Solar charging for Bosch e-bike batteries

[The Cycle Tourist]

I have been looking for some time (without success) for a company (or an individual) capable of providing a solar charging system for Bosch batteries for a Haibike 700c xDuro trekking e-bike.

My wife and I are setting off on an extended self-contained e-bike tour of the UK, Europe and Scandinavia starting in late April and want to be freed from the daily need to hook into mains power.

We will be towing cycle trailers, so the plan - if we can find someone to work their solar magic - is to attach the solar panels to the top of one of the trailers.

Our Haibikes feature the Bosch performance crank drive motor and are powered by Bosch 400Wh PowerPack Batteries. All the so-called solar experts I have spoken to so far say its not possible to charge Bosch batteries with solar, but a couple of Germans completed a tour of Mongolia in 2012 on e-bikes with Bosch batteries and exactly the system I am after so I know it CAN be done. Unfortunately I have not been able to get in touch with the Germans and Bosch themselves have been of no help.

Surely there is someone out there with the expertise to do this, after all it isn't rocket science!

 

[Wicky]

View the website on Google Chrome and use translate to get german into English

http://www.tour-de-mongolia.com/fahrzeuge-und-technik/

"The long tiller that works wonderfully well with the 29 "wheel has proven to be a useful element in the construction of solar charging system that has evolved from Uwe Schlemender ecomo21. He brought a clutch on the tiller at about the semi-flexible solar panel can be swiveled in the respective best angle to the sun (90 °). Depending trailer two 1.1 m were long, 33 cm wide, weatherproof solar panels with 21 Wp combined power of a stabilizing rail and connected in parallel. At the bottom of a small universal charger is the company Sunload is fixed, which accommodates up to 50 watts and charges the Bosch battery in this configuration under ideal conditions with an average of about 40 watts. That is, in full sun and the best alignment of the panels, it takes 7 hours to get a 288 Wh battery is full. The charger had to be modified so that it can load the Bosch-Battery. ...

For our solution, we were lucky that we still could find two Sunload Universal chargers because they are no longer built. A similarly small and lightweight charger that connects the battery directly with solar panels, it does not yet exist."

Solar charging: You have a technical problem!

http://www.tour-de-mongolia.com/2012/06/19/solarladung-ihr-habt-ein-technisches-problem/

"The specifications were first to load the Bosch batteries over the original chargers with Schuko plug, since these are the only ones on the third Bosch-specific 5 volt pin for communication between battery and charger. That would be our charging system would consist of solar panels, intermediate battery, voltage transformer, Bosch charger and battery. What then were up by solar energy in the battery pack would make the whole thing to a laughable exercise. The only alternative: the Universal Travel Charger mVELO of Sunload, which has been designed to pedelec batteries to charge solar panels without the need for an intermediate battery and a voltage converter. Wonderful. But unfortunately no longer available. And now? The Tour de Sahara - since we had Sunload chargers here.

Four partly broken and partly functioning of mVELO miracle chargers we could find. But the next problem was immediate: it does not work with the Bosch-Battery. Again, there was a solution: John Dörndorfer of Europe engineering. He repaired and modified the chargers so that we can now use two mVelos load the Bosch batteries. We keep him, as our own eyeball!"

"Pro bike we have five batteries, each with 288 Wh power (36 V, 8 Ah) is available. A battery is 2.5 kilos relatively easy; in total there are at least 25 pounds! Each of these batteries to us over medium support, bring a lot of luggage and estimated on rough surfaces 50 kilometers - maybe more if we have eaten all our supplies! The manufacturer Bosch are ranges of between 40 and 105 kilometers, depending on the backup mode."

 

[flecc]

Noticing you are in Australia and that the tour you mention was in Mongolia, both are noted for their clear sunshine hours.

In the UK, Scandinavia and much of Europe the conditions are very different, often extended periods of all day dense cloud cover and even on the odd days of few or no clouds, our air in industrialised Europe is never remotely as clear.

The outcome is a huge reduction in potential solar panel outputs. I think you'd be very hard pushed to consistently every day recharge a 400Wh lithium battery from a reeasonable trailer area panel coverage, or to keep it topped up to full during daylight hours.

One of our most experienced magazines covering e-bikes had a fair sized Somerset panel installation on a shed roof which commonly took as much as three days to charge a 156 Wh NiMh battery for a Giant Lafree. The panels they were using would have to have a very large trailer for them to be fitted above and they never achieved that much smaller charge in one day to my knowledge.
.

 

[Deleted member 4366]

http://www.veloverde.net/batteries/chargers/solar-chargers/portable-solar-charger-for-24.html

You'd have to splice its output into the wires that run from your battery to the motor to bypass the battery charge control system, effectively charging the batttery through its output wires.

You can get step-up charge controllers that are a combined charge controller and dc/dc converter. If you can find one that adjusts to 42v, you could use it with any solar panel.

Like Flecc says, you won't be going far in the UK if you rely on salar charging. When the sun goes behind a cloud, you get nearly nothing from a salar panel.

 

[Deleted member 4366]

Something like this

http://www.aliexpress.com/store/product/MPPT-Boost-Solar-Charge-Controller-step-up-90V20A-charge-all-kinds-battery/515737_1708497647.html

 

[Gringo]

Totaly not what you wanted but would a £100 camping generator get the job done ?
http://www.generators-direct.co.uk/camping-and-caravan/clarke-g720-petrol-generator

 

[Deleted member 4366]

That one's too heavy, but you can get Chinese ones that only weigh 9kg. Tony from Woosh had some samples. The Kipor one is about 10kg