Yamaha Easy Advice

[covehithe]

I have been left a Yamaha Easy bike by a friend who passed away recently.
I know it was purchased in 1999 and had a new battery in 2004 which is on the bike.
It has not been used for past 18 months but when I turned in on I managed to get 2 miles on existing charge and the Shimano Nexus gears where really smooth.
It is complete with charger which has a label saying use the "Refresh" button every 2 months. There is no handbook/manual so I am following the label instructions.
The main problem with it is the key to remove the battery has been lost.
Any ideas as to the lifespan of a NI-MH battery (It would have been used as I intend to use it - 5 mile round trip on flat).

Peter

 

[flecc]

Usual life Peter is about 400 full charges for useful range. They don't decline badly with age in the way lithium batteries do, but the range shortens with charge increases from about the 100th charge onwards. It's possible to use them way beyond the nominal 400 charges but with range getting ever shorter until no longer useful.

The refresh is to occasionally completely empty before recharging to ensure the capacity is maintained as high as possible.

 

[piotrmacheta]

Another thing worth noting is that if a NiMH (or NiCd) battery has not been used for a while it needs a few 'use cycles' to get its capacity back up again. I found that 5 charges and discharges to empty did the trick.

 

[covehithe]

flecc

That's very useful to know as I was expecting a much shorter life span. I am going to finally retire early next year and had intended to buy a new electric bike. I shall probably keep this one and see how I get on as I am having knee problems and usual ailments you get at 70+

 

[covehithe]

piotrmacheta

Can the 5 charge/discharges be done by the battery charger using "refresh"mode ???

 

[piotrmacheta]

It sounds like the charger can do that so yes. What I have done is to charge the battery and do a local ride until it is flat (usually not far) then charge fully and then use the battery for my normal trips but carry a spare so that when it runs out you can swap to the spare and do this until I get consistent range (I use an Ahr meter). Importantly don't over-discharge the battery, 1V per cell min is about right so when performance is poor then stop and recharge.