Using a mouse for cheap/full battery discharge function

[PeAK]

Discharging NiMh batteries by powering your cordless mouse might be an ideal way to condition your batteries while not overdoing it. Here are some measurements/observations:

1. My particular mouse (Logitech) needs only be recharged about once a month (averages 2mA in powerdown mode). It draws at most about 100mA peak during operation and much less when the mouse is waiting for my input between movements.
2. When the the batteries are nearly depleted and before the mouse freezes and stops operating, the mouse can operate down to about 1.2V when generating signals during mouse movements. When these movements cease, the voltage recovers to about 2.2V

As the battery becomes depleted, the chemical reactions needed to sustain the voltage do not exist and the battery voltage drops under load (even moderate loads like the mouse). The battery appears to have a very high value of internal resistance.

I suspect that at the point that mouse ceases operation is a very good indication of the 'knee" of the battery discharge profile (i.e. being fully depleted).

So this might be a cheap way to perform 1/2 the refresh function for those that do not have a charger/analyzer with a discharge to 0.9V feature.

This might even be more optimal for NiCad batteries. To date I've only used batteries that have measured high "internal resistance" in my mouse. The discharge period is so long (30 days) that I've not been able to charge them up and see if they work in my digicam effectively.

What might be neat is to have some of the Maha 9000 owners discharge a pair of batteries to 0.9V and to pop those into their cordless mouse to discharge them more fully. Give them a regular charge and then see if the internal resistance decreases. Any takers ?

PeAK

 

[jhellwig]

It is my understanding that slow discharges and charges are partial causes of high internal resistance. I have read that very high rates of charge and discharge reverse high internal resistance slightly. I have tried this on some old batteries and they showed some improvement but not much.

 

[Hoggy]

I've read that crystal formation is the root cause of internal resistance, and the way to break this up is by doing a slow discharge (<= 100ma) and a FAST charge.
Although, I'm not exactly sure how fast of a charge is needed.

I've been doing some experiments on several AAA (550-700 mah) batteries that wouldn't charge on my C9000(says 'HIGH'). I've been putting them on my BC-900 at 100ma discharge and as soon as I notice it starting to charge, I pull it out and put it back on for a 700/1000 ma charge. I repeat it once or twice.

So far many of those batteries seem to be able to be charged on my C9000 now.

I also remember reading that a constant current discharge possibly lower than 100ma would be more beneficial in breaking up the crystals than the PWM current of the BC-900(500ma) or C9000(1000ma).

So - I dunno.. There could be something to using the mouse-discharge technique. :shrug:

 

[PeAK]

I've read that crystal formation is the root cause of internal resistance, and the way to break this up is by doing a slow discharge (<= 100ma) and a FAST charge.
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So - I dunno.. There could be something to using the mouse-discharge technique. :shrug:

The neatest part of running down batteries with a mouse is when you get past the "knee" of the discharge curve (i.e. the point at which the voltage drops rapidly for constant discharge). In the case of the mouse, when resting, very little power occurs. When the mouse button is clicked (or mouse moved), a signal is generated and the mouse momentarily draws more current and the voltage drops significantly more. Typically, a momentary 0.5V drop can be seen from a single mouse click during.

If a slow discharge to empty is ideal, as you mentioned, then the draw from operating a mouse might be truly ideal...though slow. Still waiting on the Maha crew for their results.

PeAK

 

[Mr Happy]

I don't know how beneficial it may be as I don't have the patience to find out

I use a Microsoft Optical Mouse 2.0 that seems to run for many months on a pair of AA batteries. Even so I still got fed up with feeding it new alkaline batteries, so now I run it on rechargeables. But several months to drain them is too long for me to conduct any reasonable tests on its use for refreshing batteries...

 

[SkipH]

I scrounged 4 old NiCads from an office I work at awhile back. They were for all practical purposes 'dead'...wouldn't charge up on my older Maha charger (MH-204F).

Last fall, I discovered CPF, and got a LaCrosse BC-900 charger with their batteries and some Kodak LSD batteries to power my 2AA camera and new flashlights .

When I tried to charge up the old NiCads in the BC-900, it said 'nope...', so I did the jumper trick off a good battery to get the voltage up enough so the BC-900 would accept them. That worked and after a couple of refresh cycles, I can use a couple of the Panasonic 500 mAhr batteries to run a 1 AA Microsoft mouse. They seem to last for about 7-10 days, and when I put them back on the LaCrosse charger, them usually take 500 mAhr of charge. I use the 200 mA rate and it works fine.

So I think using sub-marginal batteries is a good way to squeeze a few more miles out of them, as an old 500 mAhr NiCad isn't good for much anyway.

 

[shadowjk]

Mr Happy: Have yo unoticed the MS Optical Mouse 2.0 also runs on just 1AA despite having 2AA battery bay?

 

[Hoggy]

Mr Happy: Have yo unoticed the MS Optical Mouse 2.0 also runs on just 1AA despite having 2AA battery bay?

My Logitech mx-600(IIRC) laser does the same thing. As soon as I insert a battery, it starts working.

Weird, huh? :thinking:

 

[NigelBond]

That might mean that battries are aranged in parallel and the mouse works on 1.5 volts. Anyway I also have an mx-600 and I run it on normal non lsd 2500mah duracells and it seems to run for months. This would take way too long.

 

[Hoggy]

That might mean that battries are aranged in parallel and the mouse works on 1.5 volts. Anyway I also have an mx-600 and I run it on normal non lsd 2500mah duracells and it seems to run for months. This would take way too long.

Yeah.. That's what I was thinking.. About the parallel thing.
I've generally been running it on the worst sets.
I have a pair of VERY old Ray-o-vacs - they're not even labeled, that's how old they are. Tests show they that they are ~1000mah at this point. They run the mouse for 10.47 days under my extreme use here(meaning I try to do anything and everything with the mouse, rather than keyboard (I don't use use the mousing-keyboard-representation thing though.)).

I would test the OP's theory, but my mouse only takes AA's and I only found 1 AA that wouldn't charge on my C9000 due to high impedance(a ROV IC3).
The only batteries that really failed on my C9000 are a bunch of AAA's, but my mouse doesn't take AAA's, so I'm at a loss to test his theory.

EDIT: BTW, I don't think the OP is asking about discharging in a mouse from full charge, but rather further discharging batteries in a mouse AFTER they have been discharged in a C9000(or even BC-900). Is that right, Peak?

 

[PeAK]

Yeah.. That's what I was thinking..
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I would test the OP's theory, but my mouse only takes AA's and I only found 1 AA that wouldn't charge on my C9000 due to high impedance(a ROV IC3).
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EDIT: BTW, I don't think the OP is asking about discharging in a mouse from full charge, but rather further discharging batteries in a mouse AFTER they have been discharged in a C9000(or even BC-900). Is that right, Peak?

Yes, doing the experiment on discharge batteries would speed things up considerably. The "loaded mesurement" on discharge in the C9000 would probably result in it having a bit more life than one similarly discharged in the BC-900...scuze my language...What is the term OP mean ?

I've got to admire the "low power" engineers who manage to squeeze operation with 1 AA battery.

PeAK

 

[TakeTheActive]

...scuze my language...What is the term OP mean ?

GOOGLE: define:OP

2.) (Internet) original poster

Reference: Wiktionary: OP

But, I've seen folks also use it as 'Original Post' (i.e. first post in a thread).

BTW, just FYI, my old eyes, viewing through trifocals, have a difficult time reading your 'unbold orange on white and pale blue' formatting. That's why I tend to use bold with red, green, blue and brown for better contrast. :tinfoil:

 

[Beacon of Light]

I don't know how beneficial it may be as I don't have the patience to find out

I use a Microsoft Optical Mouse 2.0 that seems to run for many months on a pair of AA batteries. Even so I still got fed up with feeding it new alkaline batteries, so now I run it on rechargeables. But several months to drain them is too long for me to conduct any reasonable tests on its use for refreshing batteries...

Get a Logitech 620. It runs with 2 AA batteries, but it will operate on one cell. I still use my 1991 Eveready NiCad AA's. A VX Revolution will run on one cell as well. Either one is an excellent mouse and my personal favorites.

Honorable mention to the VX Nano. One of the reasons I don't like it as much, is you need 2 AAA's and it won't work with just one.

 

[Mr Happy]

Get a Logitech 620. It runs with 2 AA batteries, but it will operate on one cell.

No thank you, I will stick with what I have if it's all the same to you.

The Microsoft Wireless Optical Mouse 2.0 is the most comfortable and convenient mouse I have ever used, it also will operate on one cell, and as I mentioned it runs for months on one set of batteries.

There is nothing wrong with it that would cause me to want anything different, except as I mentioned it takes too long to run batteries down.

 

[Hoggy]

No thank you, I will stick with what I have if it's all the same to you.

The Microsoft Wireless Optical Mouse 2.0 is the most comfortable and convenient mouse I have ever used, it also will operate on one cell, and as I mentioned it runs for months on one set of batteries.

There is nothing wrong with it that would cause me to want anything different, except as I mentioned it takes too long to run batteries down.

If it works, I'd just stick with it too..

But if it ever starts going bad, like double-clicking on things or whatever..
I'd suggest going with a laser mouse - any laser mouse.
I've found that opticals always seem to have that dreaded 'mouse crawl', whether they're corded or cordless - and it always seems to crawl up and to the left.

Ever since switching to a laser, I have not encountered any upwards-left crawling. Unlike when I go to use someone else's optical mouse.. I also go on projects installing computers for the VA and have encountered the crawling time and time again.

My current laser mouse has a tendency to double-click things - and started doing so after only 4-6 months, unfortunately. I think it's a Logitech MX610. So I kind of should be looking for a replacement, but don't want to let go of it quite yet. Kinda like my batteries.
But, I digress..

Just sayin'...

 

[Mr Happy]

I've seen the crawling effect with some optical mice, but never with this one. There doesn't seem to be a problem with double clicking either as the mouse buttons have a very positive (but soft) switch action kind of like those old IBM keyboards.

 

[crofty]

I`ve been removing the batts from my solar lights, they`ve been tourtured enough and now it`s time to recycle them. Out of curiosity I attempt to charge them on my C9000 to see how far the capacity has reduced. A few were rejected so I set them to discharge and tried them again, usually that`s enough to get them charging but no such luck this time.

So I put them in my MX1100 one at a time and after about 20 mins use they would no longer power the mouse, back on the C9000 they go and one of them begins to charge, the other needs a few more goes in the mouse before the C9000 will charge it.

Good thinking PeAK :thumbsup:

 

[TakeTheActive]

I`ve been removing the batts from my solar lights, they`ve been tourtured enough and now it`s time to recycle them. Out of curiosity I attempt to charge them on my C9000 to see how far the capacity has reduced. A few were rejected so I set them to discharge and tried them again, usually that`s enough to get them charging but no such luck this time.

So I put them in my MX1100 one at a time and after about 20 mins use they would no longer power the mouse, back on the C9000 they go and one of them begins to charge, the other needs a few more goes in the mouse before the C9000 will charge it...

What's the VDC displayed during the "Impedance Check" on the C9000 for the ones you've coaxed it to accept?

I'm having the same problem with BRAND NEW, never used, but ~2-3 year old NiCDs from a set of Sears Solar LED Lamps. They're rated 600mAh but the best I can get on the BC-900 is around 300mAh. The C9000 just says "HIGH". I use a 1 AA Superman incandescent flashlight (FREE with a pack of Duracell alkalines years ago) to discharge them after the BC-900 hits 0.9VDC but still can't get the C9000 to accept them like you can.

I also salvaged a pair of AA NiCDs from a ~several year old cordless phone pack (3 AAs with solder tabs in shrinkwrap). One cell was dead so I cut two loose, folded over the solder tabs, added some solder and a little 'artistic' filing, to make a 'button'. Same deal - HIGH on the C9000, ~300mAh on the BC-900. I find it an interesting experiment, attempting to lower the Internal Resistance on *CRAP* cells (no Mission Critical Apps here!). SilverFox has posted SO MANY GREAT TIPS over the years! :thumbsup:

I'm looking to pick up a few NiCD AAs when I find a vendor with something else I also need and reasonable shipping (unless I spot them in a B&M first ).

 

[Mr Happy]

To revive NiCd's that the C9000 rejects, what I would do is get an el cheapo trickle charger like this one and put the cells on it for 5-10 hours or so, discharge on the C9000, and repeat until the C9000 accepts them.

Any timed charger with a charging current of 100 mA or less will do the job, or even a home brewed apparatus with a 12 V DC power supply and a 100 ohm series resistor.

You basically want to do a manually controlled version of the break-in charge that the C9000 would do if only it wouldn't be so sensitive.

 

[PeAK]

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So I put them in my MX1100 one at a time and after about 20 mins use they would no longer power the mouse, back on the C9000 they go and one of them begins to charge, the other needs a few more goes in the mouse before the C9000 will charge it.

Good thinking PeAK :thumbsup:

At the time, I was thinking that "fuller" discharge (until a low power device failed) was better, but now I'm not so sure. Here is some info from the eneloop User Guide:
Cause 3 Over-discharge.

"If eneloop batteries are used in low-current applications, there
may be a voltage cutoff point below which eneloop cannot
power the application (e.g. a flashlight). When the eneloop's
voltage falls below the cutoff point, the flashlight will go out,
but eneloop batteries will continue to discharge, as the circuit
is not broken. Consequently, a film will develop on the terminals
due to inactive electric current, and the eneloop battery
will become inactive. To fix the problem, drain the batteries in
a high-current application (e.g. a digital camera) until the battery
is empty, and then recharge it."

(Page 8 of Eneloop User Guide)
​

The only thing different in a digital camera is that it also has a voltage cutoff circuit but one that initiates a shutdown cycle to completely remove low level current draw which the User Guide is cautioning against. A mouse may be different in that the cutoff point goes down until the battery is truly exhausted whereas the flashlight cutoff always goes to the same point...and then some (like a mouse). Confusing when you think about the Maha approach of doing it under load (i.e. higher current draw).

My other issue is that my mouse uses 2 batteries and in this case, I think I see one battery drop before the other and suffer cell reversal. Come to think of it, maybe the Sanyo engineers were seeing cell reversal issues in high powered flashlights with voltage cutoff circuits that remained ON.


PeAK