Lafree battery meter

[Cyclezee]

I recently bought a 2nd hand 2006 Lafree, in excellent condition, but that is another story.
It was sold to me with the last of the led's flashing continuously, pressing the test button did nothing. Otherwise the battery functions perfectly and I can get 20 miles easily, only problem is not being able to check how much power is left until the red light starts flashing on the handlebar control.

I took the battery apart to have a look, (somebody else had opened it previously as the stickers were split), the black wire going to the sensor from the meter was broken, so I thought aha! sorted, just a case of soldering the free ends together. Couldn't find my soldering iron, so spliced the wires and taped them to see if that would sort it. All led's were now out, no flashing, pressed the test button all lit up and duly went out after a few seconds to show the battery is fully charged.
Problem is now whenever I press the test button it shows a full charge, however many miles I have done!
Any suggestions how I can fix it? Do I need a new meter? If so where can I get one?

Thanks

 

[Ian]

Hello and welcome Aldby.

Battery meters on all makes are notoriously inaccurate and have been the subject of many queries on this forum. The reason for the inaccuracy is that they measure the battery voltage which does not decrease in proportion to the state of charge. Typically the battery voltage will remain constant for about 80% of the charge and then decrease rapidly for the remainder. This means the battery indicator will show a full charge for most of the cycle and then reduce quickly towards the end, no change being seen until less than 20% remains. While this is far from ideal there is simply no accurate way of measuring the remaining charge in the battery which is essentially a chemical rather than electrical device.

It is quite possible that since your repair the meter is working properly but you simply haven't discharged the battery sufficiently to see any change on it.

If the battery meter is indeed faulty I think it is unlikely to be available as a spare part separately from the battery.

 

[Cyclezee]

Hi Ian, thanks for the info. After the repair, I did I rode it for about 10 miles before the power ran out, then did a full refresh charge and have gone another 10 miles morning, all the led's are still lighting up. On the same run my wifes Lafree started the journey with 4 led's light and finished with 2 led's lit. This would suggest that her meter does measure discahare gradually?
John

 

[flecc]

These batteries meters are very sensitive in their operation, and the minutest resistance change will upset them. A twisted connection will definitely upset the operation, as will a connection on the sensor strip remade at a slightly wrong point.

They also often refuse to work after recelling if anything in the operation isn't carried out perfectly in wiring or dimensional terms. I started this recelling of these batteries and have had no trouble, but one of our professional recelling companies now refuses to do the Twist series batteries because they apparently can't get them right. This gives you an idea of how difficult it is to correct one once it's operating incorrectly. Giant will not supply spares in the UK, I suspect the same in the USA, and given the finicky nature of this meter, there'd be no guarantee a replacement would work. The only viable options if you cannot effect a repair are to either to live with it or buy a new battery. In the UK £250, but I'm not sure currently in the USA for you.
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[Cyclezee]

Hi Flecc, do you have spare meter from a pack by any chance ?
By the way I'm in the UK.

Thanks,

Aldby

 

[flecc]

Sorry about the USA mistake Aldby, I've been answering so many US queries on Twist lately I was getting used to it!

No, I don't have a spare case or meter, and in fact they've been in huge demand since so many want an old one to recell as a spare. What with that, those cases which have been accidentally broken, and the fact Giant won't supply them as spares makes them almost impossible to get hold of at present. With my Twist getting less use these days I'd already given my number two battery to another forum member in need.

There are a few Twists getting scrapped though, after their main units fail and the owners refuse to pay £450 for a replacement unit, so it's worth you putting a wanted ad in this site. I think you may get one in due course that way.

I also know of at least one person with a future intention to buy a second hand Twist to take the unit from it for another use. They also will have the battery going spare.
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