Rebuilt HV battery issues, please send help.

Welcome to Prius Chat .

Some questions:

• How many miles on your Prius?
• Are you charging and balancing when you rebuilt your pack?
• What code reader are you using?
• How long have you owned the Prius?

Good luck and keep us posted .

 

So, the car is able to go "ready" and will drive under battery power for about 50 feet before it codes out?

What are you using to read codes? There should be an HV Battery code in there somewhere

 

If you have a multi-tester, test wires and the light bulb from one the headlights, this will help you identify the bad module: Prolong® Battery Module Load Tester User Guide – Hybrid Automotive

Also reconditioning the remaining modules is fairly essential... You can do that with a bunch of RC / Drone type Nimh smart charger. Read more on the website above and once you're ready to do more work on it I can help you with more details.

 

Yep, I went thru exact same thing first time... All the voltages looked great, cleaned up huge amounts of corrosion, put it back in, put car back together and a few blocks down the road all the lights came on again. That's because all the batteries are wired up in series rather than parallel and once you get huge amps running through the system (120amp fuse is on an HV pack) the bad cell within the module screws it all up... Sometimes it's not the amperage, but just the resistance, which after a longer drive heats everything up, which makes the weakest cells weaker real fast.

On the bright side, it only takes an hour to do a two minute load test/discharge on each module and thanks to your forced charging before you pulled i tout you should be ok with state of charge when you put it back in... Also sometimes after rebuilding a pack, it'll be fine on short trips or longer ones in cool weather, but soon as you're on the highway for an hour and things heat up...

Currently have this concern with one of my friend's Prius I've been working on and I know there's a bad module in their somewhere and I still have more to learn about finding the bad one before it's really bad. In the meantime, my friend is happy her car is mostly fixed, just not yet warning light free on longer freeway drives. In time the module will be easier to identify...

In the meantime, I keep pondering all the data I got from: 1) load testing, 2) from three rounds of increasingly deeper and deeper discharge and recharge (aka: battery conditioning/restoring capacity/lowering resistance) and, 3) Hybrid Assistant App via Hybrid Reporter app via OB2 Bluetooth device (learn more here: Hybrid battery diagnostic and repair tool for Toyota and Lexus ) I've a fairly good sense of which modules are suspect, but not to the point I want to start wasting my friends money replacing more modules yet.

Similarly, you bad module will be more obvious as time goes by... Hybrid Assistant app allows you turn battery pack cooling fan speed up to full blast, so at least if you get warning lights, you can try to get home before things get too hot and ECU blocks use of Battery pack and then you're pretty much stuck till it cools down again. To me this is a worthwhile hassle to save money... To others on here they think it's silly and a waste of time. But compared to the cost of a new or rebuilt pack...

 

Yea... You need to use a smart charger calibrated to the nature of NiMH Battery module... A mechanic friend of mine loaned me a couple of SKYRC IMAX B6AC V2 chargers, which can charge all different types of battery chemistry. Hobbyists who fly drones and RC planes and cars use them and they sell for about $40 each on Ebay. Be careful to not buy knock-offs with different looking graphics on the front.

In gratitude for my friend loaning me his 2 chargers I bought a couple more, so now we have four of them, which speeds the process up big time. I also found a deal for (8) 12v 50w bulbs for $15 and some three way switches on ebay which I'm designing into a discharge and recharge rack that sits on top of the battery pack so there's no hassle with moving wires/alligator clips around and it speeds up the process.

I've got a digital kitchen timer too and and those free multi-tester you can get via coupons at Harbor Freight for each module as well... When you flip the switch up and hit the timer a module discharges at 100w / 2 bulbs... As the voltage gets really low and discharge speeds up you hit the switch down and then it discharges with just one bulb at 50w.

Perhaps you can find some others in your part of the country who need Prius battery pack reconditioning to help offset some of the costs? Or if you buy a wire harness / fan control for $150 from Eric Becky on here is in Wisconsin and will mail/rent you a Prolong Charger if you mail him a check/deposit.

 

Those are great numbers! Most of what I've worked on is in the range of .2 and sometimes as high as .3 so that's good news... Tomorrow I'll re-read the thread and see if I can offer more insight. Hopefully others will do the same. Next step is getting more data doing charge and discharge/reconditioning to extend the life of the pack. Once you're sure it's not corrosion, we'll have to go beyond the battery pack...

 

Hi Corban, I hope you already fixed the HEV battery issue.