Morning krew,

Feeling the fool this morning...
Must have been a bit tipsy when I finally lowered the shed door and said good night to my K100 12 months ago and set off to Tasmania on my Yamaha. 

It seems that Ive neglected to disconnect my battery! 

Its an expensive Deka AGM, very very good battery...but I fear Ive buggered it....
Its only reading 6v! 
Also, my 3 stage charger seems to have died in my absence...So my dilema....In the short term, do I fork out the cash for a nice new charger with the aim of restoring my lovely battery, or would it be cactus and my hard earned is better spent on a new battery?

I would guess that your battery may not be able to come back to a useful life. Once it goes that low, you may as well lower it into a grave, it is dead.

ainsjac wrote:I would guess that your battery may not be able to come back to a useful life. Once it goes that low, you may as well lower it into a grave, it is dead.

Yeah I thought as much....wont make that expensive mistake again....

As far as your charger goes, it may be that the charger is of the type that needs a certain level of volts from the dead battery for it to turn on.  I would check the charger on another battery before I decided it was bad.

Before writing off the battery, see if someone you know has a desulphating charger you can try. These are newer chargers with a mode that jolts the battery with reverse current to destroy sulphate deposits that may have formed and shorted the plates due to the neglect. Don't know if AGM batteries respond to this treatment however.

kioolt wrote:As far as your charger goes, it may be that the charger is of the type that needs a certain level of volts from the dead battery for it to turn on.  I would check the charger on another battery before I decided it was bad.

Agreed, a lot of "smart" chargers won't try and charge a dead flat battery. Try the charger on a known good charger before giving up on it.

You may be able to get the AGM battery to start charging with a simple charger.

Richard.

Floyd I'm at North Lakes and have a really  good charger if you want to borrow one. A trickle charger will not resurrect a really low battery.
Regards Martin.

MartinW wrote:Floyd I'm at North Lakes and have a really  good charger if you want to borrow one. A trickle charger will not resurrect a really low battery.
Regards Martin.

That would be brilliant mate. Worth a shot at the least.

Ill PM you now.

kioolt wrote:As far as your charger goes, it may be that the charger is of the type that needs a certain level of volts from the dead battery for it to turn on.  I would check the charger on another battery before I decided it was bad.

+1 on that.

I put a Motobatt in the RT (which has a habit of killing batteries).  Anyway, long story short, she went very flat after the bike not being used for a little while.  I put it on my Ctek charger and all it showed was 'faulty' after trying for a day or two.  I bit the bullet and ordered a replacement (my favourite Panasonic 28AH).  Thats all good.

I then decided to try my less advanced 10A charger on the Motobatt and guess what, it came back to life after just having amps thrown at it in an uncontrolled manner.  I then did the Ctek recon(desulphate) mode on it and the Motobatt is now holding a steady voltage.

So it's now a spare battery, not 6 months old that has had the life sucked out of it once and now revived. I still have to find a use for it at this stage.

Al

good result Al
those smart things are not always the best for all situations
nothing like brut force and ignorance ....sometimes

Sometimes if you connect the charger to two batteries at the same time the weaker one will kick back in after a while. Think of a 5 volt and a 13 volt battery together, the charger will see them as one 9 volt and work.

For what its worth that happened my son who has nice expensive digital chargers and gadgets. No way could he get it to charge. They all seem to need some initial voltage or something.

So I suggested he take my 20 year old 'analog' charger and try it on the basis there was nothing to lose. So he did, the charge light came on we left it to charge. It worked, so worth a try. He had bought a replacement which I told him to take back. The credit note bought me new bike boots so happy all round!!

Thanks Martin! Your charger has saved me $230

The generosity of this forum constantly wows me.

Battery is now holding 12.8v and my own charger is not broken, as some suggested above...It was advertised as being able to charge a dead flat battery, but I guess not....

A trick I've used successfully over the years on 12V batteries that have some life left in them, is when a battery has dropped to less than 6V and your 'trickle charger' won't start charging due to the voltage being too low - itself a safety feature for hamfists who attach the leads in reverse polarity - attach an old-fashioned 6V charger and if the battery accepts the charge - because it's not too flat - bring it up to 7V or so, then connect your 12V charger. The 12V charger will probably now 'recognise' the battery and take it up to the proper 12V+ static voltage.

Of course, if she's done she's done and often no amount of attempts at charging will resurrect it.

Big Red triumphs again, I use it when I want to scare batteries into submission. I have a smart trickle charger screwed to my garage ceiling it runs off the roller door supply. I've had two Deka batteries first did 8 years the second did 5 years. They did not have one in stock the last time so I used the one they recommended Rev Plus
High performance which has been going for 6 years.
Regards Martin.

Had a look and got the battery number of the Rev Plus battery SVT 2. I tried to look it up and I can't seem to find it.
Looks like they no longer make it.
Regards Martin.