# X35 ebikemotion range extender



## G3CWI (12 Mar 2020)

Just received a range extender for my Orbea - ready for some longer runs in the summer. It's an odd beast. It does not look like a water bottle and is a bit clunky to use. It's not simply another battery but rather it works as a charger for the main battery. That sounds less efficient to me. It also seems to go against ebikemotion's own advice in that it charges the internal battery to 100% and I assume that it will run itself down to zero (safety low-voltage cut out I hope).

My bike has a small frame and that means that with the range extender installed, my normal bottle does not fit in properly as it hits the range extender. It has a rubber strap but the cage is poorly designed for the strap to attach. Apart from that it seems to work. Did I mention how incredibly expensive it is? Score 5/10.


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## aldus (12 Mar 2020)

Wow!  Just saw the price on that unit... I could buy a non-discounted second battery from Bosch for that!


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## G3CWI (12 Mar 2020)

aldus said:


> Wow!  Just saw the price on that unit... I could buy a non-discounted second battery from Bosch for that!



You could buy a half decent bike for that!


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## youngoldbloke (13 Mar 2020)

Odd that Orbea (and others) go to a lot of trouble to make their e-road bikes look like 'normal' bikes, then produce an add-on battery that looks so awful. The cage isn't very attractive either.


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## Scaleyback (13 Mar 2020)

I'm guessing they are not going to sell many ? economies of scale will keep the price high.


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## Pale Rider (13 Mar 2020)

G3CWI said:


> It's not simply another battery but rather it works as a charger for the main battery



At first blush that does seem an odd electrical engineering solution.

However, the Gain's integrated battery means there's not any other practical way to attach a 'spare' battery.

Those of us with ebikes with detachable batteries can simply change to a fully charged one when the first goes flat.

The twin battery installation on my Riese and Muller ebike is quite clever.

It has different wiring loom and software which sips from each battery alternately until both are flat.

The system charges in the same way.


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## G3CWI (13 Mar 2020)

Pale Rider said:


> At first blush that does seem an odd electrical engineering solution.



I rather doubt that you actually get the full benefit of the stated capacity. I also note that the extender charges the main battery a lot slower than the main battery discharges - and on a more challenging ride that could be an issue. It seems like a bodge to me.


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## Pale Rider (13 Mar 2020)

G3CWI said:


> I rather doubt that you actually get the full benefit of the stated capacity. I also note that the extender charges the main battery a lot slower than the main battery discharges - and on a more challenging ride that could be an issue. It seems like a bodge to me.



I suspect that's right, apart from anything else there's always losses when you shunt electricity from one storage medium to another.


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## youngoldbloke (4 Sep 2021)

Is there any reason the X35 range extender couldn't be shared with a second bike? eg - used with one bike on one ride, then charged and attached to a second bike for another ride.

edit: - to avoid confusion - both bikes using the X35 system of course.


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## Biker man (4 Sep 2021)

Pale Rider said:


> At first blush that does seem an odd electrical engineering solution.
> 
> However, the Gain's integrated battery means there's not any other practical way to attach a 'spare' battery.
> 
> ...


That is brilliant I was wondering how it works thanks .


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## Biker man (4 Sep 2021)

G3CWI said:


> Just received a range extender for my Orbea - ready for some longer runs in the summer. It's an odd beast. It does not look like a water bottle and is a bit clunky to use. It's not simply another battery but rather it works as a charger for the main battery. That sounds less efficient to me. It also seems to go against ebikemotion's own advice in that it charges the internal battery to 100% and I assume that it will run itself down to zero (safety low-voltage cut out I hope).
> 
> My bike has a small frame and that means that with the range extender installed, my normal bottle does not fit in properly as it hits the range extender. It has a rubber strap but the cage is poorly designed for the strap to attach. Apart from that it seems to work. Did I mention how incredibly expensive it is? Score 5/10.


How many miles do you think you could do now.


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## CXRAndy (4 Sep 2021)

youngoldbloke said:


> Is there any reason the X35 range extender couldn't be shared with a second bike? eg - used with one bike on one ride, then charged and attached to a second bike for another ride.
> 
> edit: - to avoid confusion - both bikes using the X35 system of course.



The ebike website says the extender comes with a quicklock release mechanism.

As long as the both bikes are equipped with the necessary connection point, then I can't see a problem.

The answer to the question, is do all x35 have the connection installed?


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## youngoldbloke (5 Sep 2021)

I was wondering if the software was set up so that once connected to a particular bike the extender would be linked electronically to that bike specifically.


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## CXRAndy (5 Sep 2021)

youngoldbloke said:


> I was wondering if the software was set up so that once connected to a particular bike the extender would be linked electronically to that bike specifically.


I wouldn't be so surprised if they did have some sort of handshake verification with each battery pack. 

It would be just like Bosch


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## gzoom (5 Sep 2021)

G3CWI said:


> I rather doubt that you actually get the full benefit of the stated capacity. I also note that the extender charges the main battery a lot slower than the main battery discharges - and on a more challenging ride that could be an issue. It seems like a bodge to me.



That sounds like a pretty awful setup, I presume if you were actually pushing the main hard with usage the range extender charging rate wouldn't be able to keep up?

Battery setups can get complicated especially with trying to add additional capacity, which is why I suspect the X35 system has gone for essentially a USB recharging battery pack approach rather than a proper shared/parallel additional battery setup.

You will 100% 'loss' power by recharging a the main battery from the range extender versus driving the motor direct, DC to DC energy loss are going to be at least 10%+, so right from the start the actual usable capacity of the range extender will be 10% less than advertised. You than need to add in batter to motor losses which will be around another 10%, so if the range extender is 250wh advertised you will be looking at around 200wh actual usable. You will also loss the first 5% of usable battery quite quickly in initial degredation.

Am not sure how much the range extender is, but if it costs £300, than you are essentially paying £1500 per usable kWh!!! For reference an EV traction battery 78kWh usable (85kWh gross) will cost you around £250 per kWh, installed in a car. So eBike batteries are crazy expensive compared to car batteries!!!


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## sasquath (5 Sep 2021)

You will loose up to 5% on charging process alone, there are regulator losses of at least 10%.
To use direct connection you would need motor driver with 2 separate inputs. Or both batteries would have to be at exact same state of charge at the moment of connection. Connecting full and empty, or even half full batteries in parallel could end in 🔥. Battery damage at best.


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## youngoldbloke (13 Jan 2022)

After trying in vain to order a Volabike extender for my Gain I have now purchased a Mahle (EBM) X35 extender. Ugly and heavy but it works well!
A question for others using these: 
Do you try to look after them in the same way as the main battery - eg try to store charged between 30% and 80%? 
(I try to leave my Gain's battery at 70% - 80% if not riding it for a few days, and only charge to full if I know the ride may need it)


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## CXRAndy (13 Jan 2022)

youngoldbloke said:


> Do you try to look after them in the same way as the main battery - eg try to store charged between 30% and 80%?


Yes, treat it just like the main battery for most occasions. Keep indoors in winter to prevent frost damage


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## Specialeyes (13 Jan 2022)

To answer an earlier question, they're not tied by software to a particular bike in a multi-Mahle household, but you do need to switch the 'bottle cage' across too.


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## youngoldbloke (13 Jan 2022)

Specialeyes said:


> To answer an earlier question, they're not tied by software to a particular bike in a multi-Mahle household, but you do need to switch the 'bottle cage' across too.


That's good. and I thought you would have to swap the holder, the extender is a pretty hefty piece of kit. I couldn't find anywhere online that sells the 'bottle cage' separately. Not that I need another cage at the moment but I was considering buying a Ribble SLe - given Ribble's estimated delivery dates (September 2022 if ordered now) I'm not in a hurry! I think I'll stick with the Gain for now.


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