I posted this in one of the "Edge 130 battery is terrible and sucks" threads, but there are so many battery threads I wanted a dedicated thread in case it would help someone specifically interested in an external battery.
I used the smallest "liptstick" battery I could find, which is still over 10 times the capacity of the factory Edge 130 battery. If a smaller one was available, it would make the install a little less unsightly, but I've grown to love my ugly duckling batteries. I've permanently mounted one on each of my two mountain bikes and now that I've been using them for about 6 weeks, I'm thrilled with the results. Even with long night rides below freezing, no more battery angst.
For some it is a bodge. I get it. If it's not for you, move on, nothing to see here. I'm very competently able to tear open my 130 and do the battery upgrade, but this just appealed to me more. Easier, no risk of damaging my 130 as could happen with the battery mod, and more than 10 times original battery capacity. I now use my backlight on high during below freezing night rides as much as I want. Six weeks in, I've yet to need to charge either lipstick battery. More on that later.
The install, in pics:
Picture above shows the white lipstick battery zip-tied to the stem. The key to it being very secure is the self adhesive foam weatherstripping which allows the base to follow the contours of the stem and grip it. (Self adhered to the battery, not the stem.) I've done multiple rough rides on this hardtail with zero movement of the battery. Grey foam weatherstripping can be seen following the contours.
This top view shows the Garmin mount that needed to be clearanced in the front for the charge cable to clear. Five careful minutes with a Dremel took care of it.
This is my other bike which was my second install, where I wrapped the battery with electrical tape just so it blended in better. This shows the "start of ride" condition where I have connected the charge cable to the Garmin but not the battery. It isn't good for lithium batteries to stay at full charge, so I start the ride on the Garmin battery alone. During that time I have both ports of the battery plugged. I also have a cap with a tether over the battery end of the cable to keep it clean and prevent it from flopping around.
Once the Garmin shows it's down to 40% battery remaining I stop, remove the battery USB cover and plug in the lipstick battery. Cable cap tether can be seen dangling.
Lithium batteries last longer if kept between 40% and 80% charged. By using the external battery pack I'm no longer trying to charge the Garmin itself to the maximum. By letting the lipstick battery get partially depleted with each ride, I'm ensuring I'm not charging the Garmin itself too much. I'll recharge the lipstick after it struggles to keep the Garmin at 80%. After two rides the Garmin battery percentage jumps from 40% to 80% when I plug in the lipstick battery.
And finally, just a shot of the back of the battery showing it's the small (2200mAh) battery. Small for charging a cell phone. Ginormous for what an Edge 130 needs!
So, I hope this helps someone with Edge 130 battery angst. The battery was causing me deep buyers remorse pain but now I am perfectly happy with my setup. I now feel quite smug looking at my nice bright backlight set at high during my long, cold night rides!
