E Bike Charging From Your Vanagon

[Love My Westy]

Has anyone set up their Vanagon to be able to charge their E Bikes? In the future, more and more people will own E Bikes and charging them while camping will be necessary. I'm looking for pointers.

[shagginwagon83]

I'm sure people are doing this. You need to look at the output specs on the charger. I looked it up and a trek bike has like a 13aH battery. Using an inverter would work but it may be more efficient if you can rig up your own transformer (once you know specs).

Solar might be keep up, but alternator charging would be the best.
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Brandon
"Jo Ann" - '83.5 Westfalia EJ22e w/Peloquin
Instagram @joannthevan

[vwhammer]

If you are just trying to charge from the standard car charging system it should be pretty straight forward as long as the vehicle is running.
The only issue here is that my bike takes about 3 hours to charge the 10 amp hour battery so you would have to be driving around for 3 hours.

You would likely kill your battery if you tried to charge the bike with the vehicle off.

If you are going to be driving for some time then a small inverter (300-500 watts) could be hard wired to the battery with a properly sized fuse.
The fuse size would depend on your bikes charger.
Is it 24v, 36v, 48v or higher?
Is it a 3 amp or 5 amp charger?
A 20-25 amp fuse would cover the high current chargers and 15 a amp fuse would cover the lower current.

You could then plug in your bike charger and be on your way, charging while you drive.

If you have a house battery then this is as easy as hooking up a small inverter and plugging your bikes charger in.
Assuming you have a decent size deep cycle battery it should work fine.

[dobryan]

Look for a 12v charger for your bike. If one exists it is better than going thru an inverter.
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Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

MD>Canada>AK>WA>OR>CA>AZ>UT>WY>SD
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https://www.thesamba.com/vw/forum/viewtopic.php?t=695371

The Western Syncro build
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[vwhammer]

They do exist but are not cheap.

[pdm777]

I'm looking for the same solution.
14Ah electric bike battery.
I need a solution that can charge at night, 4-6 hours.

- An inverter will be less efficient than a DC charger?
- Will a (100+Ah) deep cycle battery give me a few charges?
- How do I calculate the number of charges with a 50Ah vs 100Ah battery?

Here's the charger specs:

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1990 Westy Full Camper

[vwhammer]

Well there are real generic ways to get in the ball park with all the numbers you are looking for.

So we know a standard car battery is 12.6 volts
Lets look at a 100 amp hour deep cycle battery
I like to convert all of this to watts or more importantly watt hours.

To do this we simply multiply the voltage by the amp hour rating.
I this case we get 1260 watt hours (12.6 x 100)

Of course we can not use 100% of those watt hours because lead acid batteries can not be discharged that far.
I mentioned in another thread that some deep cycle batteries claim that they can be discharged 80%.
This may actually be true with some batteries but you significantly shorten the lifespan of the battery by doing so.
Generally you only want to discharge them about 50%

With that said we now only have about 630 watt hours to play with.

Now what?

Well, looking at your charger it states that it is 54.6 volts and charges at 2 amps.
If we multiply the volts again buy the current, this time just amps not amp hours, we get about 109 watts.

So now lets look at your bike battery.
I am assuming based on your charger that you have a 48 volt ebike.

Generally a 48 volt lithium bike battery will have a max charge of a little over 54 volts.

We now know your voltage and you stated that you have 14 amp hour battery so now guess what we do.

we multiply the voltage by the amp hours again and get about 756 watt hours.
Of course generally you will not use all 100% of that capacity, more like 80%.
This gives you 605 watt hours

OK
let's put all of our ducks in a row.
House battery = 1260 watt hours of which we should only use about 50% which is 630 watt hours
So
House battery = 630 watt hours
Bike battery = 605 watt hours
Charger power = 109 watts

Lets now assume you rode your bike and used all of that 605 watt hours.

If we take that 605 watt hours and divide my the 109 watts that your charger can put out you should be able to see that it would take nearly 6 hours to charge it back to 100%.

You may also notice that your house battery only has 630 watt hours available to fill up a 605 watt hour battery.
This means realistically you would get one charge of your ebike battery from your house battery before the house battery would need charged back up.

This is not great and practically would only really work with a substantial amount of solar or running an alternator to charge the system.

Well I don't know if that cleared anything up but that's about as simple as I can make it.
I should also point out that this is best case scenario with zero losses due to inefficiencies from any conversions.
They numbers in the real world would not be that good.

[pdm777]

vwhammer:
thank you for clarifying.

I don't want to resort to running a generator/alternator.
Sounds like I would need a very large battery, how about
a used automotive battery (Prius/Leaf/Volt).

Goal is max Ah/cost.

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1990 Westy Full Camper

[rmcd]

I recall that different battery types (flooded lead acid, AGM, lithium ion) require different charging profiles. Could your alternator (or solar controller or inverter or ...) really produce the correct number of volts over the correct amount of time while compensating for the battery’s charge state and temperature? I’m sure there are many other characteristics to consider but I’m also just learning.

I would expect that the bikes battery manufacturers would spec these requirements and you could build or buy an appropriate charger? Using this as a starting point maybe will help you back into an appropriate method?

Listening intently to this an anything todo with Nissan Leaf batteries! Thanks for experimenting.
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VW LT40 build. Like a Vanagon but 30% larger in every direction and 40% slower even in metric.
https://www.thesamba.com/vw/forum/viewtopic.php?t=749359&highlight=

[vwhammer]

You are correct.
Lithium, especially, prefers a specific charge profile and as such makes it more difficult to charge from a vehicles alternator.
There are several ways to do this but none of them are fool proof or super simple and more importantly all that cheap.

I will say however that most of the generic ebike battery chargers on the market hardly follow any of these profiles.
You will know the chargers that do by the fact that they will be 5 to 7 times more expensive than the regular old black boxes that you get with your ebike or buy on the net.

All of this is what makes lithium much more difficult for the average user and also why some of this is just starting to catch on.
You really have to do your homework to make sure what you put together does not spontaneously combust.

It's funny that someone would mention Nissan leaf batteries because I just bought a pair of modules for use to power a portable diesel heater that I am going to use to heat my Vanagons, my 4 runner and my tent, heck I might even use it to heat my hammock. (though not all at the same time).

I am also trying to find a decent source to buy several more so I can build an electric motorcycle and a 24 volt 250 amp hour house battery for my main Vanagon.

Anyway I just sorted out (well I hope) the charging system that I will be using on my heater battery today but it is all ebay cheapo stuff so I can not vouch for any of it at this time.
It is also not going to be charged from a vehicle alternator so what I have does not really matter.

Either way I am not an electrical engineer so there is surely some things that I overlook from time to time.
Do not take any of my advice as the simple truth or the way.

My background is mechanical engineering and I have to do my own homework and consult with the EEs that I work with to really sort out all of this.

Electronics can be complicated.

As far as charging lithium from an alternator, this may give you some idea of the possibilities as well as the complexities involved.
https://shop.pkys.com/Alternator-Lithium-Battery.html

EDIT: ebikes and the ebike forums like endless-sphere.com are a good place to start in order to understand a lot of this.

And for fun here is my 2wd ebike that I have been ripping up on for the last 3 years or so.

It has pretty much changed once a year since I build it.
Stage one - Just the basics

Stage two - Commuter duty

Stage three - Off road mode.

Usually off road mode does not have the rack on the back but I was doing another thing so I put it on for a minute and have not taken it off.
Also pay no attention to the flat tire.
Life's hard.

[pdm777]

With all the 110V plug in microprocessor-controlled smart chargers out there,
why are no 12V smart chargers for our ebikes?

Seems that -smart charge profile- could be ported to a 12 v battery input.

THE GOAL:
With a large enough battery, I could recharge both ebikes a few times.
It's gonna take a BIG battery. Trying to keep it light... ha ha.
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1990 Westy Full Camper

[Love My Westy]

I found this:

https://www.bike-discount.de/en/buy/bosch-charger-12v-dc-dc-travel-charger-451743

The only problem is that they Bosch doesn't make it anymore. I don't know why.

[vwhammer]

Well you sorta answered your own question.
Not many places are doing 12 volt 48 volt chargers because the 12 volt systems that many people use are not big enough.
They could only be used in specialty applications.
Many are catered to marine use.

I was looking to do a 48 volt house battery for my van and charging it with a 12 volt alternator but all I could find for chargers were pushing nearly $1500.

That's more than I will have in my battery.

I did find a chinese source for some 48 volt alternators or I could possibly rewind one I have so it would put out 48 volts but I decided that a 24 volt system makes more sense since there are already 24 volt alternators on the market.

If you watch any automotive engineering news you might have seen that a lot of companies are talking of switching to 48 volt systems for cars.

Anyway I am trailing off topic a bit now.

How much do you ride that you might need to charge your bike so often.
I can shred in 2wd mode off road for nearly 30 miles before my battery is gone and my motors stop.

On road I only use about 150 to 250 watts and could probably go for 50 or 60 miles with assist 100% of the time.
I have ridden 40 miles with assist and still had plenty of battery left.

Of course hills will change that number a lot.

[Team WorldTour]

Maybe I'm just a backwoods old school type, but what the hell is wrong with a regular mountain bike? Change gears, keep petaling. You are not going to get fit on an electric bike.
_________________
1990 Feldjäger Syncro AAZ
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"Where am I going? And what am I doing in this handbasket?" -Nicodemus Jordan
When All Else Fails: Lather, Rinse, Repeat!

[Love My Westy]

Snarky question:

[danfromsyr]

Why would you ASSUME all bike riding is for 'fitness' and not pleasure.
wait till you get some old knees too.

[Team WorldTour]

[danfromsyr]

just trust that not all see the world and it's activities or experiences through the same rose colored glasses as you do.

I'll applaud you for your efforts, and commitments, both past and current..
I'll thank you for your service in a thankless world and try to be a better me myself even though I'll often fail at it.

but don't question why I'd want a cool ass electric bike.. and stay the heck out of my road in spandex and cleats.. see I often fail at being a better me.

fwiw, I don't have an electric bike (yet) but they're the moped of the 21st century.
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[pdm777]

I use the electric MTB when camping,
typically about 20 miles/day.

My new bike has the Bafang Ultra motor,
very powerful 750+W

Typically get 20-30 miles, however if you lean
into the throttle, only about 15 miles. FAST!!!

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1990 Westy Full Camper

[Team WorldTour]

I don't have an e bike, spandex or cleats.
I do my riding in cargo shorts and Vans.
I also don't have rosey glasses, either.
I just didn't see the point of e bikes, and spoke out my of ass, but apologised when called on it.
I will let you get back to your ebike debate. I'll never afford one anyway....
_________________
1990 Feldjäger Syncro AAZ
Click to view image
H6 Subaru Engine Swap Thread
WV2ZZZ25ZFH094138(x)/ WV2YB0257LH057308(x)/ WV2ZZZ25ZLG113270/
"Where am I going? And what am I doing in this handbasket?" -Nicodemus Jordan
When All Else Fails: Lather, Rinse, Repeat!