Talking of Twist Batteries . . . .

[JohnInStockie]

Flecc, Grandad

With all the work you guys have done on Twist Batteries, did you see these on Batteryspace?

24V 13Ah NiMH Battery Pack ( 20xF) for Hi-Power E-Bikes or Robots - EB-H24VF12A

Let me guess, they are incompatible?

Thanks

John

 

[flecc]

No they are fine John, but the size and weight are a problem of course. A battery using those will be very bulky and perching all that weight over the carrier would make the bike a bit wobbly. Our D size cells can be 10 Ah now, so there's not much gain for those problems.

 

[allotmenteer]

No they are fine John, but the size and weight are a problem of course. A battery using those will be very bulky and perching all that weight over the carrier would make the bike a bit wobbly. Our D size cells can be 10 Ah now, so there's not much gain for those problems.

Also at about £180 without postage and customs duty (which would take the price to around £250, it's a very expensive option. Far better to buy two Powacycle 8Ah batteries I would think.

Paul

 

[flecc]

That's right Paul, Powacycle haven't been affected yet by the currently high world nickel prices which have caused Batteryspace prices to rise sharply, and hopefully they won't be. Certainly they've always been the best option hence my use originally described on the Twist website.

 

[Baboonking]

Be careful who you buy nimh batteries off. sometimes they have bad cells which when left in the pack will eventually damage the pack and create all kinds of problems. Always worth buying off someone with a warranty in the country your in, like powacycle. Ebikes.ca also very good (i don't work for them ) and actually cycle each pack to look for cell failure' before they ship them.

I don't recommend batteryspace at all. Quite a lot of reports now from different forums. The batteries are generally ok but unless your happy checking and changing weak cells you might have a big headache. Their chargers are also lousy and tend to overcharge the batteries. I use nimh and they're great batteries, I'm hoping my pack will last me many years. If there's a problem I'm happy to change a cell though.

 

[flecc]

Thanks for that cell info Baboonking. I was aware of the very poor chargers that they do and would never have recommended them. Sav in this forum is the only person I know of who's used a Batteryspace cellpack, the 24 volt 10 Ah, and his have been ok, but as the saying goes, one swallow etc. In addition to what you've said, Batteryspace prices have risen the most as a result of the world nickel prices, and they could be taking advantage of that. Powacycle's price hasn't changed at all.

 

[Baboonking]

just noticed ebikes.ca is no longer selling there stuff outside their state in Canada . Big loss to the electric bike world. I hope they change their mind someday.

 

[allotmenteer]

Looks like Powacycle is the place to go then. I've recently purchased an 8Ah Nimh from them and so far am well pleased with it. It outperforms my 6.8Ah li-ion far more than one would expect from the fairly small difference in capacity. Perhaps my li-ion is actually a smaller capacity. Anyway, it is early days yet and I've only done about 5 cycles of the Powacycle battery so I'll report on it in more detail in a few weeks.

My battery from Powacycle arrived in less than 24 hours! Also the lady on the phone provided excellent customer service and advice and was keen to ensure that the battery was suited to my needs. I was very impressed by them indeed.

Paul

 

[flecc]

The same sort of service I've received twice Paul, Powacycle getting 5 stars from me too.

Your battery's capacity should continually increase slowly until a peak at about the one hundreth charge, the usual NiMh pattern.

 

[Ian]

Does anyone know, and I suspect Flecc may, if the Powacycle batteries are easy to dismantle in order to canibalise the cells without damage, and if they are standard D size. I'm thinking ahead to when my Ezee batteries begin to fail, obviously it would take three 24V batteries to recell two 36V but even so at current prices it seems to be a cost effective solution.

I just hope it remains profitable for Powacyle to supply their own batteries to owners of other bikes.

Ian.

 

[allotmenteer]

Hello Ian

I'm afraid I haven't opened the case as yet (and don't plan to). I'm following Grandad's modification and will be getting a couple of 2 pin american plugs to make up a suitable connector to avoid having to open the battery up and tinker with it.

I'm sure Powacycle have no qualms about selling the batteries to owners of other bikes, it's extra revenue for them. It's better for them if they can avoid having batteries in stock for too long and suffering ageing issues.

If you do buy two packs to recell your 36V system then I'm sure you could sell the ten leftovers either here or on ebay.

Paul

 

[flecc]

Removing Powacycle cellpacks

Yes, it's so easy I didn't even bother to specify how on my Twist site Ian.

It's just the case screws, lift our the cellpack and disconnect the wires, there's no special meter strips incorporated as with the Giant battery.

However, they are no good to you like that, you'll have to cut through all the inter cell connection strips, since the Powacycle packs are conventional side by side cells, and the eZee battery in five columns each of six cells.

My plan when the time comes is also to use the Powacycle packs, cut as described, solder the cut strip ends together and fold them with insulation to create those vertical columns. Having not done it though, there may not be enough available height to accommodate a column made like this, so one will have to be assembled to check the height first.

I may even experiment with using side by side structure instead and slightly lengthening the battery case to suit, using a cut and gusset method.

P.S. The eZee battery was only £150 for nearly all it's life and only went to £175 for the rise in nickel prices. We may see it's return as it has value for marketing budget end bikes, so we might not need to do any recelling.
.

 

[Grandad]

John
I haven't been ignoring you, I just wanted to let others give their views first and I agree with their comments. The battery F size pack you mention would appear to be about one third larger and heavier than a D size pack. A big lump to lug around, nice for a trike though.

Paul
If you use the simpler method of connecting using the two plugs screwed together, I recommend soldering a piece of wire across the two unused pins so that it is more obvious which way the plug goes in.

Ian
I, like flecc (he gives full instructions), have opened up the Salisbury pack, very easy to dismantle but don't do it on a metal bench or leave metal tools around it in case of short circuiting any cells. (Unless it's the 5th November )
Jeff

 

[allotmenteer]

John
Paul
If you use the simpler method of connecting using the two plugs screwed together, I recommend soldering a piece of wire across the two unused pins so that it is more obvious which way the plug goes in.

Jeff

Thanks for the tip Jeff and thanks for the clever connector solution in the first place.

Paul

 

[Ian]

Thanks for the answers Flecc & Paul, I have in the past re-celled an Ezee battery with salvaged side-by-side cells, and as Flecc suspects did find the only way to squeeze the cells in was to completely remove the joining strips and rely on pressure for a good contact, it wasn't an easy job to come up with an arrangement to maintain that pressure.

I agree that the Ezee NiMh battery was good value at £150 (And not bad at £175), I did buy one a couple of months ago but they only had 2 in stock and there was much uncertainty whether there would be any more. As I'm not keen on the Lithium alternative I'd love to see it's return.

Ian.

 

[Ian]

Ian
I, like flecc (he gives full instructions), have opened up the Salisbury pack, very easy to dismantle but don't do it on a metal bench or leave metal tools around it in case of short circuiting any cells. (Unless it's the 5th November )
Jeff

Thanks for the safety reminder Jeff, I'm sure some of us have found how easy it is to weld cells together - without using a welder. I've done it, despite being fully aware of the dangers.

 

[JohnInStockie]

Info for a novice . . .

When you say 'D' cells, are these the same size as the standard battery D cells that you can buy for door chimes etc? Are they the same batteries just wired differently, and NiMh?

 

[Ian]

Info for a novice . . .

When you say 'D' cells, are these the same size as the standard battery D cells that you can buy for door chimes etc? Are they the same batteries just wired differently, and NiMh?

Yes John, they are the same size as domestic D cells and there's 20 in a 24V battery and 30 in a 36V battery .When made up into permanent battery packs they normally have metal strips spot welded to the top and bottom to join them, and every other cell is upside down so the positive on one cell is joined to the negative of the next etc. The arrangement of the cells used in the Ezee batteries is different, but the cells are of the same type and the principle is the same. Lithium batteries are however totally different.

Ian.

 

[flecc]

Anyone interested can see the innards of an eZee Li-ion battery here on my Torq Talk website,

and the common side by side D cell NiMh pack here on my Twist site, showing the connector strips and upside down cells that Ian mentions.
.