It's not a cure. But it may help lessen the symptoms to do a very high charge. Getting to 100% is difficult without special equipment. But getting to 80 - 85% is pretty straight forward. If you have a really long hill, like going from the continental divide down to Denver, the car will regen up to 80-85%. Live in an area without mountains? And you need MOUNTAINS not hills where you can go downhill for 30 minutes or more... you can do this, and I'm surprised not more people think of this.... have someone tow you with the car on and in "L" position. You can also ride the brake pedal really lightly or depress for a few seconds, release for a few seconds: repeat. A lot. For like 30 minutes 15 to 30 miles.

Regen power (kilowatts in of charge rate) will get less and less the higher you go. It may even go to zero for a short time to let the battery "rest". But it will come back on.

This the the easiest, cheapest, and least technical way to recharge you battery without any special tools or knowledge. Just tow safely. You don't need to tow fast. 25-30 mph may do it. But I've done it descending the rockies on I70 a few times at 50-60 mph.

Safest and in some states it is a legal requirement to have a solid connection to the towing vehicle - that is use a hitch or tow bar, do not use rope or chain. If the lead vehicle hits the brakes or needs to stop, you want to make sure your FEH stops IN ALL CASES. Panic stop or not. I guess you could also be pushed for 15 to 30 miles. Plus dragging chains cause sparks and wild fires.

A super charge (way above the nominal 53%) will do a good deal of cell balancing. You should know right away (first time) if it helped or not. If it made no change, no need to repeat the process.

P.S. It's been said 100 times but I'm going to say it again. Any hybrid over 10 years old needs to be started and ran EVERY SINGLE DAY to stay healthy. Sitting is the worst thing for the battery. You only need to start it and let it idle until it drops into EV mode. You don't have to drive it. You can do this in your driveway. Leaving town? Pay some high school kid or next door neighbor to come run your car for 4-8 minutes a day. Use the same person feeding your pets or watering your yard or collecting your mail while you are away. Or loan the car to a trustworthy friend or relative and let them drive it while you are away.

My wife and I used the 2005 FEH daily and never had an ounce of trouble for 15 years. MPG was the same as day one and EV range (1 mile on flat roads) was the same as day one 15 years later. Then it got rear-ended by a distracted driver. Our 2005 FEH one of the first 10,000 made never died. It was killed. I had another make of hybrid that I let sit for weeks and the battery self discharged many times. I was able to force charge it and revive it about 100 times but it was not a Ford. But also had NiMH cells.

 

I'm 100% certain that operating a FEH with compromised A/C where the battery exceeds 100°F, which is plenty easy at 95°, the battery is rapidly damaged. The FEH and HCHII use the exact same cells in their packs. The HCHII is notorious for horrific battery life while the FEH is among the best. The difference is cooling. HCHII cooling system is complete garbage. FEH uses a rear evap to cool the battery even when cabin A/C is off. These cells are completely intolerant of heat.

 

Do you have any quantitative data that demonstrates an improvement following this treatment?

I can tell you getting a Prius to 80% to 85% is child's play, and it makes NO difference whatsoever. NiMH is self-balancing when healthy. Improvements may be had at 100% SoC due to oxygen evolution at the terminal and an alteration of phase restoring the "good" chemistry, but this usually requires deep discharge to less than 1V/cell PRIOR to running to 100%.

 

Agree. I noticed at about 8 years of age our FEH was getting hotter and hotter with normal use as the internal resistance grew. Toward the 14th year it was running the AC to chill the pack on 50 degree days. And this was grocery getting on like 20 minute / 15 mile drives. It becomes progressively worse with age. Not having active cooling will be a death sentence to these packs at 10 years +.

 

1. The Autel Maxisys MS906 has that functionality.

 

You're not balancing packs with anything the stock BCM is capable of doing so this is a waste of time.

 

Who are you talking to, and about what?