Where to get Batteries

[Sav]

Just an update.

The Panasonic charger failed twice with the new cells so I've deciced to wait for the Flecc charger to arrive fom Yankeeland.

Am not prepared to risk partial Panasonic charges with the new cellpack.

Chris.

 

[Sav]

Finished the first set of runs with the new 10Ah cellpack, up and down to the local Post office, absolutely no flat stuff whatsoever. After 17 miles of lugging this 16 stone pensioner up and down the hill it went down to one light.

I was a little disappointed, but thought ah well its the first charge and its a fairly steep hill, so maybe not so bad.

Just been out to look at the charger and seven hours later its still discharging!!!! guess the battery meter is confused by the new cells, Flecc will no doubt comment.

Looks good!!

Sav

 

[flecc]

I'm sure that's the answer Sav. The meter might improve after two or three more charges and discharges. It was perfectly ok with the 8 Ah Powacycle cells, but it might just be that the 10 Ah ones are beyond the range the original meter circuit can operate with. It was after all designed for 6.5 Ah.

You'll know from the placement of the meter leads on that metal strip that the resistance difference between them is miniscule, so the slightest change, even in lead placement, could upset the measurement.

If it doesn't correct, you should be able to establish the effective range by trial and error though, and thereafter use the trip recorder on your speedo to judge when it's nearing the end. That's what I do with the eZee bikes since the handlebar meter isn't very accurate.

When all's said and done, 17 miles of that hill climbing with a heavy load isn't bad anyway.
.

 

[Sav]

First report on the Yank batteries after three charging cycles.

Running in rolling downs, so mostly hilly country with virtually no flat stuff. Me @ almost 60 & 16 stone of not very fit condition. Left the control on permanent eco. so no attempt at economy by turning off on the bits of flat stuff.

24.7 miles the handlebar control started warning flashing slowly
26.7 Flashed quicker and cut out soon after.

Got the last bit home under assistance by a couple of off / ons for 27.1 miles.

Think I can say I'm happy with that!!!

Sav.

 

[Flying Kiwi]

Thats very good range (the most I've heard of for a Giant Twist) and I wish I could get mine to go that far - I haven't even got 20 miles out of my 6.5 Ah battery Unfortunately it's quite hilly around here though and that makes a big difference.

 

[flecc]

That's good Sav, given the circumstances right on spec for those 10 Ah cells. For an average weight person in moderate country they might well do the 30 miles theory predicted.

 

[Sav]

For an average weight person in moderate country they might well do the 30 miles theory predicted.

Hmmmmmmmmmmmmmmm!!!!

Yup, I'm pleased with that. Would have settled for 25.

The battery indicator is still reading too low on the new cells, but its not a problem with a trip meter and may sort itself.

Sav

 

[flecc]

The battery indicator is still reading too low on the new cells, but its not a problem with a trip meter and may sort itself.

Sav

As previously said, I think the 10 Ah cells may just be beyond the design's capabilities. At the time of the design with 6.5 Ah they probably wouldn't have been considering this scale of increase.

 

[Flying Kiwi]

The battery indicator is still reading too low on the new cells,

I wonder if that means that people should ensure the indicator display is always connected to a 24 volt source at all times when changing over the cell pack? ie the old pack should only be disconnected from the indicator circuitry after the new pack has already been connected. I'll be interested to know if it does eventually settle down correctly Sav. Will you please post an update again after a further 10 or so discharge cycles. Thanks for the progress report so far.

 

[flecc]

I wonder if that means that people should ensure the indicator display is always connected to a 24 volt source at all times when changing over the cell pack? ie the old pack should only be disconnected from the indicator circuitry after the new pack has already been connected. I'll be interested to know if it does eventually settle down correctly Sav. Will you please post an update again after a further 10 or so discharge cycles. Thanks for the progress report so far.

There's nothing in the meter circuit to cause that to be necessary, it's a fairly straightforward use of a ladder IC which I've personally used in the design of mains power interference meters. I think the problem is the critical separation of the points of connection to the meter circuit on the strip attached to one end of the cellpack, the resistance differential being miniscule. The strip is illustrated below at (1) and the two wires attached to it, and their separation, can be seen. The meter was perfectly ok after a single charge/discharge with the 8 Ah Powacycle cellpack, but the high density electrolyte in those 10 Ah hour cells that Sav used will alter the overall resistance relationships in the meter circuit. I can't say if my re-cell will always meter correctly, since cell resistance increases over time and mine may move outside the acceptable limits.

 

[allotmenteer]

Done a bit of research, without wishing to tread on Flecc's toes for his excellent work.

Found this and have put a piccie on one of my sites.

24v battery pack

Chris.

It seems that there has been a big price hike on the nimh batteries from batteryspace.com. The battery above is now $249.95 (up from $168.95 - nearly a 50% increase!). This makes the powacycle packs a real bargain - get 'em quick!