Apparent Dead Battery - To Jump or Not to Jump

^^ I'd ask the dealer what they prefer. Did your car come with a couple years of free Roadside Assistance? (I bought mine too early to get that.)

Another choice, if it will jump start from another vehicle, may be to drive it in. Just don't turn off the ignition, because it will need yet another jump to restart. The ICE periodically turning itself off is not an issue, as long as the ignition is kept in Ready mode. But again, ask the dealer first.

 

It's too late now, but you should have called your free Toyota Roadside assistance, but then again I always take the easy way out.

 

Thanks, Fuzzy1. I think I'll return that Stanley product and just go with a 2A trickle charger (Stanley also offers one), or a 4A might be ideal.

The 8A feature is manual, but it uses 6A otherwise and adjusts downward as the battery charges. I'd feel safer with one that maxes out at 4A. Thanks to you and Bent for confirming the 4.2 amp limitation on the battery itself.

 

Fuzzy1, I see a lot of automatic chargers under $100 but little at the 4/2 amp level. Would this one from Sams Club do the trick? 4/2 Amp Battery Charger - Sam's Club

EDIT: Nevermind, just a 2-amp trickle charger for 12-volt batteries (it increases to 4-amp for 6-volt batteries).

 

Did you stick with low charging current as listed in the manual, and not let the voltage rise above normal operating voltage? My other car normally runs 13.8-14V. My Prius is running 14.7V these days, which seems high. Someone else indicated that it runs higher in cold weather, but I wasn't tracking this before winter.

The TSB to not use standard chargers may be related to why others have suggested letting the car's inverter do the bulk of the battery charging, in Ready mode, after the car is jump started. But you need to get it started first.

No clue on towing quality.

Neutral is not available unless the car is in Ready. When powered down, it can only be in Park except is special emergencies such as powering down at highway speed.

 

It looks like 4-amp charging is only available manually on chargers well over $100 and are more feature-packed than I require. I can't believe someone hasn't furnished a product specifically intended for charging the Prius battery.

 

This is still very very cheap compared to the cost of fixing do-it-yourself errors. Don't be afraid to exercise this option.

 

Ditto that. At this point $51 is a bargain. If it doesn't take a charge, pay the $200 to have them install a new Toyota battery.

 

10V is nowhere near the level where a switch or intelligence for battery type matters. This low, all of them are equally dead.

Does your charger have an ammeter display to show how much current was actually going in? I'm looking for the possibility that it reduced the current until the voltage rose to some predetermined level, in which case there is a possibility that you didn't have it on the charger long enough. If a built-in ammeter shows it was actually taking anything close to 2 and 4 amps, it seems very unlikely that this battery was salvageable in the first place.

 

Odds are the roadside assistance would be farmed out to a subcontractor so results could vary. However, if you're getting Toyota's Roadside assistance and they manage to do damage to the car int he process, then they'd be liable for the repair.

As such there's less financial risk calling for your free roadside assistance than jump starting the car yourself (and thereby accepting the risk that you might do it wrong).

 

Traditional flooded batteries are no longer considered safe inside the passenger compartment. The Prius 12V is effectively inside, so it needs something that doesn't leak acid, and doesn't put acid fumes or aerosols into people's breathing space.

Yup, that happens too. But see Kornkob's reply.

Yup, usually.

Your dealer is blowing smoke on this one. The Prius can have problems -- PriusChat has lots of threads about 12V batteries, vacations, and airport parking -- but 4 days is absurdly short unless the battery starts seriously undercharged or near death.