Eneloop PRO problems with GPSMAP 66s

Discussion related to the Garmin GPSMAP 66s/st GPSr
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MTB75
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Joined: Mon Sep 13, 2021 4:42 am

Eneloop PRO problems with GPSMAP 66s

Unread post by MTB75 »

Just replaced 64s model with 66s. I installed eneloop pro batteries and device won't boot. Tried two different pairs. Voltage is 2.6V. FW 7.60.
Replaced with alkaline batteries, everything works fine. Switched accu settings to NiMh / NiMh precharged, no difference.
Batteries worked fine in 64s and they are charged so I guess they are not problematic.
Any idea?
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GPSrChive
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Re: Eneloop PRO problems with GPSMAP 66s

Unread post by GPSrChive »

Did you install them with proper polarity?

Have not heard anything like this before and have never had issues with any NiMH batteries in any Garmin GPSr.
MTB75
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Joined: Mon Sep 13, 2021 4:42 am

Re: Eneloop PRO problems with GPSMAP 66s

Unread post by MTB75 »

Of course I did. Tried few times.
Very strange. :geek:
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GPSrChive
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Re: Eneloop PRO problems with GPSMAP 66s

Unread post by GPSrChive »

I might have guessed one of the batteries had an issue, but you stated you tried another set with identical results.

Can you try a different brand of NiMH for testing purposes? I have had great success with the Amazon house brand.
MTB75
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Joined: Mon Sep 13, 2021 4:42 am

Re: Eneloop PRO problems with GPSMAP 66s

Unread post by MTB75 »

Tried brand new Ikea Ladda yesterday and everything works fine.
Also tested all batteries in smart charger. Old eneloops pro still have good capacity (>2300 mAh) but higher internal resistance (140-180 milliohms) compared to new ladda (45-50 milliohms).
It is interesting that eneloops worked fine in GPSMAP 64s.
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GPSrChive
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Re: Eneloop PRO problems with GPSMAP 66s

Unread post by GPSrChive »

Very interesting test results!

Please let us know what happens when you test with new Eneloops, and what their internal resistance measures.
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