charger, and 12 hours in the Compact Charger. Lower mAh will be charged in less time."

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Here, the older 2300mA Energizer tested to be the best of the range of cells out there, so the 2500mA should be better (ie. longest lasting):

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NiMh have very good charge acceptance at high rates so just over

=>considering buying this one by energizer: =>

=>One question that i cant find the answer to is: will this charger be able to =>charge these batteries to their full =>capacity just in a shorter period of time, or if it will charge them but =>only partially in the first 15 minutes. =>Is this charger just as good as the others but just have some advanced =>technology to charge faster or is there =>a tradeoff to its ability to charge quickly? =>

=>So would you recommend i get one of the 8-11 hour chargers or is this one =>will be able to charge my batteries =>to their full capacity. =>

=>Thank You =>

Thanks for the "heads up" on this new product. LaCrosse is a company that sells radio-controlled watches, weather vanes, and the like ... not the sort of house you'd expect to be marketing a leading-edge battery charger! But, yet it is. From the styling it clearly looks European (German ... like Accupower or Ansmann) in design.

After drooling over the specs I quickly ordered one from Thomas Distributing and have been playing with it for a couple of days now. What an amazing "thinking person's" product. Too bad it uses a weird power supply spec (3VDC at 4A) or it'd be nice to run it in the car too.

Seemed to be "obsolete proof" too ... until I noticed that the firmware is only set up to keep track of cells of 3000 mAH capacity and lower. I don't suppose that advances in NiMH chemistry will result in 3100 mAH penlite cells any time soon ...??

The unit displays a firmware rev on power-up, but the manual makes no mention about upgradeability. Maybe time to take a look inside to see if there is a data connector or pads.

Ansmann learned their lesson, I think. My version of the Powerline-4 has a brick wall timer limit (the HP Marketing rep that visits here every now and then hedged back and forth but finally admitted it). This makes it impossible to fully charge cells much over 2100 mAH in one run. They fixed that on later designs - but that didn't help me, of course.

I'm not so sure. Everything is controlled by the microprocessor, even a "straight" charge run. It keeps track of (and displays) the amount of energy delivered to each individual cell ... so if there is some high limit to the charge capacity it might be reached on higher capacity cells, too.

I'll put that on my "to do" list. At this point I'm still getting familiar on how it handles old, new, and "damaged" cells of much lower capacity than 3000 mAH.

If you're into this sort of thing, I think it's still worth investigating.

Yeah, the Energizer 15 minute charger can run on 12 volts and I figure it's better than the LaCrosse for use in the car, since it's so much faster. You don't need to be on a long trip to get enough charge time.

I dunno. NiMH capacity increases may be slowing down? I'm using Sanyo 2500 mAH cells now, and most of of mine measure slightly below

LaCrosse is a company that

FWIW, they absolutely support their products. They sent me a new weather sensor to replace one that hit concrete hard as a result of a failed mount. No arguments.

My 3 year old Ansmann Powerline Traveller right now is charging Ansmann and PRO 2500 cells. Your will also.

My Energy 16 also does these cells with no problems. I fully expect both chargers to handle the 2600 Ansmann cells as well when they are available.

Nope. It has a 3-hour cutoff timer. At 700 mA charge rate ... you can do the math :-(

I should have mentioned that I had experience with this company prior to getting the BC-900 charger. I have a discontinued-model radio-controlled watch that would not set itself automatically quite some time after the warranty had expired. They simply sent me a new one.

The advantages of modern technology. Electronics progress but the printing in the instructions and on the back of chargers don't change as fast.

The Ansmann Powerline 4, 6 and the Energy 16 and 8 all charge 2500 mAh. Of course they don't do it as fast as the latest Ansmann DigiPower Ultra which outputs 4.3A for AA cells.

What is the voltage/current output of the AC/DC adapter that comes with the BC-900?

I'm wondering why it doesn't have an option for in-vehicle charging. I know that on one Ansmann charger, they are concerned about the heat that is exhausted, so they don't offer a car cord option, even though it would work other than the danger of setting your car on fire!

Steve

You could use a 12vdc to 120 vac inverter.

I wonder if there's an issue like that for the Energizer 15 min charger, which does run on 12 volts but for some reason doesn't include or offer a car cord. I'd feel ok using it in a car as long as it wasn't buried under anything and its fan could get plenty of air.