Leaderboard

Ford Quick Lane runs specials on the battery all the time. Currently, they have the MOTORCRAFT® TESTED TOUGH® MAX BATTERIES STARTING AT $129.95 MSRP.* plus tax and installation with a 3 year replacement and 100 month prorated warranty. For about $20 installation (2015 price) or so, IMO, it's not worth DIY. They will also test your battery for free. Tire rotation is $10 total. So, I go about 15 minutes before they open, get tires rotated, battery checked, drink a couple cups of coffee and eat two doughnuts all in a little over an hour. Best $10 you can spend (Nov. 2019 pricing). ?

It was time to change mine two Februaries ago when I had to use the key embedded in the FOB twice because the doors wouldn't unlock. I could find the battery slightly cheaper online but then you also have to deal with shipping, plus with no heated garage wrenching on the thing for a half hour in the cold just didn't seem appealing to me. I second the notion of using the Ford service special.

Oops that’s Ford Quick Lane. Yes, you need to try charging overnight to see if it will hold charge and then you can monitor SOC with FORScan. If it holds charge, I’d reset battery age which might get the SOC up. With only 4% SOC, the normal battery drain (up to 50 mA or 0.05 Amps but should be less) when car is off could result in a no start if the car has not been run for several days. The Ford battery is rated 43 Ah when new. So, 4% SOC means the battery capacity is around 1.7 Ah before voltage drops to IIRC 10.5 V which is defined as zero SOC. 1.7 Ah / 0.05 A = 34 hours. The car will likely still start at 10.5 V as modules can still operate at 10.5 V. So, as long as the there’s still enough power in the battery to close the HVB contacts, the car will then start.

Given complexity of changing the battery (it's not just open the hood and get at it...it's in the trunk and you have to deal with a lot of different screws to take apart stuff to get to it) and the fact that it's a fairly rare battery (Costco doesn't have it) I'd just say get a dealer or knowledgeable repair shop to replace it. Why risk finding it dead at the wrong time. Is the gamble worth it? Oh - and you have to 'reset' the battery age correctly for it to live a long life. Do you know who to do that? I replaced the battery after I bought our two used C-Maxs. Worth piece of mind.

My 2013 made it to January on the original factory battery, 7 years, 3 months, with no issues. I no longer own the car, but suspect it's still working fine, unless the car's been sitting. I'd look into the car's history to see where it was in the country. Heat matters. We get great battery life in upstate NY, Plus 3, not so much in AZ. Stay well, Frank

I couldn't resist ?