Mine was even older than that. Had a massive rear motor, small front chain ring and only 3 gears at the back. I fitted a 15.6 Ah lithium pack to it back in 2019 for £165. Battery is still like new and I think it will last many more years. With lead acid, it is so easy to kill them if you don't charge them frequently.

How did you connect the battery?

Was it just a standard 36v 15.6 Ah battery or did you have to find one with a specific criteria for the controller and brushed motor?

Assuming you had to buy a matching charger too?

How did you connect the battery?

Was it just a standard 36v 15.6 Ah battery or did you have to find one with a specific criteria for the controller and brushed motor?

Assuming you had to buy a matching charger too?

 

I used a silverfish type battery from Yose Power. It came with a charger. I got rid of the plastic box for the lead acid and built a plywood box to slot into the frame to put the silverfish into. I had to change the connector on the bike, which was like a kettle plug and attach the connector that comes with the battery. I've pasted a pic from a current eBay listing for Yose Power. However, it seems their prices have shot up for Silverfish recently! Was £40 cheaper in autumn last year. You might be better going for one of the Hailong style batteries:

 

 

 

If you don't like buying from eBay, you can also go direct from Yose Power's website, prices are similar or a bit cheaper even, just need to check if they will charge for delivery.

 

When you replace the connector from the battery to the controller, check the polarity of the wires. So when I cut the kettle lead plug off it had a brown wire and a blue wire, as you would on a mains lead. I assumed brown would be positive and blue negative and soldered this to the new battery connector. However, this was not the case! I was lucky and got away with it, but check first! You might not have the same configuration, but whatever you do, check several times before connecting.

 

Here is a picture of my Powabyke. Note the plywood box to house the battery. I left it open on one side for ease of access and used high density foam to stop stuff falling out. It also houses the new controller for the brushless motor. In the photo I was experimenting with dual motors, so there is a second controller on top of the box and some spaghetti . I replaced as many of the steel parts as I could with alloy etc and shed about 10kg from the weight of the bike.

 

Edited July 29, 20232 yr by WheezyRider

[mention=26000]WheezyRider[/mention] - thats brilliant - I was thinking along similar lines - the bike I have got was spares repair, the batteries are possibly dead (and heavy!), the charger is suspect, and the battery casing is broken and taped together with masking tape - so I was thinking of one of these from Yose Power in a wooden box and using the controller connector from the original battery:

 

https://yosepower.com/products/hailong-2-down-tube-battery?variant=39778406105223

 

That way I get to maintain original controller and motor (upgrade those later in stages) and also have a battery option for when I convert my Raleigh Pioneer

 

I like the rack with child seat - where did you get that?

Edited July 29, 20232 yr by steveh6883

[mention=26000]WheezyRider[/mention] - Have you got a pick of the inside of the box with battery removed?

You can save a lot of time, money and effort by opening up your battery bos, chucking the lead batteries and replacing with any decent lithium cell-pack that fits in the case. It's just 4 wires to solder.

You can save a lot of time, money and effort by opening up your battery bos, chucking the lead batteries and replacing with any decent lithium cell-pack that fits in the case. It's just 4 wires to solder.

What are the 4 wires?

Not having looked yet, I would have assumed 2 wires to controller connector

The battery box charger point would, I assumed, be the other 2 wires, but that would be defunct for lithium battery?

What are the 4 wires?

Not having looked yet, I would have assumed 2 wires to controller connector

The battery box charger point would, I assumed, be the other 2 wires, but that would be defunct for lithium battery?

Two for the charge port and two for the output connector.

Two for the charge port and two for the output connector.

I didn't think you could use a SLA charger on lithium battery and vice versa?

I didn't think you could use a SLA charger on lithium battery and vice versa?

You can if it's the right voltage. Also, many chargers have an adjuster screw in them to get the correct voltage. The difference is so small that it doesn't normally matter. What I meant was to connect the battery charge wires to the charger socket on the battery box, then use a standard lithium charger with the same standard connector to plug into the socket. The socket is XLR, the same as many 42v ebike battery chargers.

 

What voltage is written on your charger?

Do not use an SLA charger with Li-ion! 14.4 x 3 is 43.2 V, way over 42V needed for Li-ion.

I would buy a battery with a charger, that way you can be reasonably sure it will be right type and voltage etc.

 

It may be possible to tweak the Powabyke charger to give you 42 V, but unless you are happy to open up a mains appliance and find the right potentiometer and check the output with a calibrated digital voltmeter (assuming it even has one, not all PSUs have them), it's not worth the hassle.

 

I'm currently away from home at the moment, where my bike is, so I can't give you a pic of inside of the box right now. But it's quite simple, a 3 sided box of 9 mm external grade ply, with two strips of wood on the bottom so it sits securely on the diagonal bottom tube and does not wobble around. It is held together with external grade wood glue and then lacquered and painted. I put an old inner tube on the diagonal bottom tube so the paintwork does not get rubbed off etc and vibrations are absorbed.

 

I made the box as the battery would not fit inside the original plastic case that the SLA batteries were in. It also gave me somewhere to put the controller and hide excess cables.

 

The seat I got off Amazon quite cheap, about £15. Great for taking older kids around that are too big to go in most bike child seats. You do need a rack that can handle the weight though. I upgraded to a Tortec rack that can handle 30 kg, but still lighter than the original steel rack. The frame is not designed to have racks attaching to it near the saddle, so I made up two strips of 3 mm aluminium strip to attach to the saddle locking bolt, should be able to see that in the picture.

 

Another upgrade I recommend is to replace the brake callipers with Shimano Alivio, to improve braking performance and eliminate having to keep adjusting the ones that come with the bike.

Edited July 29, 20232 yr by WheezyRider

I would buy a battery with a charger, that way you can be reasonably sure it will be right type and voltage etc.

 

It may be possible to tweak the Powabyke charger to give you 42 V, but unless you are happy to open up a mains appliance and find the right potentiometer and check the output with a calibrated digital voltmeter (assuming it even has one, not all PSUs have them), it's not worth the hassle.

 

I'm currently away from home at the moment, where my bike is, so I can't give you a pic of inside of the box right now. But it's quite simple, a 3 sided box of 9 mm external grade ply, with two strips of wood on the bottom so it sits securely on the diagonal bottom tube and does not wobble around. It is held together with external grade wood glue and then lacquered and painted. I put an old inner tube on the diagonal bottom tube so the paintwork does not get rubbed off etc and vibrations are absorbed.

 

I made the box as the battery would not fit inside the original plastic case that the SLA batteries were in. It also gave me somewhere to put the controller and hide excess cables.

 

The seat I got off Amazon quite cheap, about £15. Great for taking older kids around that are too big to go in most bike child seats. You do need a rack that can handle the weight though. I upgraded to a Tortec rack that can handle 30 kg, but still lighter than the original steel rack. The frame is not designed to have racks attaching to it near the saddle, so I made up two strips of 3 mm aluminium strip to attach to the saddle locking bolt, should be able to see that in the picture.

 

Another upgrade I recommend is to replace the brake callipers with Shimano Alivio, to improve braking performance and eliminate having to keep adjusting the ones that come with the bike.

More interested how you connected to the original controller pins that the original battery would sit on, but it sounds like you removed the controller from it's original housing? Or is yours the model that had the controller on the handlebars?

 

You don't happen to still have the original plastic battery casing do you?

Edited July 29, 20232 yr by steveh6883

More interested how you connected to the original controller pins that the original battery would sit on, but it sounds like you removed the controller from it's original housing?

 

You don't happen to still have the original plastic battery casing do you?

 

My bike was really old and might be slightly different to yours. But the controller was in a box on the handlebars. It had like a kettle lead coming out of it that plugged into the battery box.

 

When I first started tinkering, I cut the kettle like plug off the cable from the controller to the battery, soldered on a connector to the silverfish battery and gaffer taped the battery in place of the plastic box. Later I made the plywood box for the battery. As time went on I did more and more mods, eventually getting rid of the controller, fitting a brushless motor, replacing the cranks and chainring, adding a decent derailleur...

 

I still have most of the old stuff I took off from the bike, including the motor. I am away from home at the moment though, so I can't take pictures of anything right now.

My bike was really old and might be slightly different to yours. But the controller was in a box on the handlebars. It had like a kettle lead coming out of it that plugged into the battery box.

 

When I first started tinkering, I cut the kettle like plug off the cable from the controller to the battery, soldered on a connector to the silverfish battery and gaffer taped the battery in place of the plastic box. Later I made the plywood box for the battery. As time went on I did more and more mods, eventually getting rid of the controller, fitting a brushless motor, replacing the cranks and chainring, adding a decent derailleur...

 

I still have most of the old stuff I took off from the bike, including the motor. I am away from home at the moment though, so I can't take pictures of anything right now.

Yes, sounds like yours was a different model

The one I have is a Eurobyke 6 with the controller inside a plastic housing at the top of the downtube(s)

I still have most of the old stuff I took off from the bike, including the motor. I am away from home at the moment though, so I can't take pictures of anything right now.

No problem. Be interested to see what you have left when you are back at home