Hi all,
I hope you are doing well. So I bought a Ford Escape hybrid 2008 with 93,000 miles in August 2022. The car looked to be in great condition, and I have really enjoyed it so far. One thing that I noticed 6 months later is that if I don't drive it let's say for like ~ 4 days the hybrid battery was discharging and I get the Stop Safely Now wrench. Yes this has been an issue, but there is the jump button on the driver's side so just pressing it and no problem technically



But now it is fall 2024 and 113,000 total miles, and if I don't drive the car for more than 24 or 48 hours it still requires a jump press from the driver’s side and I still get the Stop Safely Now Wrench indication.



I have tried many things, I have a brand new 12 Volt battery, and I have tried leaving the 12 Volt battery unplugged but it still gives the some issue. I also checked for parasitic draws with a clamp meter and appears to be smaller than 50mA.



I have been debating whether I should change the hybrid battery or not, the car is in really nice condition. I can still press the jump button and just drive it, but I am afraid it might soon be needed very frequently…



These are the errors I'm getting from Forscan (Attached at the end of this message along with some oscilloscope plots).



I do not understand every code, but it seems that the hybrid battery is slowly dying. Pack voltage is 272 V after not driving the car for a little more than 24 hours. Any input would be appreciated and if it is worth it to try to fix it (DIY or not). Thank you in advance.

 

Del_mod_v?

 

So I did two measurements. One was while the SSN wrench was ON and gave DEL_MOD_V =1 V .

Then I pressed the jump button and 8 minutes later DEL_MOD_V dropped below 0.1.

Both pictures attached.

I should also mention, that after starting, the vehicle runs just great. 30 (or more) MPG and goes on EV mode all the time. It is only when it sits for more than 24+ hours that the issues start.

 

Table view is more useful if you're looking for snapshot data.

You have a failed cell or cells that can't hold a charge. The only options are:

1) tear the battery down and test all 50 five cell sticks, identify the failed ones, replace them with sticks that perform similarly to your good ones and rebuild the back.
2) replace the battery.
3) live with it until it gets worse (it will).

 

I see. That is unfortunate, but I appreciate the time. Thank you.

1) Would you happen to know a tear-down thread or youtube video ? I found this one but sure looks like a mess.

Also what is the best way to test battery cells?

2) Would you recommend purchasing a refurbished battery from businesses like GreenTecAuto or the hybrid doctor ?

 

#1 was vague on purpose. DIY efforts rely primarily on luck.

#2 yes.