Im sorry if this seems like a dumb and simple question but here it goes regarding the H6-H7-H8 batteries its my understanding the H6 and H7 batteries are acceptable to interchange however the H8 battery is not? Its the same dimensions as the H7 only a little longer my H7 AGM puts out 1000CCA with 850CA my vehicle on parts checkers like autozone and oreillys it is listed that i need an H8 however i have a nearly new H7 AGM purchased roughly 6 months ago with the aforementioned 1000cca 850ca is this H7 battery okay to use? Will my XJR require the H8? Aside from the cold cranking amps and cranking amps? And can anyone tell me what the car’s electrical system expects? Sorry im confused in looking into this thank you ☺️

 

Get a 49H8 lead acid battery. It’s designed for those big ol batteries. A T40 Torx is needed for the hold down bar. If the threads look crusty, clean it up and use anti-seize or an oil.

 

I absolutely would and will given i had the money lol so between waiting for the money to get the new battery and now is the H7 acceptable as a battery for the car? Also wouldnt it benefit from an acid glass mat? And lastly why would parts checker not even say H7 is a workable battery? Sorry i am a tad ignorant on batteries

 

Your H7 AGM is an excellent choice.

 

AGM works very well with these cars. The only issue is that if you ever need to charge it, you need
a compatible agm battery charger.

 

I can’t speak from experience about the AGM batteries in these cars. I seem to recall a few posts about there being a “battery not charging” being displayed on the IP due to AGM battery being used. If Randy & RJ have them and they have no issues, then I’d say go for it.