Charging ebike batteries when not on hook up

paulj

paulj

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I’m thinking about buying the AS Mk3 electric bike,what set do I need to recharge the batteries when not on hook up?,I currently have a compass cv20 campervan
Thanks in advance for all help received
 
The batteries are 36v so what would be a good size inverter to have and how do you install it

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We have a 600w inverter, 110 ah battery and 140w panel. The most valuable bit is the victron battery monitor. We can charge the bike batteries on a sunny day and check that the van battery never discharges too far. It means we have to keep an eye on it and may have to charge for an hour or so at a time but it works. Keep the bike battery charged up whenever possible, dont run it right down.
 
I bought a Bestek 300w Sinewave inverter, and wired it directly to the leisure batteries (via a 30A fuse). It enables me to charge up my 2 ebikes (Rally Arrays) whilst driving. The inverter does have a cigar lighter plug option, which is best stored in a dustbin. I don't have solar so only use it when engine is running.
 
My ebike has a Bosch motor and 625Wh battery, it’s supplied with a mains 2 Amp charger with a rated input of 100-240v 50\60 Hz 1.6 Amps. I have fitted a Victron 375W 240V inverter in my van. Ohms law suggests that the charger should draw a maximum of 160W, well within the rating of the inverter, at 100% efficiency one could expect a draw of 13.3 Amps. When I plugged the charger into the inverter with the battery connected charging started immediately but the inverter 12V current draw was only 7.5 Amps (90W) Given that the rated efficiency of the inverter is 89%, and that the charge time is specified as 8.8 hours from flat, (an unlikely scenario) which would consume 66 Ah I think that this is pretty good and well within the capacity of my batteries (190Ah) and solar(200w)/vehicle charging system.
 
My Inverter is 1000w, connected to the leisure batteries with in-line 30amp fuse.its tucked in close to the batteries near the fuse box and not really accessable so I installed a further accessable13amp plug socket which is plugged into the inverter only. Use this for charging the bike batteries whilst running and on sunny days. Alternately. Plus can also plug in other items for charging and using, microwave for a few miins as an example if off grid and we have good solar. (y)
 
I have recharged at railway stations and supermarkets (always ask first and offer to pay) - I've only been refused once :)

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Chris CM said:
My ebike has a Bosch motor and 625Wh battery, it’s supplied with a mains 2 Amp charger with a rated input of 100-240v 50\60 Hz 1.6 Amps. I have fitted a Victron 375W 240V inverter in my van. Ohms law suggests that the charger should draw a maximum of 160W, well within the rating of the inverter, at 100% efficiency one could expect a draw of 13.3 Amps. When I plugged the charger into the inverter with the battery connected charging started immediately but the inverter 12V current draw was only 7.5 Amps (90W) Given that the rated efficiency of the inverter is 89%, and that the charge time is specified as 8.8 hours from flat, (an unlikely scenario) which would consume 66 Ah I think that this is pretty good and well within the capacity of my batteries (190Ah) and solar(200w)/vehicle charging system.
Click to expand...
Sounds about right, my 300w inverter could theoretically draw 25-25 amps hence my 30amp fuse. I used to be an electronics design engineer specialising in....Inverters!! We always sought 90% efficiency, which was usually obtained around the 50-60% load. The quiescent current losses make bigger inverters 1000w etc. very poor efficiency at modest load levels. it's more efficient to have a 300-400w unit these ebike batteries will have an initial surge but settle in seconds to draw around 100w. Yours should easily suffice to charge a couple of ebike batteries simultaneously.
 
If you don't use the e-bike much, you may get away with charging through an inverter. Some e-bike batteries have around 600Wh capacity. That's the same as a 100Ah habitation battery, so a full recharge would flatten it.
Using an inverter requires a high current from the battery for an extended period, which is not a particularly good way to treat a battery. Running the engine to compensate would overcome that but electricity generated that way is rather expensive.

If e-bikes had a regen function (eg. for when going down hill), you could perhaps use that to regenerate on a stand after a ride. Thus putting back what you took out, at your 'leisure', at a pace you can sustain.
 
Ok, one option you could consider, but it is not cheap. However, dependant upon what you may need to buy to implement your off grid solution then these might be an alternative that although not cheaper, might not be that much dearer but save lots of time to implement.

The link below is to a YouTube channel where two of his videos recently deal with (1) providing power off grid power via a portable power bank, where one of the charging options for the power bank is either existing or portable solar to charge it. He shows three units but the top of the range is mega expensive. He has recently bought two e-bikes, make and model irrelevant, but in the middle of the review video it shows him using the mid range power bank which has the input from the solar charging it, at the same time that he is using the power bank to charge his bike batteries.

As I said, an option, may not be cheaper than a permanent in-van setup option, but might be something to consider......

www.youtube.com

Gadget John

Tech reviews and advice videos related, but not limited to, van dwelling or living off grid.
www.youtube.com www.youtube.com
 
any reviews good or bad for the AS Mk 3 electric bike I’m thinking about getting one
 
Jimbohorlicks said:
My Inverter is 1000w, connected to the leisure batteries with in-line 30amp fuse.its tucked in close to the batteries near the fuse box and not really accessable so I installed a further accessable13amp plug socket which is plugged into the inverter only. Use this for charging the bike batteries whilst running and on sunny days. Alternately. Plus can also plug in other items for charging and using, microwave for a few miins as an example if off grid and we have good solar. (y)
Click to expand...
Your fuse at 30A will limit your inverter output to about 300w, I would use at least 100A fuse.
 
You have to 'pay' for what you use. In other words, put back the energy that you take out.
I think that many may not use their e-bikes much, so won't need to replenish as much as others,
but e-bikes can consume a lot of energy and that has to come from somewhere...
 
paulj said:
any reviews good or bad for the AS Mk 3 electric bike I’m thinking about getting one
Click to expand...
The quoted battery capacity is very small for an ebike, 8Ah/288W/h I would be very surprised if you get anywhere near the quoted 60km range unless you’re cycling somewhere very flat and don’t use much assistance, but it is supposed to be a mountain bike ?. Also, Gadget John fitted a supplied accessory throttle, this is illegal In the EU for an EPAC so I wonder if this bike is type approved? It may be apocryphal, but I read somewhere that the Spanish police were checking ebikes for the correct markings!
 
paulj said:
any reviews good or bad for the AS Mk 3 electric bike I’m thinking about getting one
Click to expand...
Bought ours second hand, had no issues. Fold up for storage and fit on the bike rack. Batteries and saddles stored in the van.

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Our bikes have 400 W Bosch batteries, I have a 1000 watt pure sine wave inverter & 3 x 80a/h Gel batteries & 300 watts of solar it works well for us.
 
Augusta08 said:
I bought a Bestek 300w Sinewave inverter, and wired it directly to the leisure batteries (via a 30A fuse). It enables me to charge up my 2 ebikes (Rally Arrays) whilst driving. The inverter does have a cigar lighter plug option, which is best stored in a dustbin. I don't have solar so only use it when engine is running.
Click to expand...
Is that the same inverter shown below?

Amazon product ASIN B076P9PGX3
If so we bought one works very well for the toothbrush and laptop but not for the ebike batteries as the charger draws about 250w, too much for the 12v plug had wondered about changing the power lead but not sure how.
 
paulj said:
any reviews good or bad for the AS Mk 3 electric bike I’m thinking about getting one
Click to expand...

I'm not sure if our AS bikes are mark 2 or mark 3 but they do exactly what we need them to do. I'll use the bike rather than the car to get to my friend's house (about 4 miles and a steep hill plus a long not so steep hill). They are heavy and not as pretty as some of the more expensive bikes. The step through is very low which is a major consideration for me.

We did change the saddles which has made the ride a lot better. Some bike shops have saddle fitting facilities. You sit in a piece of memory foam so measurements can be taken - the size of your posterior doesn't always match the width of your sit bones. I thought I'd be looking at a quote of £100 for a saddle but the best one for me was less than £20. Martin's was only £15 !!!!!!

After sales service has also been top notch :)

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Do e-bikes batteries need a pure sine wave inverter for charging when driving or would my 1500 watt modified work ?
Battery is 36v 10.4Ah 374.4 Wh Charge max 1.8A
 
paulj said:
The batteries are 36v so what would be a good size inverter to have and how do you install it
Click to expand...
Voltage is not the issue as the bikes charger will see to that. What is important is the chargers input wattage or amperage.
Too small an inverter and it will either overheat or trip out.
Too big and its wasted as the excess power has nowhere to go.
Installation is easy, direct to the battery as close as possible with a suitably rated fuse in the Pos cable.
 
Neilfg said:
Is that the same inverter shown below?

Amazon product ASIN B076P9PGX3
If so we bought one works very well for the toothbrush and laptop but not for the ebike batteries as the charger draws about 250w, too much for the 12v plug had wondered about changing the power lead but not sure how.
Click to expand...
That's like it, as I said cut the cigar lighter plug off throw in the bin, then put on a couple of connectors from Halfrauds.

https://www.halfords.com/tools/fuse...-connectors-15-amp-insulated-10mm-869768.html

And wire to leisure battery. Easy enough the inverter is even protected against reverse polarity so it's hard to get it wrong.
 
Figaro said:
Do e-bikes batteries need a pure sine wave inverter for charging when driving or would my 1500 watt modified work ?
Battery is 36v 10.4Ah 374.4 Wh Charge max 1.8A
Click to expand...
It depends on the charger, I decided with the price of Bosch spares it wasn't worth the risk.
 

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