Can you jump the HV battery?

Sorry but that really wasn't a good idea the FIRST time.
But I get tired of telling people the truth about "fixing" a worn out battery.

NO, the weak cells will cause the entire pack to not charge properly.
That is what the car is trying to tell you......and it wouldn't work any better if you tried to use an external source.
AND it would be dangerous to boot.

Forget about it, please.

 

First thing I would do is scan the hv battery voltages and state of charge. Plus verify the 125a fusible link inside the engine fuse box is good.

The first can be done with a $35 Bluetooth adapter and Car Scanner or the Dr Prius app. The second can be visually inspected or checked with a meter.

 

Ignore Sam Spade... Yes you can charge and balance your HV battery with a high voltage DC trickle charger. Your wall outlet won't work because it's AC not DC.

Maxx Volts & Hybrid Automotive sell an overpriced product that trickle charges, or you can build one yourself for $100 here: Build Hybrid Battery Maintenance Gear For Under $100 | PriusChat

When Nickel-based batteries get old they develop poorly conducting crystals in the cells and lose capacity, but by charging and balancing with a trickle charger and then using light bulbs to discharge to lower and lower voltages several times after each charge and balance you can bust those crystals up and get back to 96% capacity. Do this every 18 months and your old battery pack will last a really long time.

Of course if you got error codes we need to get those fixed first... And if you have a bad cell, you'll have to replace that module, which sell for $35 each.

 

Death rattle?

 

That's just an engine running on fewer cylinders than it was meant to.

 

What's the miles?

 

The headline topic is can the hv battery be jumped?

 

at 340k miles why not get a less-used engine? ...or use a younger one as the rebuild target?

 

If we knew where you were... ?

You have a very bad "head gasket" with likely a warped head and scored cylinders. Probably have a bent rod by now, eg a blown engine. It would be a lot of work just changing the gasket to find its still broken when you get done or three weeks later.

I would go with a professionally rebuilt engine shipped to you if you don't already live near a city with availability. You get new rings and maybe pistons along with a pro cleaned and rebuilt head. Otherwise a used JDM engine. Last resort, a used junkyard engine.

 

How did you try to charge them? How thin were the cables and at what amperage
did you try to charge them with?
Your BEST bet would be to get the Prolong system. After cleaning up all the connectors,
install the harness for the Prolong system then run it through the cycles. Charge, discharge,
charge, discharge, charge, discharge, then the final charge.
That will safely balance the whole pack and regenerate it.

 

Bad, BAD idea.

If one or more of those cells is very weak or effectively shorted,
when they are all connected in parallel, all of the good cells will try to charge the shorted one.......
AND an explosion or fire can occur.

AND if doing a single cell was overheating your cables, trying to do them ALL at once will ........
Well what do you think it might do ???
HINT: Melt the cables.

This is seriously dangerous stuff.
And this thread is a perfect example of why anyone with no real electronic knowledge should NOT be
screwing around with the hybrid battery.

 

Or a less used car. Fixing this one is like putting a band-aid on a gaping wound.

 

How DARE you try to deter someone from their chosen path.
Negative comments are a sin.
Even if they are absolutely true.

 

Chalk up another one for noticing what the codes are telling you.

There are a few codes that actually mean "hey, the supply voltage isn't great." If you've got codes that really are caused by your battery, the chances are excellent some of them will be those.