Traditional NiMH vs. Precharged NiMH

Discussion related to the Garmin GPSMAP 65 series GPSr
Post Reply
0x01
Posts: 67
Joined: Tue Apr 13, 2021 2:13 pm

Traditional NiMH vs. Precharged NiMH

Unread post by 0x01 »

Hello,

since my first day I wonder what is the difference in the battery settings.
I am using NiMH batteries with low self discharge (e.g. eneloop).
Shall I select traditional or precharged setting?

Both settings seem to be inaccurate in terms that the first two bars drain fast and then the one last bar remains for long until the unit powers off due to low battery. I am using two different battery brands (not at the same time).

Thanks & regards
0x01
GPSMAP 65s | eTrex Legend HCx
User avatar
GPSrChive
Site Admin
Posts: 3881
Joined: Fri Jan 20, 2017 11:29 pm

Re: Traditional NiMH vs. Precharged NiMH

Unread post by GPSrChive »

Early rechargeable AA batteries were not sold or distributed pre-charged and ready to use out of the package primarily because the engineering for this purpose had not yet been completed. Improvements in battery chemistry and design eventually resulted in pre-charged ready to use out of the package rechargeable batteries quickly becoming the standard, but the latter continued to be sold at lower expense.

Early rechargeable AA batteries would self discharge over a short period of time, leading to the development of 'low self discharge' batteries that could retain the majority of their charge when not used for an extended period of time. These 'LSD' batteries could then be pre-charged at the factory and used by the consumer directly out of the package without first being charged like the traditional rechargeable batteries of the time.

Both battery types have unique charge and discharge curves, therefore the GPSr needed to have options for each to ensure the battery charge indicator was as accurate as it could be, which is already not very detailed when using AA battery cells.
Garmin Support wrote:
Traditional NiMH
These batteries must be charged before their first use and have a higher rate of self-discharge when compared to pre-charged NiMH batteries, meaning they may need to be recharged more often between uses.

Precharged NiMH
Sometimes advertised as "Ready-to-Use" or "Low Self-Discharge" (LSD), these batteries have a significantly lower rate of self-discharge when compared to traditional NiMH batteries. This means that they will retain their charge for longer between uses.
Source
Your GPSr should be configured for 'Precharged NiMH' when used with your LSD eneloop batteries.
0x01
Posts: 67
Joined: Tue Apr 13, 2021 2:13 pm

Re: Traditional NiMH vs. Precharged NiMH

Unread post by 0x01 »

Thanks for clarification. "Precharged" is not known for those type of batteries here in Germany. They all are advertised as "low self discharge".
GPSMAP 65s | eTrex Legend HCx
Themistokles
Posts: 45
Joined: Sun Jun 30, 2019 7:47 am

Re: Traditional NiMH vs. Precharged NiMH

Unread post by Themistokles »

@0x01

Did you find a solution to your problem?

You have been advised to choose "Precharged NiMH" in the settings. But in your first post, you have stated that the battery status indication does not work as expected regardless of that setting ("Precharged NiMH" vs. "NiMH"). Therefore, if you have solved the problem, I assume that this needed more than that setting.

I would be grateful if you could describe your solution. The reason I am asking is that I have the same problem with my Montana 700. After 30 to 60 minutes with freshly charged NiMH batteries, the battery status shows only one bar and the red LED of the device begins to blink; however, the device continues to work for the time we could expect (six hours or so). In other words, the battery status indication is useless for me.

Thank you very much in advance!
0x01
Posts: 67
Joined: Tue Apr 13, 2021 2:13 pm

Re: Traditional NiMH vs. Precharged NiMH

Unread post by 0x01 »

I take a 2nd pair of batteries with me, or start with fully charged ones.
Reliable is the explicit popup notification for low battery - the unit will shut off very soon then.
GPSMAP 65s | eTrex Legend HCx
Post Reply

Return to “GPSMAP 65”