I've killed my motorbike battery haven't I?

[swee'pea99]

My bike's been lying idle for a year or so, and I wasn't that surprised to find that when I pressed the starter button nothing happened. So I took the battery out, cleaned up all the contacts, stuck it on the battery charger for a few hours, then put it back in and....that rat-a-tat-a-rat-a-tat you get when the battery's too low. I was a bit surprised, because the battery was almost new when the bike went into hibernation. (It's one of those gel ones, if that makes a difference.)

Googling around, I've discovered that it's a Very Bad Idea to use a car charger with a bike battery. Have I 'fried the plates', as one poster put it? It's a completely sealed unit, so I guess there's not a lot I can do either way. Just wondered if any of you occasionally-powered bikers might have any ideas.

 

[EltonFrog]

I think you've got get a new battery, not that it helps now, but my wife's bike and my bike are on trickle chargers throughout the winter months, they maintain the batteries and keep em fresh. The bikes start up every time.

 

[vernon]

I use a small trickle charger to revive my battery. As I'm a very low mileage motorcyclist - 2,000 miles in eight years I'm amazed that my replacement battery has lasted five years.

 

[Wobblers]

Possibly not.

After a year, your battery will probably be sulphated. If you're lucky, you might be able to recover it by leaving it on charge for 2 to 3 days. It's best to use a regulated trickle charger or bench power supply set to 14 V for this. A basic car battery charger will put out well over 15 V, but applying a high charge voltage is one way to recover a sulphated battery, so you just might get away with it...

 

[swee'pea99]

Thanks. I'll try putting it on 'permanent float' for a few days, see what happens. It's not like I have a lot to lose.

 

[Maz]

Why is it a bad idea to connect a motorbike battery to a car charger?

 

[green1]

Why is it a bad idea to connect a motorbike battery to a car charger?

Higher current.

 

[Maz]

Higher current.

I see. Thanks, green1.

 

[compo]

Periodically Lidl do a trickle charger for about a tenner that works the same as the Oxford Optimiser, which is £50 +. I used to just connect the charger up to my bike and it would trickle charge whenever the battery voltage dropped to a preset level. Just fit it and forget and come back a few months later to a perfectly charged battery. It can also recover a battery that is dead as long as not too dead, if you get my meaning!

 

[Maz]

When a vehicle (car or motorbike) is left parked up for a long time, why does the battery go flat?
What is draining the charge, apart from, maybe, a clock?

 

[biggs682]

slow trickle charge should be ok

 

[Davidc]

Sealed lead acid should be charged with a charger designed for them. They don't respond well to overcharging, which a crude, cheap car charger will do. Such devices are available from places like CPC, Farnell, RS and likely on ebay.

Most modern sealed lead acid batteries are designed to recover from deep discharge, but my experience with several has been that they only do so with several charge/ discharge cycles.

 

[yello]

Most modern sealed lead acid batteries are designed to recover from deep discharge, but my experience with several has been that they only do so with several charge/ discharge cycles.

That's my experience too. I've been able to recover both mine and my wife's bike batteries from deep discharge; sometimes with just one recharge, sometimes it takes a few attempts, But on one occasion, it was irrecoverably gone and I had to buy another.

Both bikes are usually on trickle charge over periods of intended non-use but sometimes, well, time just passes and you don't realise it

 

[Firestorm]

Both my bikes are kept on Optimates seems to prolong thr battery life in the winter layup

 

[Profpointy]

My guess is the problem was leaving it go flat for a year. lead acid batteries don't like being stored flat, and they go flat over time. i very much doubt if charging it up "wrongly" afterwards has mad it any worse. Whilst you dont't want to over charge a battery, bear in mind it is designed to delivery maybe a hundred amps or so when starting the bike, so I doubt if charging it at 5 amps or whatever's really an issue. At any rate, i've chqrged bike batteries with a car charger before now. You can also get "fast chargers" which put a fair bit of welly though with no harm - providing not left to cook for days.

But leaving it stand when flat, even for a week or two once it's gone flat = dead battery.