Just bought a 2013. Fine for now, looking into battery options

[ToledoFocus2013]

The son hit some ice and broke his 2003 ICE Ford Taurus. A dealer nearby had a 2013 FFE with 9K miles for $7K and we jumped at it. Everything is running great. Love the car.

I didn't do my research beforehand and didn't know about the coolant leak that plagues these. I am trying to wrap my head around it now so when it does come up, we have a plan. Or better yet, what we can do to mitigate/prevent the damage.

I'm hearing you can bypass the coolant in the pack. Downside being you lose the coolant in the pack of course. Increasing the odds of pack failure for what MAY be an otherwise healthy pack.

What about doing something with the drain plugs? So if coolant does start leaking, it doesn't soak the pack. Or a moisture sensor, presumably inside the pack? We catch that the fluid is low, know that there is a problem, and bypass then?

Buying a remanufactured pack from the dealer seems a no-go due to price. I've found this:

https://enerz.us/products/2012-2017-ford-focus-hybrid-battery-lower-high-voltage

Which seems reasonable, and members here have used them before and it went okay I think.

How about rebuilding the pack myself (where to get the cells?) or (crazier idea maybe) adding a totally different battery in place of it. I saw some threads where someone added extra capacity by wiring up a different pack in parallel. Same idea I suppose, but with a "dead" OEM pack? Probably need a separate BMS, but otherwise straight-forward?

I'm no mechanic nor an engineer (PhD in physics, so I get the basics of what is going on in there). I have rebuilt my own car, pretty much every single part. 1997 Honda Prelude I've had as an only vehicle since 2001. This is a bit out of my wheelhouse, but I am comfortable working with high voltage and taking things apart.

Thanks a lot for any advice!

 

[davideos]

I've replaced contactors 2 times now. I have a newer battery that is less prone for the coolant issue. I like your idea of removing the plugs and monitoring for coolant. I'm not sure if that would prevent an issue, but at least it might give you early detection if it does occur. Although the issue is more likely on the upper / rear pack, I have seen reports of the problem on the lower pack as well. There are drain plugs on that battery too. I was concerned that the plugs were in there for a reason, but recently, I had to replace the contactors on my lower battery and one of the plugs was already gone. I suppose as long as you don't drive in flooded waters, you'll be fine with that approach. And then hopefully, if you catch the issue early, it will not have done any damage to your battery.

 

[ToledoFocus2013]

Thanks for the feedback. I've been going down the rabbit hole of building my own battery for when the time comes. Lot's of useful info on here. Unfortunately all the discussions are years old at this point.

In the meantime, I do think I will at least pull the drain plugs so the coolant can run out if/when the leak happens. I should notice the puddle where it's parked and the car will probably throw some codes I suspect.

 

[Heima]

I am thinking that pulling those plugs might get you an SSN from an isolation fault. If moist air gets into the battery, you will most likely get an isolation fault. Then you would be in the same situation as if you didn't pull the plugs and there was a coolant leak. The HV batteries are sealed intentionally. You might want to consider running a vinyl tube from one drain hole to the other, this way, the system is still sealed, but you could see coolant in the tube.

 

[ToledoFocus2013]

Good to know. I like that idea a lot. I will have to get under there some time and see how easy the plugs are to access then run an air-tight clear tube.

The car has been running great and the guess-o-meter is at 70+ miles. It's our first electric in the household and we all love it. I think we are good shape for a while. Just trying to plan ahead