Are NiMH Batteries OK to use?

[Pyromancer]

Nickle Metal Hydrate batteries. (Rechargeable)
I currently have the Palm m125, and I know the user manual says to only use Alkaline Batteries in this unit. However, that is usually just put in there to clarify that other types may not be compatible. I've used NiMH batteries in other devices that say only to use Alkaline and they've worked fine.
I'm just wonder if anyone has had any real problems with using them. I'm going to put them in tonight if no one says otherwise, anyway.
Yep, well. Thank you.

[Masterchief]

The NiMH batteries will probably work fine. I know people who use recharable batteries on their PalmPilots and have had no trouble with them. In some rare occasions , I've seen some recargeable batts leak but you should be fine. Just don't get the cheapest ones out, because they are of less quality and you won't get much use out of them.

[lectraplayer]

That's what I hate about my M125 the most. It just don't work at all with NiMH or NiCd batteries. You must use Alkalines. NiMH & NiCd batteries operate at a lower voltage & just aren't strong enough to push a M100 series Palm. I tried & it did nothing, and it is the only thing that has done that. That's enough to make a preacher cuss (especially if he thinks like I do).

[s1223]

I have used NiMH batteries in my palm m100 for a while and it works fine.

[Masterchief]

What is the max. voltage that your batteries use? I wonder how much is needed to power a Palm.

[Diesel]

I have just started using NiMH batteries in my M125 and am very happy so far with the results. I had to do a soft reset after putting them in. I changed the first set after a few hours use to see if I would have any problems with the Palm, it started back up with no problem. I installed "Battery Panel" which allows you to change the battery type to NiMH. It looks like the built-in battery gauge is not working as it has not moved off full charge but I still get the actual voltage from Battery Panel.

According to "Battery Log" I have used them over 5 hours so far including 35 minutes with the backlight on. They are rated at 1.2 volts and are 750mah capacity. I checked them with a battery meter before installing and they came out of the charger at 1.4 volts. The current voltage reading on my Palm is 2.67 volts which if correct means they are not discharging very fast.

[lectraplayer]

I am also trying NiMH, but mine doesn't work. As a matter of fact, this time I had to do a hard reset to get it to work again with my Alkalines. Though I know a Palm handheld doesn't use much power, it does take a unusually high voltage to be powered like they power it. Fortunately, a quick Hotsync restores my data. ..and Consumer Reports says it don't come with backup software... Aparantly, your batteries (this time) are unusually strong. They may not work reaiably (because they might charge to a slightly diferent voltage each time). Only time will tell. Keep me updated. If you're still getting 2.7V or somewhere about, your battery gauge is working fine. I expeced mine to read about half a charge, but it registers nothing (the device don't even work.

[Ben S]

I've successfully used AAA NiMH (1.2V/cell) batteries on every AAA-powered Palm I've ever had. Lectraplayer, how many pairs of cells have you tried? Have you tried different brands?

[dkhaw]

I have a M100 and have just switched from Rechargable Alkalines to Nimh 2 weeks ago. I must say that the Nimh are way better for me because of the lower internal resistance and therefore higher current. That's good especially if you have CPU intensive applications or use the backlight often. The rechargable alkalines drop their voltages really fast when I leave my backlight on; not so for the Nimh. However, if you are use your palm lightly, never run any CPU intensive programs and rarely use your backlight, then the Rechargable Alkalines might be a pretty decent choice. Also, they have a much lower rate of self-discharge and therefore, do not lose their charge as quickly as the Nimh. I have never tried disposable alkalines before so I can't really compare.

I used to use "Pure Energy" Rechargable Alkalines ( http://www.pureenergybattery.com ) for about 7 months. Now, I use "GP" 750mAh Nimh ( http://www.gpbatteries.com.hk) ; that's probably the highest mAh rating I have seen for AAA batteries. The higher the mAh, the greater the juice and longer your palm will last. I use the shortcut.7 to change the battery meter to Nimh. This not only calibrates the battery meter but also sets the warning voltage to 2.33 volts. I installed a battery log hack and got the following results:

Total time: 11 days +
Total power on time: 13 1/2 hrs
Total Backlight on time: 3 1/2 hrs + !! (that's close to 4 hours!)

At this point in time, I still had about 15 % battery left and the voltage was at 2.37v. The battery warning never came on since it is set at 2.33v. I probably could have gone on for another hour or so. However, knowing that Nimh have a very steep discharge curve pass the critical voltage and being my first time using Nimh, I decided to change it. The next time, I would probably push it until I get the low battery warning message. Everything on my palm is backed up of course!

Overall, I am very impressed with the battery life of the Nimh. For my kind of usage, it beats the Rechargable Alkalines.

[kahouse]

Originally posted by Diesel
I have just started using NiMH batteries in my M125 and am very happy so far with the results. I had to do a soft reset after putting them in. I changed the first set after a few hours use to see if I would have any problems with the Palm, it started back up with no problem. I installed "Battery Panel" which allows you to change the battery type to NiMH. It looks like the built-in battery gauge is not working as it has not moved off full charge but I still get the actual voltage from Battery Panel.

When you use something other than alkaline batteries with your Palm, the battery gage will not be correct because it is made for alkaline batteries. However you can use the memo pad shortcut (shortcut dot 7) to switch between battery types so that the gage will show the correct battery power.