Microsoft 3500 mouse short battery life fix - Page 1
Forum section: electronics / general

author: Kaptein QK
author_rank: Regular Contributor
timestamp: November 22, 2013, 10:59:08 pm
content: My mouse was difficult to turn on even if the battery had 1.4V left on it. If I tried several times it finally stayed on. If I left it on, it worked a few weeks longer, and when it turned itself off again the battery had about 1.1V. It had a battery life far away from the claimed 8 months.I measured the current drawn from the single AA battery:First 14 seconds after turning on, green LED lit: 140mA (!!) This causes the battery voltage to sag below the cut-of voltage unless the battery was fresh, and turn off the mouse.Moving: 15mAIdle: 0.7mALow battery warning, red LED: 90mA. I never saw the warning light, because the increased current immediately drags the voltage below to cut-off limit and it turns off.It turns out the LEDs where driven from 4.5V from a DC/DC converter and wasting a lot of power through the limiting resistors. The main blue sensor illuminating LED is also driven from the same source, but this makes sense due to the higher Vf of the blue LED.The solution is to disable the LEDs by removing R8. See the attached schematic below. Also see the location of the removed resistor, it is close to the crystal.I did this fix on two mice, and a search shows there is others having the same issues with it.Besides above issues it is a very good mouse, it wakes up from deep sleep very fast, and there is no noticeable lag.

author: backflipper
author_rank: Contributor
timestamp: November 23, 2013, 12:53:24 am
content: Nice work.So is the green LED just leaky and causing the excess current or am I missing something else?

author: SeanB
author_rank: Super Contributor
timestamp: November 23, 2013, 06:06:28 am
content: I would guess there is a software bug that does not enable the PWM properly. Simple to disable by replacing Q3 with a 4k7 SMT resistor connected between collector and emitter to limit current to a low level. The LED's will be bright enough at this low current to see, and then it will work fine.We have some at work and they do last well, must be a firmware version that had this problem and we dodged the issue with ours.

author: amyk
author_rank: Super Contributor
timestamp: November 23, 2013, 06:35:14 am
content: I never understood the purpose of decorative LEDs on hamsters. All they do is waste battery (and maybe help you find it in the dark?)

author: SeanB
author_rank: Super Contributor
timestamp: November 23, 2013, 07:08:13 am
content: I prefer the wired type, you can never misplace it. I have a large collection of white Intellimice that are a decade or more old. Only thing that fails is the cord ( easy to replace/repair as it always breaks at the rodent end) and the left mouse button wears out. Buttons are easy to get that will fit with either a little work or they drop right in.

author: Kaptein QK
author_rank: Regular Contributor
timestamp: November 23, 2013, 11:08:19 am
content: Quote from: backflipper on November 23, 2013, 12:53:24 amNo, the LEDs is driven inefficiently from a high voltage, and the DC/DC converting process multiplies the current drawn from the battery by the same factor as the voltage is multiplied from 1.5V to 4.5VSomewhat related video:

author: Kaptein QK
author_rank: Regular Contributor
timestamp: November 23, 2013, 11:19:48 am
content: Quote from: SeanB on November 23, 2013, 06:06:28 amI do not see the need for LEDs on a mouse. Either it works or not, pretty easy to notify.By using high quality alkaline battery and never turn it off it last a fair amount of time, but this fix enables you to use batteries with a low state of charge or lesser quality. (It will not turn on with certain batteries even if they are new) Also it should give some additional time since the low battery warning LED kills the remaining battery capacity.Have you ever seen the low battery warning on yours, or do they just suddenly die?

author: SeanB
author_rank: Super Contributor
timestamp: November 23, 2013, 11:26:45 am
content: I do not use wireless ones, always a wired one. they come with a long enough cable so any desk will take them even in a cable tidy.Only ones who want the wireless ones are those who have so much clutter that the cable becomes tangled up in it. Red LED tells you that the thing is plugged in, and that the USB port is powered up (if off then the laptop has gone into deep sleep and turned off USB) so that shaking will wake up the computer.

author: Zbig
author_rank: Frequent Contributor
timestamp: November 23, 2013, 09:06:56 pm
content: Quote from: SeanB on November 23, 2013, 11:26:45 amWow, I wouldn't think I'll ever meet someone who actually prefers wired mouse (well, apart from some hardcore gamers, that is)From my experience, no matter how tidy your desk is, a corded mouse will actively seek for anything it could get caught on as soon as you look away for a second and will invariably succeed to do so every single time with 100% effectiveness. Pretty much the only thing I could imagine worse than a corded mouse is an ancient "balled" corded mouse which, as if it being a corded mouse wasn't bad enough, required thorough cleaning after every two hours of usage. Or so I remember (trying to forget, though).

author: Kaptein QK
author_rank: Regular Contributor
timestamp: November 23, 2013, 10:24:39 pm
content: You don't like cleaning balls?

author: peter.mitchell
author_rank: Super Contributor
timestamp: November 24, 2013, 05:56:01 am
content: Quote from: Zbig on November 23, 2013, 09:06:56 pmI'm with SeanB on this one, the batteries on a corded mouse never go flat, and if they do, you've got other, bigger problems that will stop you using your computer, you never have any possible issues with interference, and as far as movement goes, generally, mice should be configured as such you can move your cursor from one side of the screen to the other without moving your arm, all in the wrist...My desk is a mess, no doubt about it, and i have no issues with the cord catching on anything. *shrugs*

author: amyk
author_rank: Super Contributor
timestamp: November 24, 2013, 06:09:47 am
content: I prefer the ones with tails too.

author: Towger
author_rank: Super Contributor
timestamp: November 24, 2013, 08:55:16 am
content: Quote from: amyk on November 24, 2013, 06:09:47 amSo do I. Notting worse than unreliable equipment.

author: SeanB
author_rank: Super Contributor
timestamp: November 24, 2013, 09:03:30 am
content: Mouse mat and the cord drops off the desk to the left of it with a loop so there is no cord to catch. No laggy mouse, no problems from QRM, no looking for spare batteries and no having to dig behind the computer for the dongle to press the *$%^&@$^^&%! button to repair it when it decides to disconnect.Most important is the low cost, I have never bought a mouse for myself, they were all free from others "upgrading" to the new flashy black or cordless ones. Most expensive I bought was for $10, for my sister to replace the one with a ball. Still have some around though, useful with serial ports or proper keyboard mouse motherboards.

author: peter.mitchell
author_rank: Super Contributor
timestamp: November 24, 2013, 10:28:40 am
content: This is how i see wireless anything;Until you can control the reliability of the medium your signal is transmitted through, you should consider the reliability of the signal as uncontrollable.

author: IanB
author_rank: Super Contributor
timestamp: November 24, 2013, 11:37:40 pm
content: I stopped using corded mouses long ago. The main issue is that the cord catches and prevents the free movement of the mouse. I want freedom to move my mouse without some weight or pull or tension dangling off the end of it and adding friction. There's nothing worse than attempting pixel precise positioning and having something tugging on the mouse just at the wrong moment.I use a Microsoft Wireless Mouse 5000 which is full size, has a nice feel, and has the blue LED for precise movement.I don't have any issues with battery life as I use rechargeable batteries in anything like that and the batteries last months on a single charge in any case.

author: Zbig
author_rank: Frequent Contributor
timestamp: November 25, 2013, 06:51:56 pm
content: Quote from: IanB on November 24, 2013, 11:37:40 pmThis.EDIT: This model uses two AA cells wired in parallel so you can work with one only in an emergency as an added bonus.

author: GreyWoolfe
author_rank: Unknown
timestamp: November 25, 2013, 08:07:06 pm
content: On my work and home computer (KVM switch) and my workbench computer, I use wired mice and keyboards. I also use under desk mounted articulated keyboard/mouse trays. On my Ham Radio desk, I use a Logitech Wave 2.4 wireless keyboard/mouse as I want the desk clean and don't want anything to tangle up in my headset/boom mic cord. All mice are laser mice so no more cleaning my balls in my office.Tom, NW0LF

author: Kaptein QK
author_rank: Regular Contributor
timestamp: December 19, 2013, 11:49:41 pm
content: I wanted even more out of the batteries, especially the NiMH was only partially drained at the 1V cut off.I found the two resistors responsible for dividing the battery voltage and sending it to the uC, presumable to an ADC.It is R30 and R33. I simply removed the bottom voltage divider resistor, R33.Now the cut off is about 0.5V, but the mouse only work down to 0.8V, effectively making it the new LVC.Now the NiMH drains 100%

author: thm_w
author_rank: Super Contributor
timestamp: December 20, 2013, 11:53:19 pm
content: Quote from: IanB on November 24, 2013, 11:37:40 pmCan use mouse bungee or similar to suspend cord:http://www.newegg.ca/Product/Product.aspx?Item=N82E16826999092

author: TheBay
author_rank: Unknown
timestamp: December 21, 2013, 01:15:55 am
content: My "Intellimouse" bought in 2000, still use it today, though I still consider it new LOLQuote from: SeanB on November 23, 2013, 07:08:13 am

author: andtfoot
author_rank: Unknown
timestamp: December 21, 2013, 02:09:15 am
content: Quote from: thm_w on December 20, 2013, 11:53:19 pmI just cable/velcro tied the cord to the monitor stand with a bit of slack and never had an issue.

author: SeanB
author_rank: Super Contributor
timestamp: December 21, 2013, 06:01:44 am
content: Quote from: TheBay on December 21, 2013, 01:15:55 amI only have one of those, most are the older 2 button wheel mice. The cases are not too white any more from years of use, and the label on the bottom is long gone on most, along with those little slider feet.

author: peter.mitchell
author_rank: Super Contributor
timestamp: December 21, 2013, 06:31:43 am
content: Quote from: IanB on November 24, 2013, 11:37:40 pmI guess a fair amount comes to personal preference, but I regularly hear that optimal mouse sensitivity should be that you can move the cursor from one side of your monitor to the other, without moving your arm, so the cord is generally a non issue.

author: Zbig
author_rank: Frequent Contributor
timestamp: December 22, 2013, 06:23:29 pm
content: Quote from: Kaptein QK on December 19, 2013, 11:49:41 pmYou'll ruin your NiMH's this way - discharging them below 0.9V is detrimental to this type of chemistry.

author: Balaur
author_rank: Unknown
timestamp: December 22, 2013, 06:28:03 pm
content: Quote from: Zbig on December 22, 2013, 06:23:29 pmI wanted to say the same stuff, but individual NiMh cells are not that adverse to total discharge. It's the reverse charging that kills them.In addition, the mouse stops working at 0.8V, so it's safe(ish).

author: IanB
author_rank: Super Contributor
timestamp: December 26, 2013, 09:37:17 pm
content: Quote from: Balaur on December 22, 2013, 06:28:03 pmI agree. Taking a single NiMH down towards zero won't really do any harm, so if the mouse is one of the kind that has two 1.5 V batteries in parallel then reducing the low battery cut-off is no problem. What is odd is why there would even be a low battery cut-off circuit in the first place? Why not just let the mouse run until it doesn't work any more? (One cynically imagines that the electronics manufacturers collude with the battery manufacturers to help sell more batteries.)On the other hand, when one looks at the discharge curve of an NiMH battery there is precious little energy left once the voltage is below 1.0 V. I find it hard to imagine there is much to gain by extracting the last few mAh...?