Charging electronics on the move

Gazjacko

Active Member
I have just acquired a new Tandem with a Shimano dynamo front hub (currently running the front light). Is there a way to use the generated power to charge my car satnav for navigation via a USB ?
 
What is the voltage of the front light? Do these set up have a buffer battery?
 

Vantage

Carbon fibre... LMAO!!!
Before you charge anything you'll need a converter. List here.
Before you buy one of those, look at the power output of your hub. You'll be needing 6v 3w for it to be any use.
You'll also be wanting a cache battery if one isn't included with your converter. Some devices don't take kindly to the stop/start nature of dyno hub charging.
You'll also need to be in reasonable shape. Typically, you'll need to riding at 10mph ish for the hub to generate enough power to charge.
You'll also need to note the power requirements of your car satnav.

On my last tour, I used a B&M Ewerk with cache battery to charge my phone. Running on standby and starting from 100%, my phone was down to 86% after a 7 hour ride.
Other folk may have had better results as I don't know the original condition of the battery (it was given to me) but on that experience I wouldn't expect miracles from dyno hub charging.
Another option open to you is to just use a portable battery. There's plenty out there.
 
My setup is Son Dynamo -> B&M Ewerks -> B&M cache battery ->Garmin Etrex 30 Sat Nav.
It happily powers the Garmin above about 3.5-4.0 mph with the lights off, ~2 mph faster with the lights on.
The cache battery is there for when I climb hills slowly on my bent trike and to stop the Garmin switching off if I stop for longer than a minute at a road junction.
The AA's in the Garmin lasted for around 3 months while on tour before I had to recharge them.
It all depends on the cache battery if that type setup is possible.
If the battery lets you do pass through charging, you can charge a device from the battery while at the same time charging the battery from a power source, then the above setup works fine.
If not the other option is to carry two cache batteries.
Charge one battery from the dynamo via a converter while the other battery is used to power the sat nav.

Luck .......... :biggrin:
 

Randomnerd

Formerly known as Woodenspoons
Location
North Yorkshire
SINEWAVE

No affiliation. I’ve used it trouble-free for a few years.

It’s quite expensive but the benefits are that it is very sturdy and unobtrusive.

I run a phoneFrom it to keep charged for emergencies all day and often come Back from a ride with the battery full. Good for when you’re away and want to top up an iPad or other device. Would be powerful enough to split and run two gizmos i expect if you had to.:okay:
 
OP
Gazjacko

Gazjacko

Active Member
What is the voltage of the front light? Do these set up have a buffer battery?
I don’t know, I will have a look, but assuming it’s 6v and no battery back up. I’ll also have a look down the back of the sofa for spare coin because I’m shocked at the cost!
 
Last edited:
I have just acquired a new Tandem with a Shimano dynamo front hub (currently running the front light). Is there a way to use the generated power to charge my car satnav for navigation via a USB ?
I'd query the suitability of using a car satnav to navigate a bike!
Apart from routing, a bigger screen, colour maps, voice prompts all add to the power usage significantly.
What about inclement weather?
Then, there's mounting it (securely) to the bike!

After that, as others have said, you will need a converter between hub and gps.

A battery is a very good idea too (I charge a gps or a powerbank from my hub - nothing else). The problem is you will need a "pass through" powerbank for that - not cheap.

Simplest thing to do is use a "normal" powerbank to power the satnav (easily tested at home). A second powerbank from the hub gives spare capacity.
I'm not sure how the latest "smart" powerbanks interact with intermittent charging.

However, check wattage of hub or all this is moot.

A cheaper and definitely workable solution is to use your phone. Osmand is a clunky but good app. Pair it with cycle.travel to plan a route.

If you do give it a go with the Satnav please come back and update us! I'd love to know!
 
I don’t know, I will have a look, but assuming it’s 6v and no battery back up. I’ll also have a look down the back of the sofa for spare coin because I’m shocked at the cost!
If it we’re 12v I’d give one of these a go:

https://www.ebay.co.uk/itm/Waterpro...-/274465403202?_trksid=p2349624.m46890.l49292
 

contadino

Über Member
Location
Chesterfield
What Hobbes said. I use an old phone with no SIM running Osmand for nav. With the screen on all day it'll use 60% of a charge. I have a powerbank with 4 recharges that weighs maybe 150g, and I rarely spend more than 6 days in the wild nowadays.
 
Another option I've done is to use a AA battery powered sat nav like an Etrex 30 as a set lasts around 2 days of use on tour.
Then just use an USB powered AA battery charger via a converter from the hub to keep a spare set of batteries charged.
With no wires into the back of the satnav, I found that a very robust setup when it rained a lot on tour.
If the battery charger can work backwards as a power source then you can keep a kindle charged as well.
But I don't know about keeping a modern phone charged with that setup as I've never tried that.
Plus you can always carry a pair of Duracell's for emergency use.

Luck ............. ^_^
 
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