Will battery matching fix poor performance?

[fireguy]

Hello, again!

I've been doing quite a bit of reading on this CPF and I'm learning a lot. Thanks for the great wealth of information on here!

I've used NiCd batteries since the early 80s but never found they had the power of alakalines. Switching to NiMh a few years ago, it seemed better, but it just wasn't quite there. Recently I found my Canon digital camera was suffering poor performance. The low battery icon would flash much sooner than I thought it should. I thought that perhaps the camera was defective. When I would take the batteries out and place them in the charger, 3 of them would typically show an almost full charge while one would be nearly dead. This didn't seem to make sense until I've read about battery matching on here. I'm thinking that this is my problem, and that using the C9000 to analyze the batteries will help. I'm going to match the batteries with similar capacities, but how close do they have to be? And I'm also thinking that the labelled capacity becomes meaningless in this case. A 2700 mAh battery showing a capacity from the charger of 1,000 mAh would match a 1200 mAh battery showing a capacity of 1,000 mAh? Of course this is just an example, and a 2700 mAh battery with a capacity of 1,000 mAh would need to be replaced.

Am I on the right track, oh wise contributors of CPH?

I don't know why, but I find this really funny: :poke:

 

[Mr Happy]

Do you own a C9000 already, or are you thinking of buying one? If you do not own a C9000, what charger do you currently have?

It may be that if your existing charger is satisfactory, then your cheapest and most effective solution might be to buy a set or two of Eneloops for use in the camera.

It all depends how much you use rechargeable batteries in different things, and how involved you want to get with battery maintenance.

 

[Marduke]

Try running a refresh cycle to see if they perk up.

 

[fireguy]

Do you own a C9000 already, or are you thinking of buying one? If you do not own a C9000, what charger do you currently have?

I just received my C9000 a couple of days ago. It's a great piece of equipment! I also bought some Eneloops this morning from Costco but haven't had an opportunity to try them out yet. I presume that they can benefit from the C9000's break-in (forming) charge? Would you recommend that I do this with the Eneloops?

I did have (and will also continue to use) the SCH-600F USB charger. It has 4 separate channels and an LCD showing the battery level (in 3 slices). It seems to work very well.

After I do the refresh cycle, Marduke, I assume that grouping the batteries together by reported capacity is still a good idea? I'm just wondering if my previous problem was caused by batteries of greatly differing capacities? If I understand it, the batteries in series work like the "weakest link", where the overall performance is limited by the lowest-rating battery?

Thanks for all your input. CPF is a great place filled with friendly, knowledgeable people! I had no idea how little I knew about batteries or chargers before I found CPF! :sick2:

 

[Marduke]

Yes, grouping will help maximize performance.

I recommend using Eneloops in your camera. They are better suited for voltage-sensitive devices, and are more likely to be ready to use when you need them.

 

[Mr Happy]

I just received my C9000 a couple of days ago. It's a great piece of equipment! I also bought some Eneloops this morning from Costco but haven't had an opportunity to try them out yet. I presume that they can benefit from the C9000's break-in (forming) charge? Would you recommend that I do this with the Eneloops?

You can do the break-in charge on the Eneloops and it will do no harm, but the indications we have are that Eneloops are pretty well conditioned at the factory and you can just go right ahead and start using them. In fact, it would be of interest to many of us if you tried them in the camera without even charging them first and see how many shots you get out of the package before they need charging.

When you do charge them, I find that the default 1 amp charge rate on the C9000 works fine.

 

[mdocod]

eneloops are the only NIMH AA cells that will even run my camera for more than a few shots, all other types I have tried cause the low-battery warning system to come on prematurely, and then the camera shuts down shortly thereafter.

It's a common problem, especially on 2xAA powered digicams.

 

[TakeTheActive]

...I'm just wondering if my previous problem was caused by batteries of greatly differing capacities? If I understand it, the batteries in series work like the "weakest link", where the overall performance is limited by the lowest-rating battery?

Yes.

If you compare the voltage of an alkaline to a NiMh during discharge, you'll see the alkaline continuously decrementing while the NiMh has a 'plateau' at ~1.1V, and then a 'steep cliff'. Picture an airplane with 4 engines (let's say the old propeller kind ;) ). The pilot will take off, climb to altitude and then settle into cruise - all engines balanced, rudder neutral, airplane travelling in a straight line. If one engine stops, for whatever reason, the airplane will turn due to uneven thrust.

So, now you have a camera with 4 AA cells. ~1.2V, or better, each for ~4.8V total to start out, eventually ~1.1V each or ~4.4V at the 'plateau' during the extended period of 'straight & level cruise'. When the "weakest link" gives out, very quickly you're heading towards 3.3V, camera shuts down, airplane begins a turn - no matter how strong the remaining cells, engines are.

...Recently I found my Canon digital camera was suffering poor performance. The low battery icon would flash much sooner than I thought it should. I thought that perhaps the camera was defective. When I would take the batteries out and place them in the charger, 3 of them would typically show an almost full charge while one would be nearly dead. This didn't seem to make sense until I've read about battery matching on here. I'm thinking that this is my problem, and that using the C9000 to analyze the batteries will help. I'm going to match the batteries with similar capacities, but how close do they have to be?

Well, in your camera example, where you're using it until it shuts down, as close as possible! :D When the "weakest link" gives out, the camera is kaput. In another application, let's say 8 AAs in a handheld aviation transceiver that never shuts down during the day and will get recharged (i.e. topped off) nightly, maybe not so close.

...And I'm also thinking that the labelled capacity becomes meaningless in this case. A 2700 mAh battery showing a capacity from the charger of 1,000 mAh would match a 1200 mAh battery showing a capacity of 1,000 mAh? Of course this is just an example, and a 2700 mAh battery with a capacity of 1,000 mAh would need to be replaced...

I've never tried that, but in theory, if a MH-C9000 reports both as 1000mAh, it's not reading that off the label. :)

Labelling your cells, tracking their capacities in a spreadsheet, properly maintaining them with a Charger/Analyzer like the MH-C9000 (or BC-900) and using matched cells in a device will return to you the best performance, economy and satisfaction.

 

[asdalton]

Using matched cells may help, but the real problem is that too many electronic devices are designed with voltage detection circuits that expect the higher open-circuit voltage that alkalines have. The irony is that NiMH cells can deliver more power in high-drain devices than alkalines--but a poorly designed low battery sensor will declare these batteries "dead" long before they actually are.

 

[fireguy]

Picture an airplane with 4 engines <snip>

What an excellent analogy! That hit the point home. Thank you, makes perfect sense now.

So, now you have a camera with 4 AA cells. ~1.2V, or better, each for ~4.8V total to start out, eventually ~1.1V each or ~4.4V at the 'plateau' during the extended period of 'straight & level cruise'. When the "weakest link" gives out, very quickly you're heading towards 3.3V, camera shuts down, airplane begins a turn - no matter how strong the remaining cells, engines are.

Yes, now that I see this, it makes sense.

Labelling your cells, tracking their capacities in a spreadsheet, properly maintaining them with a Charger/Analyzer like the MH-C9000 (or BC-900) and using matched cells in a device will return to you the best performance, economy and satisfaction.

Great idea! I decided to to a break-in run on all my NiMh's since they've all been abused to some extent. Some are quite a few years old, others are not. But tracking them and having a charger/analyzer that gives me an actual value showing their capacity will help. And all these years I thought batteries were just batteries. :duh2:

I am sensing a new addiction forming, however! :laughing:

Thanks for the input, everyone!

 

[TakeTheActive]

...Picture an airplane with 4 engines (let's say the old propeller kind ;) ). The pilot will take off, climb to altitude and then settle into cruise - all engines balanced, rudder neutral, airplane travelling in a straight line. If one engine stops, for whatever reason, the airplane will turn due to uneven thrust.

What an excellent analogy! That hit the point home. Thank you, makes perfect sense now.

BUT, if you lose *ALL* of your engines: Plane in the Water: How Flight 1549 Averted Tragedy

MAN! That pilot did a *GREAT* job!!! :twothumbs

 

[Hoggy]

Great idea! I decided to to a break-in run on all my NiMh's since they've all been abused to some extent. Some are quite a few years old, others are not. But tracking them and having a charger/analyzer that gives me an actual value showing their capacity will help. And all these years I thought batteries were just batteries. :duh2:

I am sensing a new addiction forming, however! :laughing:

I hear that!
A little while ago I was thinking to myself - "yeah - I'll never become anal enough to label batteries and record them in a spreadsheet."

Now here I sit - labeling batteries, doing break-ins, recording capacities in a spreadsheet, and pairing up the similar cells. :crackup: