# Electric bike charging



## charlieivan

My wife has an electric bike that we take with us in the motorhome. When staying on sites or anywhere with ehu there is not a problem with charging the batteries. We would like to go to some rallies or other places without ehu but how can we charge the bike battery? An inverter would probably make too big of a drain on the leisure battery so how do others cope?


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## Drew

When we bought our first "real motorhome" in 1993, the first accessory I bought was a Kawasaki generator. At that time it was one of the smallest on the market at 360 watts. It was the best investment ever having served us now for 26 years.

Although I changed our van on two occasions I have used it to this day, not on a van any more but in the garden and also when we have had a power cut. We always used it carefully so as not to annoy others and have asked our neighbours permission when on THS or on a rally.

I would suggest that you invest in a small generator with just enough output to recharge your batteries and run your fridge, lighting etc.


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## peribro

Would it be that big a drain? Bike batteries are generally around 10ah to 15ah I thought so if it was discharged down to say 25% remaining you'd only be putting in between 7ah 12ah. Add a little bit for inverter inefficiency and it's still not much of a drain. How many leisure batteries do you have? If you've got a couple and a solar panel then I would have thought you'd be OK - dependent obviously on the sun shining and what else you use through the batteries.


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## EJB

I've just changed MHs and a 100w solar panel and inverter have solved that problem. It obviously keeps both vehicle and leisure batteries charged at all other times as well!


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## Penquin

We maintain our electric bike using a small inverter and the solar panels - by charging during the day it helps ensure the the leisure batteries are not discharged at all. 

We have a Honda generator (1kw) and have used it twice in 14 years..... It has not earned it's place really but is there "just in case".


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## barryd

If it can be charged using an invertor and solar panels my advice would be charge the hell out of everything in the morning thus leaving time for the batteries to get back up to fully charged in the afternoon. I find that they are quickly charged from this time of year right through the summer so the MPPT controller cuts off and stops charging by mid morning. There is no logic or maths behind this, its just what I have observed.


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## nicholsong

For my education, what voltage are the bateries and the motor on these e-bikes? Are they 12v?



I understand that the normal charger usees mains 230v but is that being stepped down before the batteries, like a mobile phone charger to 19v.


If this is the case cannot charging somehow be done in a MH without the inefficiency of using an Inverter to get to 230v and then the charger to drop back down?


Just asking.


Geoff


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## Penquin

The battery voltage is often 36v so while it MIGHT be possible to find a 12 to 36v connection it would still be inefficient and effectively drain the lb.

e.g. This American made system

https://www.powerstream.com/dc36.htm

But 177$ plus delivery and taxes....... ????????

Ouch:nerd:

Although this would be much cheaper.....

https://www.ebay.com/itm/Car-DC-DC-...268670?hash=item1c87d997fe:g:eUYAAOSw7tRbDPGc

Using a universal low amperage inverter works and it charges quicker than it would using such a connection as I suggested above, because the inverter is delivering 230v.


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## nicholsong

Penquin said:


> The battery voltage is often 36v so while it MIGHT be possible to find a 12 to 36v connection it would still be inefficient and effectively drain the lb.
> 
> e.g. This American made system
> 
> https://www.powerstream.com/dc36.htm
> 
> But 177$ plus delivery and taxes....... ????????
> 
> Ouch:nerd:
> 
> Although this would be much cheaper.....
> 
> https://www.ebay.com/itm/Car-DC-DC-...268670?hash=item1c87d997fe:g:eUYAAOSw7tRbDPGc
> 
> Using a universal low amperage inverter works and it charges quicker than it would using such a connection as I suggested above, because the inverter is delivering 230v.


Dave

Thanks. Now that I know the system is 36v I can understand the problem - different from going from 12v to 19v for my laptop.

I had always ruled out e-bikes for our off-grid camping and it still looks problematical.

Geoff


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## Penquin

If you a solar panel system it is not a problem at all, a flat bike battery takes about 2 - 3 hours to charge on an inverter, or the mains, so two bikes can be done within a day and most solar panels continue to deliver >1.0a even without full sun.

The important thing is to ensure that the vehicle's leisure battery system remains capable of supplying sufficient power for the MH use - and the item with the heaviest drain is probably the TV as it tends to be on for hours.....


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## charlieivan

Thanks all for your comments.. If I wanted to try charging with an inverter, what type and size would you recommend? If I found the inverter to be a success then the next step would be to have a solar panel fitted. Again what type and size would be ample as it would mainly be used for the bike battery charging and keeping van batteries topped up as a bonus?


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## barryd

charlieivan said:


> Thanks all for your comments.. If I wanted to try charging with an inverter, what type and size would you recommend? If I found the inverter to be a success then the next step would be to have a solar panel fitted. Again what type and size would be ample as it would mainly be used for the bike battery charging and keeping van batteries topped up as a bonus?


If your going to be going off grid then a solar panel is vital anyway. Its one of the best things I ever invested in and not expensive either. What size or how many panels is a difficult one to answer though. I just have one single 100 watt (might be 120 I Cant remember) and a single 125ah battery but our van is low usuage on power. Heating does not use any power, gas fridge, LED lights (not all but most), 1.2 amp TV. Its more than enough for us and this time of year I can stay in one place for weeks and not worry about power. I run laptops and music stuff for hours on end as well.

If you have two batteries you may be better going for two panels though. I think the rule of thumb is match your battery power to your panels and get a good MPPT controller. Regardless of the bikes you will never look back getting solar.


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## nicholsong

Penquin said:


> If you a solar panel system it is not a problem at all, a flat bike battery takes about 2 - 3 hours to charge on an inverter, or the mains, so two bikes can be done within a day and most solar panels continue to deliver >1.0a even without full sun.
> 
> The important thing is to ensure that the vehicle's leisure battery system remains capable of supplying sufficient power for the MH use - and the item with the heaviest drain is probably the *TV as it tends to be on for hours...*..


Our TV has *NOT* been on at all for the last 8 years - since I teamed up with Basia.


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## Mrplodd

We often charged our two electric bike batteries via an inverter (cheap one not a fancy pure sine wave Jobbie) when we had a MH without problem. 2 x 115 AH LB’s and 100W solar panel. 

Don’t forget you can still use the inverter whilst driving!! We often used put a meal on to cook in a 230v slow cooker whilst driving during the day (slow cooker in sink before anyone asks) and it worked really well. 

Andy


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## barryd

nicholsong said:


> Our TV has *NOT* been on at all for the last 8 years - since I teamed up with Basia.


What do you do all evening. :shock:


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## JanHank

barryd said:


> What do you do all evening. :shock:


Our TV has never been on except to try it at home and it picked up Polish TV 📺 😕 .


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## barryd

"You people" are odd. Must be being all foreign or summat. 8-[


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## raynipper

JanHank said:


> Our TV has never been on except to try it at home and it picked up Polish TV 📺 😕 .


Yes Jan. I think if I could only get Polish TV I would keep it turned off.
Luckily we get 24 freeview and 200 freesat channels all in English (apart from the Americans) to chose from.
Thats before going online which is crap but necessary when in Portugal.

Ray.


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## nicholsong

raynipper said:


> Yes Jan.* I think if I could only get Polish TV I* would keep it turned off.
> Luckily we get 24 freeview and 200 freesat channels all in English (apart from the Americans) to chose from.
> Thats before going online which is crap but necessary when in Portugal.
> 
> Ray.


'penquin' was referring to MH TV.

In the MH we have left Poland within 1 day. But even in France or UK it has not been turned on. But we have only been together 8 years:wink2:

As for Barry's Q - we eat, talk, play backgammon etc. Is Michelle allowed in the office/studio?

Geoff


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## JanHank

nicholsong said:


> 'penquin' was referring to MH TV.
> 
> In the MH we have left Poland within 1 day. But even in France or UK it has not been turned on. But we have only been together 8 years:wink2:
> 
> As for Barry's Q - we eat, talk, play backgammon etc. Is Michelle allowed in the office/studio?
> 
> Geoff


I was also referring to the MH Geoff, I think Raymond got the wrong end of the stick because I said I had only tried it at home.
We have been together now for 42 years and we still don't need TV to entertain us in the motorhome or at home mostly. :grin2:


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## Drew

I thought this thread was about charging a battery? This is getting as bad as "Owners".


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## JanHank

Drew said:


> I thought this thread was about charging a battery? This is getting as bad as "Owners".


I _think _the question has been answered Drew, you know how it is, one thing leads to another.



charlieivan said:


> My wife has an electric bike that we take with us in the motorhome. When staying on sites or anywhere with ehu there is not a problem with charging the batteries. We would like to go to some rallies or other places without ehu but how can we charge the bike battery? An inverter would probably make too big of a drain on the leisure battery so how do others cope?


Has your question been answered Charlieivan?


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## Penquin

Drew said:


> I thought this thread was about charging a battery? This is getting as bad as "Owners".


Why ?

Because people like to try to help ?

Because others may have different points of information that is useful ?

Such as Nicholson now knows the voltage that many electric bikes use, although not all, I believe 36v is the highest in use currently due to EU Regs.

Why should people not be friendly towards each other ?

This forum has always been a friendly, informative forum and after all Facts was the first and was the model for Fun which only started after a fallout between Jim and Nuke.

Long may it have that reputation IMO.

Hence why I have tried to justify my response to your statement, rather than an abrupt answer that might be found elsewhere.


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## barryd

nicholsong said:


> 'penquin' was referring to MH TV.
> 
> In the MH we have left Poland within 1 day. But even in France or UK it has not been turned on. But we have only been together 8 years:wink2:
> 
> As for Barry's Q - we eat, talk, play backgammon etc. *Is Michelle allowed in the office/studio?
> *
> 
> Geoff


No! Ive tried to ban her but she takes no bloody notice.


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## Drew

The OP asked for our opinion on charging a battery on an electric bike, not on whither we watch TV to not.

Electric bikes are supplied with a charger for the use off, i.e. with an input of 220v and an output voltage capable of charging the battery. No matter what the output voltage is it requires to be plugged into a normal 13A socket. Where this mains voltage comes from is immaterial, I suggested a small generator, easy to use and will supply 220v no matter what the conditions. Solar panels require require decent weather to charge batteries and are costly to fit. An inverter must also be added, that alone can knacker any battery in a short time.

Cost wise if you haven't already got solar panels fitted favours a small generator.


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## barryd

Solar isnt costly. I think my kit was about £200 and £90 for my fixit bloke to fit it. How much is a decent genny like a Honda? Double that I bet.

A decent solar system through spring summer and autumn should give you enough power. Winter you want to be on hookup really anyway most of the time.


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## charlieivan

JanHank said:


> I _think _the question has been answered Drew, you know how it is, one thing leads to another.
> 
> Has your question been answered Charlieivan?


Yes thank you. Enjoy the rest of the banter !!!!


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## Penquin

Off topic true but relevant (possibly),

Our 1.0 kw Honda genie, s/h off eBay UK cost £525 in order to charge the bike battery off EHU It takes around 2- 3h from flat.

Using the solar panels, and a small inverter it takes around 2 - 3h from flat.

The gennie purrs and is not noisy but is audible, for that number of hours it probably uses about 0.05litre petrol (not converted it to run off gas as we also use it to power things in the garden well away from the MH. Current petrol prices means that would be around 7€cents. It also, of course, needs regular servicing, even if not used and we must carry a 5l can of very flammable petrol.

The solar panels cost less than £160 fitted (2 x 80 watt), they are silent in use and require only brightish daylight to function, so no fuel costs and no noise at all. They require cleaning, when I clean the MH, perhaps every few weeks, and that's it, no other servicing at all.

To me it is a no-brainer, the solar panels win every time, even if it is cloudy, all that MIGHT happen is that the leisure batteries MIGHT diminish from 100% charged to 99% charged which will NOT affect operation.

That's my (hopefully) logical view of things. Others may well come to a different conclusion, such as it is hard to transfer solar panels to another vehicle, easy to transfer a gennie plus fuel.


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## barryd

My advice would be to get Solar anyway as its a no brainer and see how you get on. For what they cost they are worth having anyway. you could always look into a Genny later especially if you go off grid in winter but lets face it. Its no fun wilding and worrying about power when its dark at 4pm. Find a hookup.

As for the banter, its a good thing as its fun and it also pushes the thread back to the top so someone who hasnt seen it might come back with a new answer.


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## JanHank

Perzackly.


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