rebuilding a battery

[JamesW]

I'm coming to the conclusion that at least 90% of the reliability issues that I am suffering from with my conversion kit are due to the fact that the battery is a frog mount one.
I always cycle to work with panniers and my bike frame is aluminium so I'm trying to work out a more reliable way of mounting the battery.
I am concerned that the battery in its existing hard case within the frog shell may be too wide to mount in a pannier style battery case and that even if it wasn't I would have trouble mounting my ortlieb panniers on the rack.
Theoretically my commute is 20 miles each way. I reckon that I have only manage to do the full commute around 20 times in the last year due to reliability issues and me being worried about not being able to make it!
(The conversion kit was meant to save me the year's train fare of over £1500, but I've been on the train every week last year, so I'm not impressed with my saving so far.)

Ideally I think I would reshape the battery and mount it in a bottle mount case to move the weight forward and the centre of gravity lower. Anyone got any ideas if this is possible (I don't want to pay another £300 for a new 36V battery when the one I have is perfectly good, it just has an appalling mount which is not fit for purpose - which I am dealing with, see Section 75 of Credit Card act for this.)

James

 

[Deleted member 4366]

You have to open the case to see what's inside. There's lots of different cell arrangements that they use. You should be able to take the cells out and put them in your own box in the triangle.

 

[JamesW]

You have to open the case to see what's inside. There's lots of different cell arrangements that they use. You should be able to take the cells out and put them in your own box in the triangle.

So you think I would be able to switch to a bottle style battery case without too much difficulty? Will I be any less likely to get electrical contact issues then?
- What would you do Dave?

 

[Deleted member 4366]

You have to make your own case.

 

[JamesW]

You have to make your own case.

so I cant just get a bottle battery case from bms battery or something like that?
I'm quite happy to stop using the frog box and don't really want to make my own case as my skill lie more in woodwork - I can solder for bodging and do the wiring, but when it comes to welding or fibreglass that's not really my area of expertise!

 

[JamesW]

If I have to go down the build your own case route, I think It would probably be easier to design a better mounting system for the frog batter that I can get a local garage to weld onto the top of my pannier rack (with properly engineered tolerances and none of this Chinese just about rubbish that is resulting in the movement of the battery case.

 

[Deleted member 4366]

A bottle battery is round. A frog battery is square. Can you put a square peg in a round hole? If you show us the inside of your battery, maybe we can help.

 

[JamesW]

Job for the weekend then to take pics

 

[patpatbut]

how about frame bag like this?

http://www.ebay.co.uk/itm/Ibera-Bike-Triangle-Front-Frame-Tube-Bag-Large-Cycling-Black-NEW-IB-FB1-L-/171123593943?pt=LH_DefaultDomain_0&hash=item27d7c2d2d7

No DIY skill needed

Pat

 

[JamesW]

how about frame bag like this?

http://www.ebay.co.uk/itm/Ibera-Bike-Triangle-Front-Frame-Tube-Bag-Large-Cycling-Black-NEW-IB-FB1-L-/171123593943?pt=LH_DefaultDomain_0&hash=item27d7c2d2d7

No DIY skill needed

Pat

Thanks for the suggestion pat but I already dismissed that a while ago.as I would prefer not to got the frame bag route as it is not as solid as a plastic case and the battery gets fitted and removed twice a day. Frame bags are not as quick and convenient for this as a reliable solid mount ( from my experience carrying tools - I prefer to.carry them in the frame bag I made at the bottom of my pannier now as its as much about speed as reliability for me.

 

[Deleted member 4366]

It doesn't take much to make a nice box out of wood. All you need is some 3mm plywood, some 25mm square strip and some PVA. Glue it and plane the edges round. Bolt it to the bottle fixings and make a bracket to wrap round the frame at the back or top. Simples. Where there's a will, there's a way!

 

[cwah]

It doesn't take much to make a nice box out of wood. All you need is some 3mm plywood, some 25mm square strip and some PVA. Glue it and plane the edges round. Bolt it to the bottle fixings and make a bracket to wrap round the frame at the back or top. Simples. Where there's a will, there's a way!

but it won't be quick release anymore!

 

[JamesW]

Was more concerned about how robust a wooden box would be in the face of water ingress as sealing it is obviously more difficult than plastic or metal due to its porous nature.

 

[JamesW]

Was also concerned about how much faster wood wears than plastic or metal for any repeatable location positioning and locking of the battery. But if you think wood is a sensible material that won't have me rebuildinch the box every few months.... ?

 

[patpatbut]

Thanks for the suggestion pat but I already dismissed that a while ago.as I would prefer not to got the frame bag route as it is not as solid as a plastic case and the battery gets fitted and removed twice a day. Frame bags are not as quick and convenient for this as a reliable solid mount ( from my experience carrying tools - I prefer to.carry them in the frame bag I made at the bottom of my pannier now as its as much about speed as reliability for me.

Hi James,

I have been using frame bag for my 5 kgs battery for 1 year and 3 months everyday for my 28 miles
commute and the bag reminds strong. What you need to pad the frame bag with solid foam.

You can get a really solid frame bag from Paul at Em3ev

The only downside is you can't lock the battery in the bag as it is not safe enough

Pat

 

[oigoi]

The battery for my bike is an awkward square shape, I just put it in one of my panniers (altura orkney, quick release) and they have a handle on top to carry it inside and charge it up

 

[Deleted member 4366]

Was also concerned about how much faster wood wears than plastic or metal for any repeatable location positioning and locking of the battery. But if you think wood is a sensible material that won't have me rebuildinch the box every few months.... ?

It doesn't wear at all. Put washers either side of the bottle mount fixing screws:
http://www.pedelecs.co.uk/forum/threads/rocky-mountain-element-conversion.12481/

You don't have to fill the complete triangle. This one had a bigger battery and two controllers, so needed to be bigger:

 

[JamesW]

Frame bag would interfere with my airzound mounting, so that would need a rethink.
Twice a week I have 2 panniers of stuff to carry so battery has to mount outside a pannier.

I am coming around to the idea of building a box to house the battery (possibly wooden) and mounting the charger inside to so when I take out off for recharging all I have to do is plug in a kettle lead. Where on the bike it mounts and how along with how simple can I make the battery connection for quick connect/ remove remains to be thought about.
But on the other hand I do have 2 frog cases, do if I could just get a frog case to mount reliably and not move during the ride it might be even simpler!

 

[JamesW]

Looks gorgeous Dave, I'll have to look at that thread and understand how the battery comes off for charging. (You know how quick the frog is to fit and remove - the 1 thing I love about it)

 

[oigoi]

Could you put a bungee or something similar on the frog battery to hold it in place more securely?