The elusive smart charger for Sanyo Eneloop AA/AAA batts

[dc38]

Re: Questions about Eneloops and chargers for them

Starting the charge now. One battery is near depleted at .88V, the other is near full at 1.22V, so we shall see...

 

[zenbeam]

Re: Questions about Eneloops and chargers for them

Starting the charge now. One battery is near depleted at .88V, the other is near full at 1.22V, so we shall see...

I appreciate your risking life and limb for the cause! :naughty:

 

[Wrend]

Re: Questions about Eneloops and chargers for them

The problem is that you'll overcharge the full cell or the lower cell won't fully charge. (It depends how your specific charger terminates the charge.) Then when you go to use the cells the lower charged cell runs the risk of being damaged by being driven into reverse by the still full cell.

You can charge cells in series at a slow charge rate (0.1C/h or less - about 200mA for Eneloop AAs), and it won't significantly damage the overcharged cells. The lower the rate, the better. Still not great for them though.

Eneloops are pretty hearty, so they can put up with a bit of abuse better than some cells. But why not get the most out of your investment? You can find more basic (less expensive) independent port chargers.

 

[dc38]

Re: Questions about Eneloops and chargers for them

Wrend, You are absolutely right. It SEEMED (unscientifically of course) that the charge of one cell was subsidizing the other cell in my experience. One of the cells (the higher charge) came off the charger at 1.52 volts, the other at a health 1.42. I have a bad feeling that if I had continued charging them for any longer, the cells would be permanently and irreversibly damaged :/. So from this one trial, I'll just say to refrain from charging two unbalanced cells just in case...(Since I don't have many multi celled lights, 2 xenos, I just completely deplete each cell until I can charge two at once. Problem solved!

 

[Magic Matt]

Re: Questions about Eneloops and chargers for them

That's a convincing testimonial. I feel like I'll have to become educated on cell charging. I don't really know much about it.

I don't really know that much about it either - I can see why this charger is also called a Wizard!

I've just done what others have told me to with it - ie do a quick cycle on new batteries to break them in before use, and the results have been that even the cheaper cells have worked much better. I've generally bought Eneloops, but before I knew there was such a difference I used to buy pretty much any old thing. This charger can analyse the batteries and tells me what capacity they actually deliver, rather than what's on the label, and in some cases it's very surprising! I don't fully understand why, but I've also been told to match batteries of similar capacities together, and it works out better when I do. I've also stopped dumping perfectly functional cells by identifying one single bad cell in a set of 4, whereas before I would have assumed they were all destined for the recycling box. Also as I sit here, I have some cells from a wildlife charity that they use in their wildlife cameras that have been performing badly, and just be running the refresh cycle, then break in, then refresh again individual cells have improved between 30% and 70% - that's around 60 AA cells they now wont need to replace (all were destined to be recycled, only 7 out of the set have so far been condemned as knackered).

I think what has impressed me most is that it's made a difference to my cells, but without me having to become a cell nerd, if that makes sense. I've learnt more about charging cells because of the results I've got from charger, rather than having to learn about cells first.

I'm sure there are probably other chargers out there that do the same things, but I wouldn't swap this one for anything, I couldn't be more pleased with it.

 

[tickled]

Re: Questions about Eneloops and chargers for them

I have a C9000 and MQH03 (bundled Sanyo 2 hour charger with 4 independent channels) and both seem to perform well. I would not consider it a handicap if I only had the latter.

 

[zenbeam]

Re: Questions about Eneloops and chargers for them

I'll just say to refrain from charging two unbalanced cells just in case...(Since I don't have many multi celled lights, 2 xenos, I just completely deplete each cell until I can charge two at once. Problem solved!

dc38 - I'm glad you didn't fry your charger, batteries or home in search of truth! Excellent advice on the discharge idea. I had pondered that already. I have a 2xAA light, so that one is easy to handle, but the rest of my AA and AAA lights are single battery lights. So when one finally does deplete, it makes perfect sense to just discharge another fully - then charge them together.

Besides, running a light until discharge is yet another opportunity to get some use out of it and fiddle with ceiling bounce or going to the restroom without turning on the "real lights", etc.... lol. Okay.. I did just really say that. :wave:

 

[Trevtrain]

Re: Questions about Eneloops and chargers for them

I have a C9000 and MQH03 (bundled Sanyo 2 hour charger with 4 independent channels) and both seem to perform well. I would not consider it a handicap if I only had the latter.

Well, each to their own of course tickled. :wave:

I've no doubt the MQH03 does the job but if you ever use your cells in series (a 2 x AA gps or 3 x AAA light for instance) your C9000 helps you to better select cells of matched capacity.

It is easy to send at least one cell into reverse polarity in a series setup, especially if you or someone else in your family tends to run flashlights until they are completely dim. In this case it is almost certain that at least one of the cells has been subjected to reversal, which is very, very bad for its long-term prospects. :shakehead

The ability of the C9000 to test a cell for its actual capacity rather than the stated nominal rating means its possible to match cells evenly for a series use device. I have a couple of Sanyo USB chargers MDU01 (independent charging for each cell, delta V cutoff) that get regular use, but I still like to check each cell in the C9000 periodically to record its actual capacity. I like my USB chargers, but I personally would feel handicapped without the C9000.

I guess for anyone who only ever uses single-cell devices it wouldn't matter.

Just my 2c.

 

[Trevtrain]

Re: Questions about Eneloops and chargers for them

dc38 Besides, running a light until discharge is yet another opportunity to get some use out of it and fiddle with ceiling bounce or going to the restroom without turning on the "real lights", etc.... lol. Okay.. I did just really say that. :wave:

Yes zenbeam, I'm afraid you did just really say that - and in doing so, proved that you are indeed truly worthy of your "Flashaholic" status. :thumbsup:

 

[dc38]

Re: Questions about Eneloops and chargers for them

hahaha...my sentiments exactly

 

[Al Thumbs]

Re: Questions about Eneloops and chargers for them

Thanks to all who answered. I learned a lot! I have ordered the Maha C9000 and some AA & AAA Eneloops from Thomas Distributing, will be looking for info on using that charger next week.

What's the deal with new Eneloops? Use 'em until they are discharged, or do the Break In cycle right away?

Al T.

Forgot to say- every time I read "Maha" in a post, a part of my mind answers, "Ah-ha?"

 

[Trevtrain]

Re: Questions about Eneloops and chargers for them

I'm sure you won't regret it Al Thumbs. :thumbsup:

There should be an instruction sheet for your C9000 in the box. It gives you pretty much all you need to know. In the meantime you can type "Maha C9000 manual" into Google and get a PDF for a little light reading in advance if you like.

There are also plenty of threads in here by some very knowledgeable people who like to discuss the C9000 and all things battery related. I think I have read most of them at one time or other. Any of the posts by member "Silverfox" are well worth a read. (No offence intended to other equally well qualified contributors.)

Just watch the dates on the threads when you search though - there have apparently been few firmware revisions on this charger since it was released. The problems some members here have mentioned are likely only in the older versions. I've had my Maha for about 12 months and haven't experienced any of the issues that came up years ago.

As to breaking in the Eneloops. There appear to be any number of answers to that question. The Eneloop marketing department would say "just use 'em." I always do a refresh & analyse on mine. Some would say do a Break-In. Remember that the full Break-In cycle can take up to 40 hours to complete. That's a long time to wait when you have new toys to play with. :naughty:

Thanks to all who answered. I learned a lot! I have ordered the Maha C9000 and some AA & AAA Eneloops from Thomas Distributing, will be looking for info on using that charger next week.

 

[Wrend]

Re: Questions about Eneloops and chargers for them

Yeah, it's fine if you just want to use them and then charge them up normally, or charge them first before you use them. Just be sure to not use freshly charged cells with new ones since the new ones are only charged to about 75% capacity.

I personally make series sets of cells that only get used together, so I discharge all my cells first on the C9000, then do the break in on them to test them and match them up by their capacities. That's a bit much for the average user though.

 

[Al Thumbs]

Re: Questions about Eneloops and chargers for them

I personally make series sets of cells that only get used together, so I discharge all my cells first on the C9000, then do the break in on them to test them and match them up by their capacities. That's a bit much for the average user though.

What is an easy-to-grasp definition of capacity? Is it different from cell to cell among Eneloops, rated at 2000maH? Does a cell's capacity change over the course of its life? How do you make sets, do you label and number? I guess one can get deeply into this!

Al T.

 

[SilverFox]

Re: Questions about Eneloops and chargers for them

Hello Al,

Welcome to CPF.

Capacity is the cells ability to deliver a current over a period of time. In a perfect world a cell that had 2000 mAh of capacity and connected to a load of 500 ma would last 4 hours. Unfortunately, the world is not perfect and you actually get a little less than that.

Matching cells is done when you have multi cell applications. You don't want one cell to run out of capacity before the other, so matching on capacity gives you protection against that.

One way to match is to do a Break-In and compare the capacities reported at the end of that process. Another way to match is to figure out what load will be put on the cells, and use that as your discharge rate. Due to heat losses cell capacity will be reduced a little at higher currents.

When you finish your testing and have recorded all the capacities, you can then sort the cells according to their capacity. The closer they are in capacity, the better they will work in a multi cell application.

:devil: I am sorry to inform you that you have been misinformed... You can never get too deep into batteries and charging.

Tom

 

[Woodsroad]

Re: Questions about Eneloops and chargers for them

Greetings, Stored Energy Lovers,

FWIW, back in 2010, I read through the CandlePowerForum front-to-back before buying NiMH AA's. I'm a pro photographer and use AA's in all manner of gear, both high discharge, like strobes, to low-discharge, like radio slave units. Basically, the suggestions on the forum back then were the same as today: Eneloops have the best life expectancy and the best manufacturing QC. Other off-brand batteries are pretty much untested and unknown.

Good advice.

Charger advice was more varied, but folks seemed to like the LaCrosse charger (except for that one batch that tended to catch fire!) and it offered the best flexibility in terms of setting charge/discharge rates in an easy to read manner. On charging, there was all manner of advice: 1c is ok, .5c is best, yadda yadda yadda. I use a lot of SLA rechargables, though, and applied that knowledge to recharging NiMH's:
The lower the charge current, the longer the batteries will last.

So, as an experiment I ordered Eneloops, Powerizer 2600, Tenergy 2300 batteries and a LaCrosse 9009 charger. Batteries were cycled when new @ 200mah charge and 100mah discharge. Yes, it took a long time to cycle them all! The Eneloops were all at or above rated capacity. The Powerizer and Tenergy were all below rated capacity, mostly in the 2.0ah range. I marked a sample of 8 of each battery brand with the date and ah rating. The batteries went out into my gear bags and went to work. Most were well taken care of, but some were left on in strobes and discharged down pretty low. All batteries were promptly recharged on the LaCrosse charger at 200mah.

I also gave a set of Eneloops and an Eneloop 4-slot charger to my 10-year old daughter to use in her point-and-shoot camera.

Two years later, I have no dead batteries. I rechecked capacity ratings, and all had fallen an average of .15ah. None lower than .3 ah. Wow. That's not much, is it? The cheaper batteries have performed exactly as well as the Eneloops.

My daughter, who was not quite as careful with her batteries, ended up with four dead batteries after two years. Not a well-controlled experiment, but there's an anecdotal data point for you.

So, anyway, in my test once I got past the fact that the Powerizer and Tenergy batteries are 2ah, ~not~ 2.3 or 2.6, I was still left with the fact they performed exactly like the eneloops at, what? half the price?

A fresh order of Powerizer 2600, Tenergy and Eneloop 1500's arrived over the past week. I also bought two more Lacrosse BC700 chargers (bringing the LaCrosse total to 4) and a Tenergy TN160 for bulk charging (anyone know what the charge rate is on that unit?). The new batteries are getting cycled, rated and marked now. Right now, the Powerizers are all looking like they are 2.4 to 2.6ah capacity, so they are not the same batteries as they were two years ago. The sample size will be larger this time, 16 batteries of each type. They will go in to service alongside the existing stock of batteries.

I'll report back in two years.

If I was more obsessive-compulsive and had less work, I'd have colorful graphs and exact recharge cycle data for you. Oh well.

That is all.

 

[Al Thumbs]

Re: Questions about Eneloops and chargers for them

Capacity is the cells ability to deliver a current over a period of time. In a perfect world a cell that had 2000 mAh of capacity and connected to a load of 500 ma would last 4 hours. Unfortunately, the world is not perfect and you actually get a little less than that.

Is a 2000mAh cell rated as 2000mAh per hour?

One way to match is to do a Break-In and compare the capacities reported at the end of that process. Another way to match is to figure out what load will be put on the cells, and use that as your discharge rate.

Is the load stated somewhere? Do you have to calculate or measure it?

When you finish your testing and have recorded all the capacities, you can then sort the cells according to their capacity. The closer they are in capacity, the better they will work in a multi cell application.

How do you manage your cells? Labels? Notes?

:devil: I am sorry to inform you that you have been misinformed... You can never get too deep into batteries and charging.

I do fear it much! Thanks for the info, Tom.

Al T.

 

[Magic Matt]

Re: Questions about Eneloops and chargers for them

The label on cells can vary, but you'll see two figures. One is voltage, one is capacity.
Eg 1.2V 2000mAh

The load is how much power you are drawing from the cell, so that depends on what you're using it for. A toy car for example may draw far more from a cell than an average flashlight (on these forums that may well be the other way around). The consequence is the more the load, the more you draw from the battery over a period of time, so the less time the battery will last. More load, shorter run time.

I manage my cells by writing on them with a CD pen. I give them a reference number, and then I have a spreadsheet that I keep a note of their capacity at any given time (when I remember to check it).
Eg.
Cell 13 - AA Eneloop - purchased Jan 2011
Jan 2011 - Capacity 2048mAh
Mar 2011 - Capacity 2012mAh
Jun 2011 - Capacity 2018mAh
Aug 2011 - Capacity 1990mAh

Every now and then I might do a capacity check on a batch, then match them up in the little containers they come with according to capacity. In one container here on the desk I have cells 12, 18, 22 and 23. All are Eneloops, and all around 2030mAh when tested.


I don't do this obsessively, I do it as and when I remember, or if I have something happening where I anticipate needing them, such as a holiday (where I'll want them in flashlights, camera flashes, CD player etc.)

 

[Woodsroad]

Re: Questions about Eneloops and chargers for them

I don't do this obsessively, I do it as and when I remember, or if I have something happening where I anticipate needing them, such as a holiday (where I'll want them in flashlights, camera flashes, CD player etc.)

Don't fret, Matt, we know that you are not obsessive.

Just having a really good battery charger and posting about it online doesn't make someone obsessive. Having a really good battery charger AND a label-maker AND posting about it online makes someone obsessive.

And if you also get itchy teeth, and your fingers curl up a little when you think about buying even more batteries and testing them, then that makes you obsessive-compulsive.

Otherwise, you are OK. :thumbsup:

 

[tickled]

Re: Questions about Eneloops and chargers for them

The Powerizer and Tenergy cells would not be low self discharge chemistry?