Fuse Keeps Blowing...

Nealh

Esteemed Pedelecer
Aug 7, 2014
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Well worth considering a Silverfish lithium celled battery, they will come with a new fitting docking kit and a charger, the advantage over SLA is they will give better range and usable power. Plenty on ebay to choose from as well for about 10ah to 15ah.
Just check the measurements to make sure it will fit .
 
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vfr400

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Jun 12, 2011
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One of these will probably fit in your case with plenty of room to spare. The size will be about 195 x 70 x 75. You have to buy the charger separately. They have a lot of other nice cell-packs too, but if you choose a different one, make sure that it can supply 20A continuous.
 
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gtd2000

Finding my (electric) wheels
Oct 29, 2019
21
1
It's a brushless motor and controller. I couldn't see all those wires in the other picture. It looks like one of your batteries leaked. The acid is not only very corrosive but also highly conductive. A good clean around all those terminals might be a good idea.

Was that blob on the red wire touching anything? It must have been close to the controller case.

What's that bare bullet connector for on the purple wire?


Try it now with everything out when there's no danger of that red wire shorting, but make sure you stick that connector in the battery the right way round, and make sure you reassemble it the right way round.
Sorry didn't notice your earlier reply.

I don't know the full history of the bike but I'm led to believe it was kept on the back of either a camper or a caravan. It doesn't look like it was actually used very much, tyres look original and are very much unworn. The grips still had plastic wrapping on them but I removed that.

I'm pretty sure that blob on the red wire was shorting on the controller (as you suggested), there was also only about 4 strands of wire making a connection with the terminal. Didn't take much to remove it and it's now connected on the inside of the post, similar to the black wire.

I can't see any evidence of leaks from the batteries but I've no idea if they are the original fitment?

I'm not sure which purple wire connector you are referring to?
 

gtd2000

Finding my (electric) wheels
Oct 29, 2019
21
1
I would consider buying a cheap Li-ion battery pack over new lead acid ones, as you will get much better range and reduce the weight of the bike. A silver fish case should fit were your existing pack is, although you may have to drill new fixing points to mount it.
The price of the first one is attractive, as it would be a bit more than double the price of replacing the lead acid batteries. :)
 

wheeliepete

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Feb 28, 2016
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The price of the first one is attractive, as it would be a bit more than double the price of replacing the lead acid batteries. :)
Think about how far you want to travel on the bike. More capacity = more money. VFR's suggestion has better quality cells in it and maybe less work as long as it fits your case. The silverfish case may be more work to fit, but has the charger and new battery connectors included.
 
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Nealh

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Aug 7, 2014
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The MH1 is a very good cell and LG in the most are highly rated, I think in the last few years there was only one cell that was a bit of a dog and that was the MG1 which is no longer I believe.
The new Mxx series are also meant to be very good as well as is the very well regarded MJ1.
 
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gtd2000

Finding my (electric) wheels
Oct 29, 2019
21
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Think about how far you want to travel on the bike. More capacity = more money. VFR's suggestion has better quality cells in it and maybe less work as long as it fits your case. The silverfish case may be more work to fit, but has the charger and new battery connectors included.
Think about how far you want to travel on the bike. More capacity = more money. VFR's suggestion has better quality cells in it and maybe less work as long as it fits your case. The silverfish case may be more work to fit, but has the charger and new battery connectors included.
This bike was really just a project to see if I could get it back up and running.

I knew the square root of nothing but at least now I know that somebody telling the battery is perfect isn't something to be taken at face value ;)

I'm perhaps thinking of selling this one and using the money to get a kit to put on my older Raleigh MTB.

Then again, this one would be fine for occasional use.

Decisions, decisions...
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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Yes, without looking well dodgy 20ah with only 4 cells 18650 in parallel. Panny's very good GA cell is only 3400mah they don't make a 5000mah cell, no one makes a 5000mah 18650.
 
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gtd2000

Finding my (electric) wheels
Oct 29, 2019
21
1
Yes, without looking well dodgy 20ah with only 4 cells 18650 in parallel. Panny's very good GA cell is only 3400mah they don't make a 5000mah cell, no one makes a 5000mah 18650.
I watched a few videos on YouTube where they tested a variety of 18650 batteries and most were only a fraction of their rated capacity. I'd suspect something like this type of battery may very well be made from the same low grade cells?

Also read about the dubious practice of putting new wrappers on old mobile phone batteries and selling them as new... :oops:
 

vfr400

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Jun 12, 2011
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Does this seem too good to be true?

US $71.71 39%OFF | 36V 20AH 10S4P electric bicycle battery pack 18650 lithium ion battery 500W high power 42V motorcycle scooter
There are no 5000 mAh 18650s, so the capacity is wrong. Maybe something went wrong with their maths because it looks like the same pack that Aerdu sell as the 10Ah one. Note also the 15A max continuous current, which is too low for you and means crappy cells.
 
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gtd2000

Finding my (electric) wheels
Oct 29, 2019
21
1
When you have something like this old bike, with no known spec or details etc...it's obviously setup to use 36v but what would occur if say 48v was used instead?

Would it simply blow the controller or burn out the hub motor?
 
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When you have something like this old bike, with no known spec or details etc...it's obviously setup to use 36v but what would occur if say 48v was used instead?

Would it simply blow the controller or burn out the hub motor?
Quite possibly burn out the controller, the motor is likely to survive.
 

vfr400

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Jun 12, 2011
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48V will give 33% more torque and speed. The motor won't have any problem with that.

Some 36v controllers can handle 48v and some can't. Controllers don't cost much compared with a battery, so it's always worth upgrading at the same time.

Your 36v controller will cut off at 31V when the battery is empty. For a 48v one, it should be around 40v, so there's a danger of running your 48v battery too low. Any 36V battery charge state indicator lights you have will be on all the time because the first one goes off around 37V, which is already too low for a 48v battery.

Also, old 36v controllers have rather crude power control. When you go up to 48v, it's better to have more precise control over the additional power.

Never buy a cheap controller. It'll work, but your riding experience and control over the bike will be a lot better with a nice one, like Kunteng (KT).
 

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