DonFrambach

Going on a double century next week and purchased an external battery for my Garmin 705 which uses 2 AA NiMH batteries. I suppose it will work fine if I tape the battery door shut before I mount it to my bike.

It occurred to me that I have an extra Lithium ion battery for my Dinotte lights which is in a nicely sealed container that is easily attached to my bike (and, I believe, with larger capacity than 2 AA batteries). Has anyone used such a battery with their Garmin GPS? Maybe not for this ride but it seems to me that the Dinotte battery might be a better solution.

ekincam

What size of li-ion battery? If these are AA size such as Energizer E2 then you can swap them in but you may not see a huge benefit from using them other than that the lithium batteries weigh about half as much as similar size NiMH.

The li-ion and lipo batteries I usually see are 3.6V or a multiple of that if this is the case, it is a bad idea.

dekindy

I have no actual experience, but from reading previous threads it is my understanding that the 705 model will not turn on with an external battery connected like the 305 does. Have you tested it?

DonFrambach

My Garmin 705 seems to run just fine with an external battery attached to it. If I attach the external battery with the Garmin turned off, it turns on. If I attach the external battery with the Garmin turned on, it continues to function. An icon does change indicating that the Garmin is running on external power. If I remove the extenal battery, I receive a message that the external battery has been removed and I'm ask to push "enter" but the Garmin continues to function.

I've mounted the external battery on my bike so I think I'm good to go for the double century this weekend.

The reason I wanted to use the Dinotte battery is that it is huge compared to the AA batteries so I assume it will last much longer. Additionally, the Dinotte battery is sealed and has attachments to easily mount it to my bike.

If anyone cares, I'll report back how it works this Saturday.

socalrider

Be careful using that battery pack with the Garmin, it does have certain power requirements, there were a bunch of threads on this very issue over a year ago..

If you want a smaller battery pack that will run that a long time, look at the apc mobile power pack, it uses both standard and mini usb connectors.

https://www.google.com/search?hl=&q=a...US369&ie=UTF-8

es82

What about something like the Duracell Instant Charger -- charges any USB-powered device. I'm doing a multi-day ride this summer and will probably be getting that/something similar for my 605.

DonFrambach

I purchased the Duracell Instant Charger and it works fine too. But it can't be "recharged" during the ride. I'm going to use another external battery that has two replaceable AA NiMH batteries so I can carry an extra pair on this upcoming ride. I don't think I'll need them but it's reassuring to know that I won't run out of batteries when I use a little back-lighting at night.

BTW the Duracell battery is very small and light (and has a convenient on-off switch) so it may be the best way to go once I figure out how much battery life I need. I think the Duracell battery will about double the Garmin battery life but I have yet to test that.