2010 Ford Fusion Hybrid ,Regular (under hood) Battery Problem

I purchased this car new in March 2010. I am now on my 4th battery, which have all been replaced under the 3 year warrantee by Ford. The regular underhood batteries go dead between 2,000 to 8,000 miles. I have discussed this situation in detail with Ford and they have a file on it with their Customer Care Team. My conversations with them have been basically a one way conversation. They will not give any insight from their standpoint. To my way of thinking, either Ford has a bad batch of batteries and are replacing bad ones with bad ones, or the battery is not being charged adequately while driving. I asked the dealer to check the charging system and they said it checked ok. I understand that Prius had the same problem and eventually upgraded the batteries to a larger capacity battery. The concept of a hybrid is to save gas by keeping it in UV mode (all electric) as much as possible, which we do. However this means there is more demand on the regular battery since when the gasoline engine is not running the charging system is not operating, therefore possibly running down the regular battery. I was ready to have a battery for a regular non hybrid Fusion installed, which has more capacity, but it won’t fit (too large).
Has anyone else had this problem?


Has anybody bothered to measure parasitic draw?

You don’t need to be a hybrid expert to measure that . . .

There’s some problem not related to the hybrid system. My 2011 is still on the original battery battery.

I bought my Fusion Hybrid in June 2010 and I’m on my 3rd under hood battery. Unfortunately, I’m in a country that doesn’t sell this car, so I’ve had to pay out of pocket. One thing I learned was that the under hood battery needs to have the negative lead disconnected if I’m not going to be driving for more than a week or so. 2 times the under hood battery was ruined when I didn’t drive it for a month or so.

@barnes138 it REALLY sounds like you have a parasitic draw. Can’t you find anybody competent enough to perform a parasitic draw test?

Again, like I said, this isn’t a hybrid specific procedure.

If either of you want to take a stab at finding a parasitic draw on your own, here’s a video that someone made on how to find it:

@98caddy who is “either of you” ?

I for one know how to perform a parasitic draw test, using my Fluke 88 at work.

You are referring to OP, I presume . . .

@db4690 I was referring to both of the previous posters who mentioned their parasitic draw issues - @RCY and @barnes138