HV SOC 25% after driving with ICE disabled due to u0100, how to recharge and proceed?

Hello and thank you glorious community, I've learned alot lurking, first time posting for assistance.

BACKSTORY...
Bought an 05 last year for 4k cash, had 128k miles at the time. Original cat was stolen, seller installed aftermarket part.

To get rid of o2 sensor engine light, I bought a bypass elbow adapter and called it a day. The adapter made the cable dangle under the car more than usual, but nothing crazy.

THE INCIDENT...
I go to pull over on the side of the road at night, going slow of course, maybe 10-15 mph. KLUNK! Passenger side tire drops hard off the curb (I couldn't see how steep it was) and I bottom out, hearing and feeling the car scrape against the road.

I'm stuck, I try to reverse, no go. I rev up hard in drive and am able to get out after the tire finally got traction on the sandy grass. I feel another smaller KLunK as I get out of there and then I hear a loud BEEP!

Red triangle, abs light on, tire pressure light on, car with squiggly lines light on, warning car symbol on top left corner of HUD, fuel guage full and flashing, outside temp E on HUD...ICE is not running. I drive not even a mile to pull over in a parking lot on just the battery. Shut off car, pull codes with obd2 and Torque app:

U0100, lost communications.

To the internet I went and learned all sorts of things from how common wire connector corrosion is to how common it is for HV batteries to become victims to hard to diagnose, unrelated issues.

WORK DONE SO FAR...
1. Taped up frayed wiring on o2 sensor. The klunk damaged the wiring a little, exposing bare metal on the wires.
* I attempted to start the car after doing this and clearing codes. Triangle and all lights came right back on, ICE did not start, NO ready mode.
2. Changed the 12v. It was six years old.
*had a spark shower when a posi cable intended to go to an inverter made contact with the frame. Car was OFF ...I'm okay right? I also attempted to start the car after this. Key word attempt. No dice.
3. Cleaned HV battery fan. Buggah was loooong overdue.
*I did NOT attempt to start after this. After changing the 12v and running Dr. Prius I noticed the HV SOC was at 25%!! Not good!
*I also did NOT check for corrosion at the fan connector. I learned about that issue after putting it back together of course hehe.

CLARITY NEEDED...
So I'm saying F it and getting a whole new o2 sensor tomorrow and will install that, and while I'm at the store I'll drop off the new (but spark showered) 12v battery to charge because might as well. Lastly I'll pick some fuses just in case...

I read a shorted o2 sensor can blow the ec1 fuse, telling the engine not to start. I haven't checked that but will first thing tomorrow.

So,
1. Check ec1 fuse, replace if needed, check other fuses as well.
2. Install new o2 sensor because frayed wires are asking for trouble
3. Check/Charge spark showered new 12v battery, reinstall, check for corrosion at fan connector
4. Determine if it is safe to start car with such low HV SOC
5. If yes, clear codes and attempt to start. If no,
6. Charge HV battery externally, clear codes, attempt to start
7. Get new HV battery. Let's hope it doesn't have to come to this...

Thanks again for sharing some time and wisdom.

TLDR; Whats the lowest HV SOC it is safe to start the car with?

 

Thanks! Good to hear the 20% guidance.

Mini vci cable is on the way. No mobile mechanics in my area with techstream access. Not gonna pay to tow to pay someone else to diagnose..

Until I use techstream I won't clear anything using my obd2. Will be checking fuse today and o2 sensor replacement.

Can I pull obd2 codes after the above mentioned replacements in ACC/IG ON mode to determine if I fixed the problem? Don't want to try to start and drain HV more.

I'll keep this post updated as things move along

 

Disconnected neg from 12v battery, replaced o2 sensor with new. Reconnected battery.

Ran Dr. Prius in IG ON mode and got the attached screenshots.

u0100, p3000u0100 from 'READ BATTERY ERRORS'

No codes found from 'READ ENGINE ERRORS'

I finally found a mobile mechanic with techstream that's coming out tomorrow. Any advice on how to get the most out our meeting? Anything to ask him to check besides just running codes?

EF1 fuse is okay, as are others in the box. What else can I inspect? Ecu connections are next on my agenda...

 

Car Is running again

Like a lot of people here I posted and asked questions regarding problems that have been solved in other threads. I searched a fair amount before posting, but found the solutions to my issues only afterwards.

My smart dumb self couldn't identify that the EF1 fuse (not EC1 mentioned above, typo), was INDEED actually BLOWN due to the o2 sensor shorting. I replaced the fuse after installing a new o2 sensor and after clearing codes, all is well.

The mobile mechanic was competent. He listened as I ran through my steps of logic and made sure everything I did was done right. By double checking my work we found the blown fuse. I checked it myself beforehand but expected it to be melted and brown or something more than just the connection inside not being connected. Duh. He acknowledged my efforts and gracefully summed it up to an unexperienced eye needing guidance.

Props to the OG's of this forum that pave the way for new kids on the block to learn and grow. Happy to be back driving around again and a couple notches smarter!