I have a bike battery that I forgot to hook up to my optimate and now 6 months later it is, well, dead as a can of spam! The problem is that now when I attach the charger/conditioner, it won't even register there is a battery attached and won't start charging it. The battery isn't that old at all - maybe 1.5 years, so before I go out and buy another... Does anyone have any advice on how to resuscitate this one or is it fubar'd?

Cheers
Luke

Do you have a multimeter and can measure the battery voltage.

Funny enough I have near the same question as Luke I have an battery Yuasa packed in the box, brandnew and unused, bought it 6 months ago. How long can an new unused battery stored like this, or will it go flat dead overtime?

My information suggests that the batteries will slowly discharge internally and therefore should be topped-up so as to remain fully charged. You can try charging the battery, you have nothing to loose, but if it recovers at all its performance will probably be significantly less than optimum.

If the charger can not detect your battery and you do not have access to a dumb charger perhaps you can fool the smart charger by placing another good slightly discharged battery in parallel with your flat one. The charger should detect the good battery and provide an output that would also appear across the terminals of the flat battery.

You can buy battery rejuvenating devices (to de-sulphate it), but they're not cheap and they even the manufacturers state they have mixed results.

magg wrote:Do you have a multimeter and can measure the battery voltage.

Yep, and it read 0.4 volts!

Your smart charger will need some convincing that it is a battery and given its current state would not expect much life if any even if you can get it to take a charge. Don't like your chances but as I said you have nothing to loose although I would recommend that you buy a new one.

magg wrote:Your smart charger will need some convincing that it is a battery and given its current state would not expect much life if any even if you can get it to take a charge. Don't like your chances but as I said you have nothing to loose although I would recommend that you buy a new one.

Yeah - I think I'm just going to cut my losses with this one and buy a new one

Just a suggestion for those that, due to weather or work commitments, are forced to leave there bikes unused for weeks at a time, you should float, trickle charge or top-up charge your batteries. Newish batteries probably only need a top-up charge every 3-4 weeks whereas a 2-3 year old battery may need a charge every 2 weeks or sooner. How often to top-up charge can only be gauged by measuring the voltage. Typically a battery with a voltage of less than 10.2 is considered fully discharged but it is preferable not to allow the battery to discharge this far.

magg wrote:Just a suggestion for those that, due to weather or work commitments, are forced to leave there bikes unused for weeks at a time, you should float, trickle charge or top-up charge your batteries. Newish batteries probably only need a top-up charge every 3-4 weeks whereas a 2-3 year old battery may need a charge every 2 weeks or sooner. How often to top-up charge can only be gauged by measuring the voltage. Typically a battery with a voltage of less than 10.2 is considered fully discharged but it is preferable not to allow the battery to discharge this far.

This was in my old racebike. Since switching to the NC30, the 675 got somewhat neglected as I just stripped parts off it to sell and buy new bits for the NC. I meant to chuck the battery on the charger but just kept on forgetting!