HV Battery Question

For the battery experts, I am noticing the following things occurring.

1. HV Pack voltage drops below 180v under hard acceleration. It quickly recovers to over 200v during normal driving

2. HV Pack voltage goes to 265v under regen, quickly dropping to 200v on normal driving.

Internal resistance shows to be 21-24 milliohms.

Am I in the early stages of a battery failing?

 

These are readings on either the Dr Prius app, or thru my OBD scanner.

 

And the voltage readings, the extreme high and low show in red on the Dr Prius app.

 

I got out for an extended drive this evening. About 30 minutes. Other then the wild voltage fluctuation, the car is driving fine.

Should I start battery shopping, or is this just a product of the outside temps hanging out in the 20’s or below?

 

Deleted, double post

 

In other words, unless codes come up, I’m not really going to know that it’s time to replace it?

 

I have got a “too good to pass up” deal on a pack from a wrecked, low mile 2014 Prius. Someone knocked the bumper cover off it, but it popped all the bags, so it got totaled. The yard is pulling it today, and I’ll get it late tonight or lunch time tomorrow. I have a hobby 4 bank charger that I will use to make sure the battery is up to snuff before I install it.

 

Picked up the pack this morning. Showing 221v at the leads when removed from car. They took the cooling fan and everything else off of it. I’m off this weekend, so I think I’m just going to go for it. I personally know who took the battery out, and he yard drove it to the dismantle shop.

 

Swapped the newer pack in this evening. Took about 90 minutes. My heart sank as I hit the power button and was graced with a Check Hybrid System message. P0B47. I was set to swap the pack back over and it dawned on me, recheck all my plugs that I messed with. The voltage sense connector to the battery ECU wasn’t secure. It clicked a second time and all is well. I’ve been too busy hotdogging to see if the mileage is going to come up.

The charge percent is a lot less “fluid” then it was, so we will see.

 

Home to gas station to work this morning. Almost 2 miles from indicated 60% charge until ICE kicked in.

 

Top One Bluetooth OBD and Car Scanner/Dr Prius apps. Internal Resistance on newer pack is 17 milliohms. State of charge drops by decimals of a percent instead of whole digits of a percent during driving.

 

Five days and five commutes later. Economy has settled into 48ish MPG with warmup penalty for lows in the mid 30’s here. That’s a huge gain from the indicated 33 mpg that I was getting.

And the EV is 1.5-1.6 miles. I mapped it out today on one of my trips. If I could survive without needing the heat on, I could probably get another few tenths of a mile, as that’s about how long it takes for the ICE to kick back on due to coolant temp falling. This spring/summer I’m going to try and gain entry to the 700 mile club. I made it to the 600 mile club in 2018.