light flashes when on charge

 

You might want to expand on this statement a little. Also MY would help along with the age of the battery and other symptoms. .

 

Battery is 2 year old AMG. Car is completely dead, FOB doesn't work. On slow charge warring lights flash during charge and finally after 8 hours charger ends up in maintain mode with a solid red light. Still car is completely dead.

 

What is the voltage at the battery. Are you charging with a 10 amp or larger charger . What year is the car . If a 10 amp charger doesn't charge the battery you would need to pull it and have it load tested.

 

Just because an AGM battery is only two years old doesn't mean it's still good.

Kindly provide more information such as MY, current kilometres/miles. Has any other work been done to the vehicle recently?

 

I was using a 2 amp charger. Just put 10 amp charger on and it goes back and forth from charging to fully charged. I don't have a meter to test voltage but something is draining the battery. Break light and front yellow lights stay on can't shut them off. It's a 2007 XK. Could it be something other than the battery? Battery in the FOB is only 6 months old and that's not working.

 

Unhook the car from the battery while trying to charge it. You're trying to fill the tub with a trickle of water and the drain is still open.

 

Agree here and if there are lights on without the ign. then he has a something else going on. Also a 2 amp charger won't hack it.

 

Remove the battery from the vehicle and have it tested by someone with the proper equipment.

What is the voltage across the terminals with the charger removed?

 

I've disconnected from car and its charging now. I thought it would jump to full charge shortly but its not. If it wont charge I'll pull it and have it tested or replaced. If it charges and car still wont start I'll let you know. Thanks for the advice.

 

On the Xk there's just too much 'stuff' that's in standby mode all the time waiting to be woken up by the can bus. When the bus voltage drops from a weak / dying battery the 'stuff' think it's being woken up, powers itself up and finishes the job killing the battery. Once you get over the thresh hold where the battery is acting like a shock absorber and keeping the voltage stable the 'stuff' will stay asleep while the charger finishes the job.

On mine the auto lights, auto wipers, HVAC and the alarm would all try to power up on a dead battery. It was a challenge understanding what was going on. Only fix was to pull the cable and charge the battery up.

 

I appreciate all the advise you guys and this site are great. Thank you
p s its still charging

 

It may well take a long time as it sounds to have suffered.

 

Your absolutely right, there's so much being powered up that you have to disconnect the battery to charge it. Everything is working fine now. Thanks again

 

I definitely suggest having that battery load tested. You probably don't have a deep cycle battery, so the charging and discharging it went through could have easily damaged it. That's true even if it was fine before all the charging.

 

Possible, but if so, zoeooe will be the first on this forum to claim a failed AGM battery...

 

I believe if you use the search function on the forum you will find there have been others with failed AGM batteries.

 

My new Bosch AGM failed after four months. Obviously it was covered under full warranty, but it would not hold a charge.

By way of comparison, I had an Optima Red Top AGM last for nearly 11 years in a car that was infrequently driven. That battery was always disconnected when stored.

 

Unfortunate... Did you get a direct replacement? Is this in the XK or XK8?
Battery part number?

(Who makes Bosch batteries BTW?)

 

It was the new (to me) XKR. During the sale, after previous owner and I agreed on price, he garaged the car. Two weeks later getting ready for transaction, the battery was dead. Owner put new battery in as opposed to recharging old one. Good example of how being a member here helped me understand that batteries in X150's are known issues and that there was nothing wrong with the car and I should proceed with the sale.

Bosch makes the Battery. Premium Battery Part #: 49-850BAGM. And yes, direct replacement, although I had to pull the battery and swap at the store. Heavy MF indeed.