Running a Garmin off a dynamo!

[HUX]

So I have an Etrex 20, a SON hub and a alpkit juice hub, a Nitecore F2 18650 charger and a k-lite usb charger. Is there a knack for running the Etrex directly from the hub without it wanting to revert to the aa power source. The Nitecore charger supposedly allows pass through charging so I figured that might work, it does for a while then wants to switch to AA. K -lite Kerry mentions some sort of usb buffer whatever that is. Any ideas?

[Bearbonesnorm]

Did you read what Kerry wrote about pass-through batteries / charging Hux?

what is pass thru??.... what people think it is... is not what it actually is,let me explain...

What people think it means is DUAL USE>...'dual use' means....getting charged and being used at same time ... like a UPS on a computer. It keeps device / GPS going no matter of which power input you use.

NOW what pass thru actually means is ... passing input power directly to OUTPUT and NOT charging battery first ... then draining it right away ... as you can loose up to 20% in chem reaction to charge a USB cache battery...so pass thru, avoids this loss and a battery is much happier when it's very low ... as it just gets bypassed to device .. when battery is very low, it labours when asked to provide current to device, this can damage battery and another reason for pass thru. Pass thru capability is hard to test for....and often impossible to know if it's included on your USB cache battery

On paper it does look better to charge phone directly from dynamo powered USB charger ... this avoids the up to 20% losses when charging. HOWEVER, in the real world...
socket damage due to rough roads is better done on a cheap USB cache battery rather than a $1200 iphone.

A lot phones won't sit in FULL power saving mode when on the charger, and any fancy electronics are better hidden behind the electronics of a USB cache battery...so its better to charge a USB cache battery....then phone at night when stopped for all the reasons above.

People think pass thru is DUAL USE>>...pass thru is actually power shunting direct to device, so testing for dual use will NOT prove pass thru is there or present. as they are actually different things.

Double charging is to be avoided, if possible....as is direct charging from dynamo powered USB charger. as is using the socket in your fancy phone while moving.

Happy new year...hope this helps.

[Mike]

mate ive gave up on that! Just going to use a battery pack to charge in the day and use that for a power source at night when i cant find a 240v plug.....not so sold on this on the move charging either if im honest, unless your on roads all day and moving at a constent then i think its a bit of a waste of time especially off road??

the light side of it is ace though

[lune ranger]

I'm a big fan of off grid power for bikepacking and charge various devices at different times from my dyno via an Igaro. I don't bother with my etrex though.
AA batteries are pretty small and rechargeables can power an etrex for a long time. One spare set with fresh ones in the unit at the start of a trip will give multiple days of navigation. If disposables are your thing then AA's are available just about anywhere there's shop in the U.K. or abroad.
On long term tours I've used a USB battery charger to charge AA's either from dyno or the mains as available and carried 3 sets for the etrex.

[SeannyD]

I use one of these (without solar) and carry a couple of spare charged AA’s works for me,
https://www.goalzero.com/shop/recharger ... ower-bank/
Good for short trips and gives choice of batteries (AA and AAA) or usb use.

[Lazarus]

another for just using rechargeable AA batteries - i have small two battery aa usb charger [ weighs next to nothing] and can charge batteries if i get desperate . I have not needed to yet carrying only two sets [ my screen is set to off when its on to reduce power usage but it comes on if you touch the screen