Electrical safety when working on the hybrid battery

In the battery itself, when you pull the service plug, you don't have a ~ 202-volt stack anymore. The service plug splits it, not right in the middle, but into roughly a 130-volt and a 72-volt stack. You would still want to take care around those.

If you next removed a bus bar from the middle of the 130-volt stack, you would have two 65-volt stacks (and a 72-volt stack), and you could likewise strategically choose the next few bus bars you remove, to get quickly down to less-dangerous voltages. Insulated tools and gloves are common sense for such work; you should also be familiar with how to test electrical gloves for any pinholes.

At voltages below what might give you a dangerous shock, the battery modules might still have adequate current capacity to do other unfriendly things, like spit molten steel from your screwdriver tip into your face.

Do people often jump in with fewer precautions and live to tell the tale? Sure ... I've also done various things in my life that I got away with, but those still aren't what I would teach anybody to try.

One more thing to remember: isolation faults (the P0AA6 code) can be a frequent reason for working on the battery. Such a fault, by definition, means the current paths you know about aren't the only ones there are, and they don't all have to be interrupted by pulling the service plug. Working on a battery because of a P0AA6 code calls for all the precautions you can muster, until it's disassembled and cleaned up.

 

Watch videos of Green tech green bean guys changing n working on battery in Prius. Lots videos from the pros and owners of these businesses.make a mental note of safety equipment gloves etc . And nite wet businesses are located mini strip malls etc . Remember these aren't lithium-ion batteries they're lowly NIMH old cell phone tech . Not much blowing up etc going on . Swelling leaking yes .

 

Hi @indel, in the past 5 years selling hybrid batteries, I honestly haven’t had a single customer (no matter how naive they were) get seriously hurt or kill. That said, the risk is always there, so it’s worth respecting.

From personal experience, the most you can get is a pretty solid zap and you’ll definitely remember it… but you can usually shake it off assuming you don’t have any heart issues.

Hybrid packs are roughly 220V DC. DC generally doesn’t penetrate skin as easy as household 240V AC (60Hz) can, but it can still bite you hard.

Also, those super thick high-voltage gloves can make the job almost impossible. The main rule is simple: don’t complete the circuit. Example: you can touch the most positive terminal stud with one hand, but the other hand better be smart and don't touch the most negative terminal stud even with the service plug off.

Pretty sure I made a video on this years ago — I even got zapped on camera for the love of science. Painful, but manageable

 

Discussions of what it takes, AC or DC, to ruin a person's day occasionally happen here, and every now and then it is worth reposting some information that's often kept on display around physics labs. I'll put the link here again, 'cause it doesn't hurt to have it in multiple places.

Electrical Safety: The Fatal Current

I've put that link in other threads (like here, with other interesting links and discussion).

The web site I was linking to seems to have had a reorg around 2024 and the links I posted earlier don't work. The one above is to the Wayback Machine, so should continue to work.

 

Right shoe soles . And what not . I was carrying a rack of modules and had something touching . I could feel the juice biting on me said 175V . Set rack down it stopped . Duh. Put it on slow charge went to parts store .