Registered: Dec 2000
Location: Bonn, Germany
Posts: 55

Energizer NiMH Rechargables

Okay,

I'm running on a VDX using Energizer ACCU batteries, which are rechargeable NiMH cells.

So far they work beautifully. The charge isn't as smart as I'd like (takes 15 hours, doesn't have any sort of "top off" feature), but they batteries last longer than energizer e^2 as far as I can tell without studying it, and all I have to do is have a charged pair handy. It's great.

I have the Visor set for NiCD, which is the closest profile.

My problem is really that the percent seems disturbingly nonlinear and sporadic, even when voltage is near constant. Example: I got a low battery warning at around 2.36 volts, but the percent read 10% for a second, then said like 50%, even though the voltage stayed at about 2.36ish

What I would like to know is if anyone has a patch that changes the formula for NiCD to be like NiMH, or if someone has an app, that shows me how much juice is left. I am cool with watching the Voltage, because it's more reliable, but I would like to have an idea when I will be out.

Another odd thing is that switching the batteries seems to require a soft reset. This may be unrelated to the new battery type but it is weird.

Any experiences?

Thanks,
Kg

Registered: May 2000
Location: St. Paul, MN
Posts: 1429

There are many hacks/apps out there for this purpose. Unluckily I do not remember any, since I've been on a Prism for awhile. Do a search on palmgear, and look for battery, or battery manager. ATool comes to mind, but I don't know if that is the right one.. They readily exist though!

Also, whatever kind of battery your using - the percentage left is based on the amount of volts the visor is using. So if you just go back from a springboard app, or a processor intensive thing, the battery monitor hasn't refelcted this. This behavieor is expecially rflected the less battery voltage there is in the battery - the profile doesn't help this TOO much.. sorry Well.. at least in my experience.

__________________
-miradu

Registered: Dec 2000
Location: Bonn, Germany
Posts: 55

Thanks,

I've found that while there a bazillion hacks and apps out there, just about none of them actually change anything but the critical values, or GUI stuff.

Oh well.

Your comment about the relativeness of the battery percentile is also true to my experience, and I should have been thinking about that anyway. As it is I've kind of figured out that when it budges from %100, that means it is half spent

Kg

Registered: Jul 2001
Location:
Posts: 12

FIX NIMH

I have used NIMH batteries for a while now and they work great. The only problem is that since they do not behave the same as Alkaline batteries, the voltage display is inaccurate. However, PALM OS has a built in feature that will fix this. Just go to a text editor (I use the memo app) and start a new memo, then enter "shortcut"(this character is kind of like a lower-case "l" in cursive, it is in the Graffiti reference), ".", "7" until it displays "[NIMH]". You do not need to save this memo, but you will need to re-enter this command if you have a hard reset, or complete power loss.

NOTE: NIMH batteries will sustain maximum voltage until just before they are empty, then the voltage will drop off sharply, so once it gets down to about 30% change the batteries or you might loose your information.

Registered: Jan 2001
Location: Misplaced Canuck in Charleston SC
Posts: 257

Re: Energizer NiMH Rechargables

quote:

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Originally posted by kgruscho
Okay,

Another odd thing is that switching the batteries seems to require a soft reset. This may be unrelated to the new battery type but it is weird.

Any experiences?

Thanks,
Kg

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Registered: Dec 2000
Location: Bonn, Germany
Posts: 55

the ..7 is the NiCD profile I was refering to in my original post.
OS3.1 only has alkaline, alkaline rechargeables, and NiCD profiles.

The critical voltages for NiCD and NiMH are identical, but the "percentage" doesn't match up well.

What I was refering to was that on my system, set for NiCD using .7, when it finally drops below %100, then it is about half spent.

I am starting to think this may be because I am using 700mA or "Hi-Energy" NiMHs. They are really great, but I'd like to be able to discharge the batteries fairly completely before removing them from the Visor, which is dangerous to do when it goes from 50% to 10% (according to the OS) in about 30minutes of user time, doing nothing but playing games and checking addresses.

It's not worth it to do me what some people do, which is discharge the remainder of the charge in a mag lite. NiMHs have no or negligible "memory" effects, so I figure that it's fine to pull when it warns, and then recharge some. I just think I am frying the batteries with my dumb recharger.

Thanks,
Kg

Registered: Dec 2000
Location: Bonn, Germany
Posts: 55

the soft reset bit is weird

I put in the batteries and it shows the screen like it was, but does not respond.

reset and evertything runs great.

Kg

Registered: Jul 2001
Location:
Posts: 12

.7

Maybe the .7 setting for NIMH is only avaliable in OS 3.5.2 (I have a Platinum and there is an NIMH setting on mine). Also, yes NIMH and NICAD are similar except for their discharge rates. NICADS discharge gradually like Alkalines (only faster), but NIMH batteries stay at their full voltage until they are almost drained then they drop off quickly (that is why they are better for electronic devices that have tight voltage and current requirements).

Also, I use Rayovac NIMH batteries that I got from Wallmart, but I doubt that there is much difference between them and the Energizer ones.

Registered: Jan 2001
Location: Misplaced Canuck in Charleston SC
Posts: 257

Re: .7

quote:

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Originally posted by quasihuman
Maybe the .7 setting for NIMH is only avaliable in OS 3.5.2 (I have a Platinum and there is an NIMH setting on mine). Also, yes NIMH and NICAD are similar except for their discharge rates. NICADS discharge gradually like Alkalines (only faster), but NIMH batteries stay at their full voltage until they are almost drained then they drop off quickly (that is why they are better for electronic devices that have tight voltage and current requirements).

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-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GS d-(+) s: a C++ UX++++V++S++ P+>+++ L>+++ E+>++ W++ N++(+++) o? K? w !O !M V-- PS PE Y+ PGP++ t++ 5++ X++ R+ tv++ b++(+++) DI++++ D+ G++ e+++>++++ h--- r+++ y?
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