My ebay Electric folder

[wurly]

G'evening folks
I thought i'd share my lastest project with you all.

I've been looking for a suitable folding bike for a while, most have been outside my price range, but i found this on ebay with a suspect battery.

It was made by CEPV and is about 5years old. It was taken around in a motorhome(as a lot of them are) but from what i can make out, didn't get much use, about 100miles. It certainly looks good condition, unfortunatley the battery isn't.

First thing to do is clean it.

I got rid of the silly bar ends and lubricated the brake cables (i don't think they have ever been done). Gave it an all round service while the battery was charging up.

Today i gave her a test ride. Expecting to get no further than the end of the road i was pleasently surprised to make it across town and the battery didn't cut out once.

Mmmm.
Time to really test it, i decided to take the hilliest roads home and sure enough, once i had committed myself to that route the battery cuts out. By switching it off and restarting i managed to limp home. I wouldn't have wanted to pedal it much further tbh.

 

[wurly]

So, the battery is still useful if i don't want to venture too far, but a replacement battery is next on the agenda.
Time to open it up and see whats what.

It's a 24V phylion battery with 7 10ah cells which have expanded slightly.

So what are my options?

I was thinking replacing the pack with some A123 cells. Hoping Jerry will 'chip in' here.

 

[Deleted member 4366]

Is it 24v or 36v? Whatever, it'll go really well with a pack of 12S lippos in that frog case.

 

[Deleted member 4366]

Looks like 24V, so you'll need a new controller too.

 

[wurly]

Lol, i thought you would suggest that!

Not sure yet, it would mean replacing the controller and getting myself geared up for balanced charging.

This isn't going to be a flyer, i think i would like it to have more range and cells that could take a higher discharge rate. The originals cells obviously couldn't.

Those zippys fit just right. Time to look at the hobbyking website.......

 

[amigafan2003]

You could always go for the 5s 8ah packs for 37v. Controller 'might' be able to take that.

Or if you don't like the idea of lipo you could get two ZIPPY Flightmax 8400mAh 4S2P 30C LiFePo4 Pack that should fit ok and will put you back near 24v (26.4v nominal).

 

[Deleted member 4366]

I think you'll struggle to get any more than that with A123 or Headway cells. They take up more space, and 10aH of A123 will be expensive.Another option woould be to get a 36v frog battery from somewhere. I got a nice one off ebay for about £170 a few months back, but I've llost the link now.

 

[wurly]

I'm not going to do anything real quick, as i said the folder does run ok, but new battery is going to be needed some time in the near future.
The zippy packs certainly look value for money. I might go for lipo as i would need to get a balance charger anyway. It just adds to the cost. I'm sure Jerry wasn't balance charging his A123 pack as it didn't require it, although, i think he had to replace one cell.

Have you ever bought from the HK DE warehouse? are there any import duties or taxes?

 

[Deleted member 4366]

No duty from Germany (DE), but they never seem to stock the 8000maH Zippies. You can get an iMax charger on Ebay for about $18 and anothe £5 for a power supply unless you've got a redundant Playstation brick.

 

[shemozzle999]

If you want to keep your great little find as stock built, without any changes, but double the original capacity (24v,15aH) and get a spare battery carrier and charger to boot, then I would purchase one of these as I did (approx £162 delivered - choose cheapest method - only slightly more than you paid for the bike) - still going strong for me:

little frog

I took about 5 weeks to deliver, but you say your not in a rush so....

 

[Blew it]

Thanks for that link shemozzle999, My four-year-old Alien Lynx is in need of a new battery, 'Little Frog' will do nicely

 

[jerrysimon]

I was thinking replacing the pack with some A123 cells. Hoping Jerry will 'chip in' here.

Nice little bike especially the suspension back and front

The challenge I find with small folding bikes is getting the seat high enough. In terms of A123 cells I guess you would only need 8 and maybe split them down into two 4s1p. That said this will only give you 2.3Ah which is unlikely to give you much more range than the existing iffy one. Mine will do about 8-10 miles in flat Cambridge putting in about a 1/3 of the pedal effort required.

For more uneven terrain I would suspect that 5 miles would be the max. I have now done 4000 miles in nearly three years with one cell failure. That said one has just failed again this week. As with all these batteries I don't think its good to take packs below about 30% capacity which is probably why I lost a cell after the first year exhausting the pack on each days commute. I now always charge at work. Apart from the initial balance when built they can be bulk charged with little loss in balance for months at a time. I keep meaning to do a balance every 2-3 months or so, but mostly never get round to it.

Then again they are pretty cheap. This pack cost me around £70 to make.

An 8s one would be even cheaper.

8 A123 2300mah 3.3v new original cell welding ser | eBay

PS these guys are cheaper for a Frog battery and a recent poster said their service was good. BMS have been getting some bad press recently

http://www.greenbikekit.com/index.php/24v10ah-frog-lifepo4.html


Regards

Jerry

 

[jerrysimon]

Even with my £70 batteries I must admit these begin to look quite good. All a lottery with import duty of course.

36V8.8AH bottle battery/ dolphin battery for electric bicycle, mounted on e-bike frame online store for electric bicycle components-GreenBikeKit.com

Or these cheap and VERY light at 2.6kg

http://www.greenbikekit.com/index.php/36v-lithium-ion-rear-rack-battery.html

Though these slightly higher capacity ones are claimed to be 2.3kg so that can't be right ?

http://www.greenbikekit.com/index.php/36v-9ah-panasonic-lithium-ion-rack-battery.html

Or maybe they are hence the higher price.

Jerry

 

[jackhandy]

What would you think would be the final price, in sterling, for the bottle battery, Jerry?

I bought an act20 helmet camera from HK this week & dont't seem to have been stung for any extras, but the battery might be a different kettle of strawberries, I guess.

 

[jerrysimon]

I have no idea as I said its all a lottery.

There comes a point though when backup support and returns make it better to buy in the UK.

Regards

Jerry

 

[Deleted member 4366]

You nearly always get caught for duty on batteries. My theory is that they get close inspection after x-ray at customs, while as motors, wheels etc just go straight through.
Those bottle batteries look nice, but note the continuous discharge rate of only 10amps. The data for the others isn't clear, but I'm pretty sure the Panasonic ones are 2C = 20amps continuous. That's why they're more expensive. The Headway batteries are very strong, but they're a little more bulky and heavy. I've just come back from a 40 mile ride with my 12aH 36V one and it's still showing 39.2V! I think they're rated at 5C = 60 amps. Unfortunately, they don't fit in a frog case, but worth considering for anybody else.

 

[wurly]

Thanks for the links everyone. I must admit, having ridden it, i would be more inclined to get higher discharge rated batteries. The bike doesn't lend itself to high power pedalling so i think i might be leaning on the batteries quite a bit.

The replacement frog battery looks tempting just for the ease factor, but i'm sliding towards lipo...
Am i right in thinking that balance charging can be achieved using a 12V car battery as a power supply? I don't have a home for it yet (lack of space in the house) so it's stored in the back of the car. Can you see what i am thinking?

Shemozzle, you must have been one of the 878 watching it.

 

[shemozzle999]

No, just checked out the completed listings and knowing how savvy Pedelec members are I used the cheapest item filter and there it was!

Regarding the frog battery rated 15aH you can draw a constant 15A with a 30A limited burst more than enough for a 200W motor.