Apparent Dead Battery - To Jump or Not to Jump

You were wrong unfortunately. After the dome lights or the mirror lights are turned on manually, they stay that way until turned off with the toggle switch (or the mirror or visor is closed). x-(

The battery can be jumped fairly easily from the front (that's also explained in the manual).

I myself have a charger with varying amperage that I plan to use on the Prius battery should I ever have the need. It actively monitors and adjusts amperage so it shouldn't (theoretically) feed anymore current than the battery can safely handle.

 

If you really want to be safe, to avoid a mid-four-digit repair bill for incorrect jumping, the hatch can be opened from the inside. It involves folding down the rear seats, crawling into the rear compartment, pulling up the floor mat, and finding the mechanical release. My salescritter showed me, but I haven't done it myself. It should be described somewhere in the owners manual.

Some lights shut off automatically, some don't. And it is also surprisingly simple to defeat the headlight auto-off.

Yes.

 

It would certainly be safer to remove the battery to recharging. This removes the possibility of damaging other electronics. The Prius infamous for a horrendous repair bill from incorrect jump start attempts.

Most advice I've seen for charging in place is to put in only enough charge to boot the car into Ready, then let the car finish the job through the HV-to-12V inverter. This will actually take many hours. If you don't have lots of drive time immediately available, it can be left in Park and Ready for an extended period. The ICE will occasionally fire up to maintain HV battery charge, so the car would need to be in a place where the exhaust fumes will not cause a poisoning risk, and it won't get stolen.

The. manual says to limit charge current to 4.2 amps. Several folks here have said 2 amps, which matches my old small charger. I'm not worried about mine causing an overvoltage condition in the 2 amp setting as the battery fills, but cannot speak of anyone else's unit.

I hadn't noticed the note to disconnect ground cable, it is in a different section than the jumpstart advice. The note to disconnect the cable follows a note about the risk of hydrogen gas explosion, which is a risk when causing sparks at the back. I'm suspecting that a cable disconnect will prevent an inadvertent fast charge, and excess gas, should the car go Ready and start charging the battery at the same time the external charger is running.

It would seem that slow charging from the front should keep any sparks away from any collecting hydrogen in back, but the warning to not charge in a garage or unventilated space still applies.

 

It depends. If you don't touch the switch after shutting off the car, and you do exit through the driver door, then these should shut off automatically, default 30 seconds but configurable. But if you turn them on after shutting off the car, or exit through a passenger door, then this auto-off feature is defeated.

 

The Prius has no alternator. Yes, you can jump it and run until full...the point at which will be a guessing game as far as I know (5 hours?).

I'm also wondering about the amperage, since the Stanley charger I bought automatically fluctuates from 8A down to 2A when charging batteries.

 

I have detailed answers for only a few items right now:

Its two motor-generators do everything that the alternator and starter do in non-hybrids, plus a whole lot more.

My manual calls out a slightly lower current, probably because it is a different trim level with a smaller battery.

This battery is smaller than the 12V battery in any other car you have had, and has a different construction (AGM?). It is not a traditional flooded battery.

 

Fuzzy, do you think this would be hazardous to use with the Prius battery? Shop Stanley 6-Amp Automatic Battery Charger with 8-Amp "Quick Start Timer" at Lowes.com

I have so far heard of one person here who has had no trouble using something similar on their Prius' battery.

 

About 2 and a half years ago I left the car at the airport carpark with the cabin light on.
2 weeks later when I got back the battery was dead.
I connected to another car with jumper leads (connecting to the terminals in the in the engine bay, as per the manual), waited a few minutes, then started the car and it went to 'ready'. Disconnected the other car and drove home (about 30km).
Haven't had any problems since.
Unlike other cars, there doesn't have to be enough charge to 'turn' the engine, only enough to get the computer to 'ready', then the hybrid batteries and the rest of the electrical system takes over.
Leaving the light on, only flattened the 12v battery, the hybrid batteries seem unaffected.

 

Probably so.

 

[ame="http://en.wikipedia.org/wiki/Absorbent_glass_mat"]Absorbed Glass Mat[/ame].

I'm going by the manual and labeling, and don't have anything else to add on that.

I'd be concerned about gas production, so I'm not going that high. The output of my own 6/2 amp charger goes high enough in the 6 amp setting that it would need careful monitoring, so I'd pass an anything without a lower setting.

I assume not, as this is usually a wear/maintenance item, but don't see a specific exclusion in the booklet. Tires are called out as warranted separately by the trie manufacturer, and I thought 12V batteries were likely to be treated the same.

Now that is bad. If it doesn't rise substantially and soon, it would suggest some bad cells.

PC has had many threads about battery replacements. In the past non-Toyota replacements required an adapter kit, but a drop-in replacement recently became available:
New Optima 12v Yellow Top D51 battery with Pencil Posts
Optima Announces Prius Replacement 12v Yellow Top Battery with Pencil Posts

My own Prius 12V battery is showing signs of either weak charging (despite a high bus voltage during normal driving this winter), or failing sooner than the batteries in the household's other cars. But I'm not yet to the point of having to make a replacement decision.