Replacing Frog battery

[russell]

I have 2 x 20" foldup electric bikes purchased from Tesco 4 years ago which have been brilliant, they are called the Shopper.

1 of the bikes fell over and is now not turning on properly, when it does turn on the minute I pedal the power goes off.

When the bike fell over, it caused damage to the battery box also to the battery carrier. When I turn the ignition on the power light does not always come on. I think the battery is a 5Ah, I am thinking of buying a replacement battery and holder complete with new ignition which is on Ebay at £179 but it is a 10.4Ah, can I use this one or will it have to be a 5Ah batterythis onebut

I

When I turn the

 

[wheeliepete]

Sounds like you have a bad battery connection,prob. from the damage to the battery carrier. As long as the battery is the same voltage, it can be any Ah capacity. You may need to change the connectors. Yose Power sell frog batteries, they have a 36v 13.6 Ah with decent LG cells for an extra £10.
https://www.yosepower.com/en/product/Frog-Electric-Bicycle-Battery-LG-Cell-24V10.4Ah/16Ah/-36V10.4Ah/12.8Ah-Lithium-ion-E-bike-Battery-77.html

 

[vfr400]

Have a look how the two prongs on the battery carrier engage with the slots in the battery when you slide the battery in.

It could be that the plastic part that holds the two prongs is broken, in which case you can glue it back together with epoxy.

Secondly, it could be that the carrier is bent downwards so that the prongs don't go into the battery far enough, in which case you just need to bend it back up again.

Finally, the connectors inside the slots in the battery are like leaf springs so that they clip onto the prongs. I've seen them where they're bent apart and don't make proper contact. It's not difficult to open the battery by unscrewing the 4 screws, remove the piece that holds the prongs by unscrewing one or two more screws, then bend them back into the right shape with thin pliers until there's no gap between the two sides. You need to be careful not to let the two contacts touch each other because they're live, so put some tape around one while you work on the other.



When your bike fell and knocked the battery, any of the above or even all of them could happen.

Don't forget to check that the motor wire isn't damaged where it comes out of the motor.

 

[russell]

Sounds like you have a bad battery connection,prob. from the damage to the battery carrier. As long as the battery is the same voltage, it can be any Ah capacity. You may need to change the connectors. Yose Power sell frog batteries, they have a 36v 13.6 Ah with decent LG cells for an extra £10.
https://www.yosepower.com/en/product/Frog-Electric-Bicycle-Battery-LG-Cell-24V10.4Ah/16Ah/-36V10.4Ah/12.8Ah-Lithium-ion-E-bike-Battery-77.html

Thank you for your information, I have had a look at this website, first impression was brilliant but couldn't find stock or delivery charges. I have emailed them for more info. Do you know of anywhere who sells the just battery carrier, it might be the cheaper way of checking whats happened.

 

[russell]

Have a look how the two prongs on the battery carrier engage with the slots in the battery when you slide the battery in.

It could be that the plastic part that holds the two prongs is broken, in which case you can glue it back together with epoxy.

Secondly, it could be that the carrier is bent downwards so that the prongs don't go into the battery far enough, in which case you just need to bend it back up again.

Finally, the connectors inside the slots in the battery are like leaf springs so that they clip onto the prongs. I've seen them where they're bent apart and don't make proper contact. It's not difficult to open the battery by unscrewing the 4 screws, remove the piece that holds the prongs by unscrewing one or two more screws, then bend them back into the right shape with thin pliers until there's no gap between the two sides. You need to be careful not to let the two contacts touch each other because they're live, so put some tape around one while you work on the other.

View attachment 29065

When your bike fell and knocked the battery, any of the above or even all of them could happen.

Don't forget to check that the motor wire isn't damaged where it comes out of the motor.

Thank you for your information. I will check all of this tomorrow, I dont think the wire from the motor could be affected because that is on the opposite side to where the bike fell. I am 74 years of age and this lovely little bike is so important me and keeps me in touch with everything and everybody otherwise I would be stuck at home rotting away

 

[wheeliepete]

Thank you for your information, I have had a look at this website, first impression was brilliant but couldn't find stock or delivery charges. I have emailed them for more info. Do you know of anywhere who sells the just battery carrier, it might be the cheaper way of checking whats happened.

Click on "Berlin", then select the battery you require and stock will appear below in brackets( ). Delivery is around £15 in 3-5 days by Parcel Force. It's deff. worth looking at the damage to your carrier, it may be simple fix. I've not seen the carrier for sale seperately anywhere, You may find an empty case with the carrier on Aliexpress from China.

 

[russell]

Click on "Berlin", then select the battery you require and stock will appear below in brackets( ). Delivery is around £15 in 3-5 days by Parcel Force. It's deff. worth looking at the damage to your carrier, it may be simple fix. I've not seen the carrier for sale seperately anywhere, You may find an empty case with the carrier on Aliexpress from China.

Thanks again chap but when I click on Berlin it only shows stock of the 16Ah

 

[sjpt]

As wheeliepete said in his first reply, it is the voltage should match. It may be quite awkward if the connectors don't match. The Ah is not critical as long as it gives as big a range as you need. Most bikes are 36v, several are 48v, and quite a few more basic ones are 24v.

p.s. If it is the Hopper (not Shopper) it is 24v. https://www.tesco.com/direct/hopper-20-folding-electric-bike/215-7386.prd?source=others

 

[wheeliepete]

it only shows stock of the 16Ah

That will work fine if you need 24v, give you alot more range and reduce the need to charge so often.

 

[russell]

That will work fine if you need 24v, give you alot more range and reduce the need to charge so often.

Thank's for that, but I have just ordered one from Aliexpress deivered £134 which is brilliant, I'm happy to give it a try, if it turns out to be something else I can always sell it or sell the bike as well, spare/repair.. Thank you again for all of your help. I will let you know what happens

 

[russell]

Thank's for that, but I have just ordered one from Aliexpress deivered £134 which is brilliant, I'm happy to give it a try, if it turns out to be something else I can always sell it or sell the bike as well, spare/repair.. Thank you again for all of your help. I will let you know what happens

Thank's for that, but I have just ordered one from Aliexpress deivered £134 which is brilliant, I'm happy to give it a try, if it turns out to be something else I can always sell it or sell the bike as well, spare/repair.. Thank you again for all of your help. I will let you know what happens

.

Whilst waiting for the new battery to arrive, I have taken the suspect battery apart and found that the plastic piece that goes over the metal contacts and holds them in place is broken. I had a problem taking the screw out that holds the remaining bits of the bit of plastic but eventually did it. I think there is a very good chance that is creating the problem, when pushing the battery on the contacts just move inwards.

I have spent most of the morning trying to find anyone supplying the battery case without success. Aliexpress, don't appear to offer one.....

 

[wheeliepete]

when pushing the battery on the contacts just move inwards.

I'm sure with a bit of cunning bodgery, sorry modification, you could find a way to support them. Post a photo and somone may have an idea or two. There's always a way!Shame to srape a usable battery.

 

[vfr400]

Buy a pair of XT60 connectors and a meter of 14g silicone wire. Chuck the broken piece and the prongs, and solder the XT60 with male pins to the two wires that were attached to the prongs. Open the battery, take out the connectors I showed you above and cut them off, then solder two 9" lengths of the wire to the battery wires, bring them through the holes where the connectors were and solder on the XT60 with female pins. Make sure you get all the wires to the correct polarity to avoid big bangs and lots of stars.

Rest the battery on its platform, connect the XT60s, slide the battery on and lock it. You now have a connection system that will last a lifetime without further problems.

 

[russell]

I'm sure with a bit of cunning bodgery, sorry modification, you could find a way to support them. Post a photo and somone may have an idea or two. There's always a way!Shame to srape a usable battery.

Well I went for it and bingo result.
I hunted in my garage for something to shape and at the same time be able to bolt/screw in place. I then decided I would whittle a piece of hardwood down and make it a tight fit and it works a treat. Connected the battery back up and everything appears to be working fine although I haven't been out for a proper ride but fingers crossed. I am so very grateful for the kindness of people on this forum thank you.
Regards Russell

 

[russell]

Buy a pair of XT60 connectors and a meter of 14g silicone wire. Chuck the broken piece and the prongs, and solder the XT60 with male pins to the two wires that were attached to the prongs. Open the battery, take out the connectors I showed you above and cut them off, then solder two 9" lengths of the wire to the battery wires, bring them through the holes where the connectors were and solder on the XT60 with female pins. Make sure you get all the wires to the correct polarity to avoid big bangs and lots of stars.

Rest the battery on its platform, connect the XT60s, slide the battery on and lock it. You now have a connection system that will last a lifetime without further problems.

.
Thank you for your very helpful message which I will keep in mind should my problem return but in the meantime I am very grateful to you all.

 

[wheeliepete]

Nice one Russell, I too have used wood in the past many times to repair/reinforce broken moulded plasitc items, I'm sure it will last the remaining life of your battery. Comes in very handy having multiple skills/hobbies.