MTP-91 - needs spacer. Best buy.



MTP-H6 - no spacer required and looks like the OEM battery.

 

Shopped at Sam's Club yesterday and they have Interstate 91's for $87.77 plus I have a $10. discount card from some promo. Makes the total bill about $83. tax incl. for a new Megatron. Just had my '04 inspected and had Firestone test the Varta and they said it had about one third CCA of original spec. They also wanted $173. for an H6 . I know they want to sell batteries but I think I'll replace it at Sam's before another Texas summer for $83 Oreilly's wanted $91+tax for their brand.

 

Thank you for FINALLY answering the question. I now understand that the original, correct battery is a lead acid battery. AGM requires slightly different charging technology as I just found out. I bought an '06 roadster a few months ago that the previous owner put an AGM in that was manufactured just 9 months ago. It's toast because the Xfire charging system's not set up for it.

 

The post before yours was 12 years ago, he must have had a premonition you were going to ask it.

 

I have three Crossfires, they all have AGM batteries that are 2 to 3 years old. All three cars start and function just fine.

 

Yes, I was aware of the age of what I was replying to. My reply was not about the age but about how far down the thread it was before there was an answer to the question. I had been searching for the info. It's frustrating sometimes to find that someone has asked the question I have and then have to search, often in vain, for an answer somewhere. Regarding my AGM battery, for some reason it lost its charge. Advance Auto Parts charged it and found it to be good. I reinstalled it in my '06 roadster (17K miles on it) and it started, the spoiler went back down, the windows worked, and all seems fine...for now. Losing the charge caused the spoiler to raise. What caused the battery to lose its charge is a mystery at this point, especially with it being manufactured only 9 months ago. The alternator appears to be working, so further investigation is warranted. We'll see. I ordered a Schumacher SC1281 battery charger today since the one I have is about 40 years old and meant only for older lead acid batteries. The SC1281 will hopefully help keep the AGM battery healthy and also diagnose possible alternator problems. Keeping my fingers crossed. I have 3 Crossfires ('05 roadster, '06 roadster, '07 coupe) and have been bringing my knowledge to an appropriate level from the relative stone ages.

 

How long have you owned it? A known cause of battery drain is old batteries inside the alarm siren leaking acid and shorting out.

 

I agree. Forget about weight. Go with an AGM battery. These cars are known for draining batteries if left to sit too long like any modern car these days. The XF was just before its time on parasitic battery drain so it shocks some people. I went with a Diehard Platinum AGM. Not cheap but also no worries about letting it sit for a while and having a no-start situation. I also have a rapid disconnect on the battery so if it is going to sit for more than a week I can easily disconnect it with a few quick twists. I haven't pushed this battery to the breaking point so I've no idea how long it could last hooked up without being driven but I don't want to do that. Drain a battery that far and it never comes back to full storage capacity... do it a few times and the battery is junk in these cars.

 

.


The tried and true 'wet cell' is the preferred choice. All the other options are personal choices & solutions for a variety of issues not associated with the end results of starting the car and its short-term (only) storage. Remember, the storage of a car requires you to disconnect the battery, so its OEM sized battery is the choice that most makes sense (especially for the cost associated with its purchase). Spills, storage, and options added into the electrical system are all grouped into the 'what do I do about' isms. Good luck!


.