I have a 2007 HIghlander Hybrid with 212,000 miles and I put in a new Hybrid battery to see if I can get better MPG but I was getting 15MPG on average. I got the battery off Alibaba. I put the battery in early December and been driving it since, but the thing is I took apart the original hybrid battery in October to determine what kind of battery I needed and put it back together. Suddenly, I'm averaging around 25MPG. I figure it can only get better once I install the new hybrid battery. I'm back to averaging 15MPG. It's probably worse now since the car likes to use the gas engine the moment I even push the pedal. The car doesn't produce a check engine and this is what I see from Dr Prius. The more I drive it the more often it runs off the electric motor, but it usually starts to happen after an hour of driving. I'm wondering if I'm suppose to reset something so it makes better use of the battery? Is it because the battery is too cold because it's Winter? Here's the old battery that I took this snapshot from August 2024.
Just cleaning the bus bars has saved some batteries that have gone bad. When you took it apart and put back together, you may have cleaned up some contact, which lead to better fuel economy.
There wasn't any. I just took out the three battery packs and placed new ones back in. Good news is that I did drive it for 5 hours, which was 2.5 hours each way and it slowly improved. At slow enough speeds it would stay in battery mode, which it wasn't doing before. I had Dr Prius running the whole time and it got better. Started to use the hybrid system much more often the more I drove it. I just don't know why it improved and if it'll stay like this when I drive it again tomorrow. The battery temp went up significantly the more I drove it. I'm going to see if new plugs might do the car some good. I did a bunch of work to the car but spark plugs wasn't one of them. First 2.5 hours. Second 2.5 hours. This is how the batteries looked when I installed them. Except mine are green.
I assume you mean battery modules. Where did you get new ones since they are unavailable to anyone except Toyota? If you changed out for reconditioned modules, you definitely retorques those bus bar connections. Checking and retorquing the others may have improved things further. The battery packs work best when properly balanced, though. Any reconditioned battery bought from a company has not been properly rebalanced due to the time and attention needed to do a proper job.
