Tom and I were chatting about the kit that we took on the divide today.

One thing that we did recall was that the Zendure batteries we took along did something unexpected.

If unconnected to the Cinq Plugs (dynamo) they would happily run our Garmin Oregons without turning off.

However if we tried to thru charge, ie the battery plugged into the Cinq plug and the Oregon plugged into the battery then unless the battery was being charged the Zendure battery would turn off.

Does this happen on other batteries that supposedly thru charge?

My USB battery pack does not turn off but i amusing it to run the light not a GPS- sinewave beacon light not sure how long i have stood still to see what happens so I guess it might if i wat long enough but certainly done 10 mins yapping , How soon dies it switch off ? Instantly ?
I have an Etrex 30 but never used it so might experiment tomorrow to see if can what with all this free time i have
NOt that useful I am afraid but i cannot see why you would want the battery to swicth off in that way s seems odd to design it that way

Doesn't on mine Rich. It's pretty old though and was just an unbranded "7 day shop power bank".

I never had great success with thri-charging on my Zendure Rich.

I've not tried through charging with mine but interesting that it would power your Oregons. When I tried to use mine to power an Etrex 30 it would turn off as the Etrex draws less power than the minimum for the Zendure to stay on.

My understanding is that the Zendure has a circuit to detect the current draw and if below a certain level it assumes the device it's charging is fully charged or it's a short in an unplugged cable and switches off. So either the set point on mine is too low or the Oregon draws more power than the Etrex.

Can I ask which model of Oregon and what size Zendure you have?

Current draw would have been my guess as well.

My Oregon 600 with screen on (default when drawing power from an external source) is 50mA or thereabouts. Turn the screen off and that drops to around 30mA. Garmin assume that an external power source is something like a car or boat battery so ignore your power saving settings which is why you have to turn off the screen.

However, what Rich describes isn't quite like that. I suspect there's some further logic inside the Zendure about when to enable power out. Rich - does simply plugging the Cinq Five into the Zendure cut power to the Garmin or does this only happen if you've been moving and therefore charging the Zendure then stop? They are different use cases.

Thanks all for the replies.

Yep in order to make the battery not turn off, I'd leave the backlight on for a couple of pips otherwise as you say , the battery would auto-off. (Oregon 600 and 300 the same)

The garmin would be happily drawing from the battery, though plug the battery into the dynamo and the garrmin claims it's lost power.


Has anyone used Mophie batteries?

So simply plugging the battery into the Cinq causes the Garmin to lose power? That's whilst the bike is stood still so the dynamo/Cinq isn't putting out any current?

While pass-through sounds like a good idea, information from the likes of Anker suggest that it's difficult to implement in a way that doesn't drastically reduce the lifespan of the battery cells.

I just charge the battery by day and then use it to recharge Garmin, phone, light at night when I'm not moving. Take 2 x 10,000mAh batteries rather than a single 20,000mAh one: you can charge one while using the other; you've also got a backup in case one gets damaged.

So simply plugging the battery into the Cinq causes the Garmin to lose power? That's whilst the bike is stood still so the dynamo/Cinq isn't putting out any current?

No, the cinq would have to be giving current, though not enough to be charging the battery at full gas.

I just charge the battery by day and then use it to recharge Garmin, phone, light at night when I'm not moving. Take 2 x 10,000mAh batteries rather than a single 20,000mAh one: you can charge one while using the other; you've also got a backup in case one gets damaged.

Thankfully we did go with the boot and braces approach, so yes we had two batteries each. Charge one, use one.