Can't jumpstart - help!

Replace the 12v battery. It's not taking a charge and is probably due for replacement (assuming that it is the original battery).

 

Hi Peaquod, welcome to PriusChat and sorry you are having problems.

This one sounds a bit unusual. As you report the old battery voltage, please check the new one as well to make sure that it is at least 12.6 v unloaded.

It might be helpful to disconnect the new battery for several minutes and then reconnect and try another start. If nothing changes, it is hard to see an alternative to a tow to a Toyota shop. Remember, no flat towing.

I don't want to instill unnecessary concern, but if by chance the jumping you did before involved a polarity reversal, you might be looking at some damage. The T shop should be able to sort it out, but by all means post more details because we can all learn from it.

Good luck!

 

Hopefully. Replace the fuse and find out. As long as your cables were hooked up correctly your inverter should be fine.

 

I have not done it, but can generally remember the instructions posted by others.

1. Disconnect 12 v battery
2. That fuse box needs to be unbolted and lifted up - not sure exactly about the tiedown points
3. With box lifted, the underside of the fuse needs to be unbolted. It is not a blade fuse
4. You bought a new fuse already yes?
5. reinstall

This is the scenario I feared, and I very much hope that the fuse is the only fatality. You'll know very soon.

For those with outboard inverters who may view this thread, pequod presents the symptoms you might see if your gadget presents a big load, and you have not fused it conservatively upstream. Take heed.

To all - never ever reverse polarity to Prius with an external battery or charger. Not even in your dreams.

 

Prius: Mods to replace OEM Battery

not sure what you are referring to, however, this may help.

 

Excellent work. Hopefully not to expensive a fix.

 

Sounds like the 12 vdc aux battery has a shorted cell. Usually, a battery with a shorted cell cannot be boosted, or if it can be, some odd things happen

Let's hope it's just the Big Mean Fuse. If it was the inverter assembly, you could be looking at +$4,000

 

That sounds scary. So it was an electrical short or defect in the fuse box assembly itself?

Boosting or charging the little 12 v battery is safe, as long as you follow reasonable precautions

I use a VDC Battery Minder on my Prius, actually have for almost four years now. It works fine and the battery is strong

 

I can't find the link here right now, but someone described their experience replacing the 100 amp fuse. It involves removing the underhood fuse block, and is complicated by stiff wires with no slack connected to hard-to-access terminals.

 

Where is that fuse box assy?

 

Hello to all - Happy holidays. After reading several posts like this one I purchased a new 12V aux battery at the 2 year mark. The old one is on a float charger in the garage and is used for emergency type stuff (ham radio - powering my tankless water heater in power outages etc.) My wife and I drive our 2005 prius alot every week, so our 12V aux battery is always charged up. The float charger keeps the spare battery at 12.42 Volts, occasionally I will charge it with a battery charger at 12V and 2 AMPS. Usually only for an hour or two max.

My only advice to new owners would be to make SURE that you do not leave any lights on in the car, doors open all night...etc etc.

This great little car seems to have an achilles heel that is the 12V aux battery. Heads up in the winter months with your prii out there. Lucky for us our car is parked inside our garage at night, and overnight temps in Southern California are not that low.

 

Remove the cover of the main relay/fuse box located near the inverter. Find the 5" long white/clear plastic box within. That contains the various fuse links.

 

OK Pat, I wasn't sure if the OP was talking forward or aft. I wonder what could cause a factory finished assy to short to ground, unless that area was tinkered with....

 

Hi Andy,

Recall that the OP's original problem was a failed 12V battery. Apparently the current surge while jumpstarting caused the fuse box to overheat (prior to the 100A DC/DC fuse link popping) and resulted in a short. 13.8VDC produced by the DC/DC converter x 100A = ~1,400W of power, which can produce considerable damage if focused on a small spot.