Main battery icon always empty

Car was losing power and the main battery fan was always running. Many dash lights were on. I measured two weak cells in my main battery so I replaced them with used ones. I carefully soaked all the copper jumper plates in swimming pool muriatic acid and sanded them with fine sandpaper. I installed the main battery. Right away I noticed the battery icon is empty. Car drives normally but that icon never shows any bars. Did I forget to connect a wire?

 

Note the car icon at the top left is full (is it ever not full?) but the battery icon is always EMPTY.

The battery icon used to work fine before I replaced two of the main battery cells. Did I forget to attach some wires?

 

The car now has power and never runs in slow motion like before I replaced those two weak cells. I believe the main battery fan stays off although today it threw the red triangle light and a P0A80 code. Boo hoo.

 

T

Thanks Dave for the thoughts and help. I’m pretty sure the battery indicator and outside temp always worked fine - until I did the cell replacement.

however, my climate screen stopped working 5 years ago and a friend helped me Wet that solder joint which made it work again for 2 years before quitting again. I can still turn on the AC using the steering wheel and set the fan speed by adjusting the set temperature using the steering wheel up and down buttons. It’s really crude.

And last year my entire dash began going dark once a week or so. Even the gas gauge goes dark which makes fuel anxiety a stressful issue.

but just before I did the Cell replacement I am pretty sure the fuel level and outside temperature always read correctly

 

I did learn a lesson: prior to any HV battery repairs, one should record videos or take photos or notes of what is working or not on the MFD and dash...which I didn’t do

 

Can someone

Can someone kindly tell me how
To balance the cells? The guy o bought the used cells from told me to run the AC with the “start” light on (which would be run mode) for about 30 minutes until it depletes the HV battery. Then drive it up a hill if possible to completely deplete what’s left of the HV battery.
Then drive normally to recharge the HV battery.

I’m asking myself why not just remove the fuel pump fuse and drive the car until the HV battery is depleted? It should take just a few miles. In fact my fuel is low and I could just let it run out of gas (bring a gas can with me to rescue myself) and drive it on battery to deplete the HV battery. That would skip using the AC to deplete it

 

To SFO:
Awhile back I had P0420 and CEL constantly. Last month I got the red triangle and car ran weak intermittently and strong other times and the HV battery fan ran constantly - so I replaced the two weak cells.

Yesterday I replaced the cat and downstream oxygen sensor and cleared the P0420 and P0430 codes.

Today I drove it an hour and no codes nor red triangle...until I drove to lunch and got the red triangle, CEL and the round brake circle with shoes icon. See picture. Had scanner with me and got P0301. I’m ready to check the sparkplugs and replace the #1 coil pack for $10 if you guys think I should. Car has 148k miles on original plugs and coil packs.

 

View attachment 182822

To SFO:
Awhile back I had P0420 and CEL constantly. Last month I got the red triangle and car ran weak intermittently and strong other times and the HV battery fan ran constantly - so I replaced the two weak cells.

Yesterday I replaced the cat and downstream oxygen sensor and cleared the P0420 and P0430 codes.

Today I drove it an hour and no codes nor red triangle...until I drove to lunch and got the red triangle, CEL and the round brake circle with shoes icon. See picture. Had scanner with me and got P0301. I’m ready to check the sparkplugs and replace the #1 coil pack for $10 if you guys think I should. Car has 148k miles on original plugs and coil packs.

 

So, I guess removing the fuel pump fuse or relay (if there is one) or unplugging the fuel pump and driving the car on the HV battery won’t uniformly deplete the cells. So the guy who sold me the used cells is probably wrong?

 

So, I guess removing the fuel pump fuse or relay (if there is one) or unplugging the fuel pump and driving the car on the HV battery won’t uniformly deplete the cells. So the guy who sold me the used cells is probably wrong?

 

Maybe I can use a lightbulb or motor and discharge each cell to some expert-determined voltage Before reconnecting them all and driving the car to let it charge the cells (which should be uniform). But catching the motor or lightbulb at the right voltage may be a pain. The time it takes can vary a lot

 

On the other hand, driving the car out of gas seems to kill the HV battery in 5 minutes so can I assume you can safely discharge each cell at a rate that only takes 5 minutes to deplete it? As long as I blow cool air over the cell to keep it cool?