08 400 ho

[RichH]

Hey 1of7627. I have 2 08 400 ho's (my wife's and my buddy is buying mine). wondering if you have run into this/ about a year and a half ago we went to go riding and my wife's battery was dead, it would pull-start right up and idle fine/ if you tried to give it ANY throttle it would start missing and die/ the battery would not take a charge. put in a new battery-problem gone. Yesterday some friends and I went on a ride / my 400 started right up/ loaded on the trailer/ started right up in the hills and we rode for approx. 8 miles , we stopped for a break/ my buddy went to fire up and go and the battery was dead/ pull-start right up and will only idle. my question is why will it idle fine, but not be able to rev any higher/ the charging system is working great? Rich.

[RichH]

or if anyone else has input it would be greatly appreciated. it wasn't very reassuring to him to have the machine he is buying towed out by my X2.

[1of7627]

RichH, please keep in mind that this is my opinion and I have no science to back it up. I spent the better part of an hour scouring the internet trying to find something substantial, but authoritative references for dead AGM batteries (that the '08 to '10 400HO come with from the factory) are not near as deep as those for common lead/acid batteries.

My contention is that this behavior is more characteristic of a dead AGM battery and not representative of the machine itself. The reason I say this is that I've experienced the same thing (idle, but no higher) on one of my machines where the OEM battery failed and have a friend with another (non-Polaris) machine that had switched to an AGM battery and experienced the same problem when it failed (after less than three years). I know that these machines need batteries in place to run, even if they're dead. But the characteristics of dead batteries in electrical circuits must vary significantly between the various types of batteries commonly in service. I know that a dead lead/acid battery that has been cooked dry behaves differently in a circuit than one that's full, but fully sulphated from being discharge a long period of time. And anomolies related to these conditions vary too. So, my contention is that the machine is fine and the behavior you experienced is "likely or at least possible" in the event of an AGM battery failure due to the charging system not being able to provide enough power for normal operation while overcoming the overhead of the dead battery. I'll keep looking and if I can find an authoritative reference or explanation, I'll post a followup. - MarkC

PS - I do my best to keep my batteries from getting below the recommended 60% discharge state with a year-round battery maintainer. I've always advocated carrying a spare battery in the motorhome on camping weekends and a dry lead/acid battery (new, in the box) could be up and running in minutes. The AGM I carry now is a bit more of a bother as I have to keep it charged and ready, even though I know it won't leak.

Edit: And it's great to have an '08 with a recoil starter! (I retrofitted my '09.)

[RichH]

MarkC I really appreciate you getting back with your thoughts. I agree I don't believe the problem is with the machine. my wife's runs great. I do rotate the Battery Tender from the 550 x2 to both of the 400's , and the one that just died was fully charged when we left for our ride. Thanks again. Rich.