Hi Folks,
Just to make you aware about a simple upgrade possible on your 695/696 Garmin GPS.
I found the alternate source for NiMH battery packs, from medical monitors, but while this is the 100% perfect replacement part, battery lifetime of the 695/6 is not so great, specifically when you bump up thebacklight to 9 or 10 level.
nIMH also tend to age rapidely, and you endup with a poor autonomy. And they also self discharge fast.
I did swap the battery cells to Li-Ion. I use 4 18650 cells, in 2S/2P configutation. This means 2 cells in parallel, and eacn double cell in series.
this way, using Samsung 3450mAh cells, you get about 7000mAh, which is almost twice the 3800mAh of the genuine niMH pack.
Those cells do fit nicely in the original battery box.
Of course, you need to add : a passive balancing module, to be sure that when charging, all cells are properly balanced.
I picked that one, a 2S 20A module :
https://fr.aliexpress.com/item/1005...id=2022123102164717926849766277480015574719_1
You also need a dedicated USB charging module. I pick up that one on Aliexpress. 2S and 2Amps. Not above, as 4 amps is heating too much.
https://fr.aliexpress.com/item/1005...00030900317118!sea&curPageLogUid=LqKHKgtgRHw0
Using a dremel, you just have to make a small hole in the bottom of the battery case to fit in the USB C plug. Charging will ONLY be done through that USB C plug. The 4 pin Garmin plug, and the USB are not used anymore, and this is great for those who actually broke those plugs!
Lastly, to get the right calibration of the battery gauge on the screen, there is one modification / resistor replacement to be done on the battery pack PCB. There is a large 2512 SMD resistor of 15mOhm. This needs to be changed to a 8mOhm resistor.
a link is there :
https://fr.aliexpress.com/item/1005...t_main.86.3f5f5e5bAg0bpt&gatewayAdapt=glo2fra
This is to fool the battery bq2019 gauge sensor IC, and get him to beleive the battery capacity is unchanged, while we did change it. This is the only way I managed to get the battery gauge to be precise. I even read the battery chip memory content, and looked at increasing the battery capacity there, but the 695 software cannot cope with that, and overwrites the battery capacity in Coulombs back to 13680...( 3800mAh = 13680 Cb) as soon as the GPS is powered up.
With all that, you get a nicely 695/6 with up to 7 hours battery lifetime , very little autodischarge.
The only thing is :
1 - always use the new USB C port to charge the GPS
2 - always turn it on to get it charged, as otherwise, the battery gauge / level is not updated.
I will post below pictures and schematic of what I did.
Cheers!
Just to make you aware about a simple upgrade possible on your 695/696 Garmin GPS.
I found the alternate source for NiMH battery packs, from medical monitors, but while this is the 100% perfect replacement part, battery lifetime of the 695/6 is not so great, specifically when you bump up thebacklight to 9 or 10 level.
nIMH also tend to age rapidely, and you endup with a poor autonomy. And they also self discharge fast.
I did swap the battery cells to Li-Ion. I use 4 18650 cells, in 2S/2P configutation. This means 2 cells in parallel, and eacn double cell in series.
this way, using Samsung 3450mAh cells, you get about 7000mAh, which is almost twice the 3800mAh of the genuine niMH pack.
Those cells do fit nicely in the original battery box.
Of course, you need to add : a passive balancing module, to be sure that when charging, all cells are properly balanced.
I picked that one, a 2S 20A module :
https://fr.aliexpress.com/item/1005...id=2022123102164717926849766277480015574719_1
You also need a dedicated USB charging module. I pick up that one on Aliexpress. 2S and 2Amps. Not above, as 4 amps is heating too much.
https://fr.aliexpress.com/item/1005...00030900317118!sea&curPageLogUid=LqKHKgtgRHw0
Using a dremel, you just have to make a small hole in the bottom of the battery case to fit in the USB C plug. Charging will ONLY be done through that USB C plug. The 4 pin Garmin plug, and the USB are not used anymore, and this is great for those who actually broke those plugs!
Lastly, to get the right calibration of the battery gauge on the screen, there is one modification / resistor replacement to be done on the battery pack PCB. There is a large 2512 SMD resistor of 15mOhm. This needs to be changed to a 8mOhm resistor.
a link is there :
https://fr.aliexpress.com/item/1005...t_main.86.3f5f5e5bAg0bpt&gatewayAdapt=glo2fra
This is to fool the battery bq2019 gauge sensor IC, and get him to beleive the battery capacity is unchanged, while we did change it. This is the only way I managed to get the battery gauge to be precise. I even read the battery chip memory content, and looked at increasing the battery capacity there, but the 695 software cannot cope with that, and overwrites the battery capacity in Coulombs back to 13680...( 3800mAh = 13680 Cb) as soon as the GPS is powered up.
With all that, you get a nicely 695/6 with up to 7 hours battery lifetime , very little autodischarge.
The only thing is :
1 - always use the new USB C port to charge the GPS
2 - always turn it on to get it charged, as otherwise, the battery gauge / level is not updated.
I will post below pictures and schematic of what I did.
Cheers!
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