Installation of Yellowtop 12v Aux Battery?

From whom did you order the battery? If you ordered from eLearnAid, you will have everything you need, parts and instructions. If not, then you won't. They are the only ones that sell the Yellow Top with parts needed for Prius installation.

As for your questions:

1) The eLearnAid instructions should provide everything you need.
2) No. It's more of a convenience issue but if you don't have a spare 12V battery around, it's not a big deal.

 

1) The main issue is going to be removing the nut that secures the positive battery terminal connector to the fuse block. You might have trouble if you don't have a vise that you can use to hold the fuse block while you use a socket wrench to loosen the nut. Also, it is much easier to disconnect the negative cable where it bolts to the body, remove the battery, then work on removing the negative cable from the battery.

2) No problem disconnecting the battery, in fact that gives the ECUs a chance to power down and then reboot upon power reconnection. Don't be surprised that you will see a pretty big spark when you reconnect the negative cable.

 

Hello Pat, What is that spark? It is strange. it's almost like a sparkler, but whiter. Is that a HV discharge from the brake booster box? TY Andy

 

this might help ya out.

Prius 12V swap

 

Or my page. though it doesn't come close to Hobbit's details:
Prius Optima Aux

 

Hi Andy,

Well, it would not be high voltage since we are talking about the 12V bus. I would say that the spark represents a momentary current surge when 12V power is restored and the capacitors in the brake power supply as well as the ECUs charge up.

Even Classic, which does not have a brake power supply like 2G, will produce a pretty big spark when the battery is hooked up, due to the ECUs.

Also, if your cabin light and hatch light switches are set so that the lights will be on when you restore 12V power, their power consumption will add to the spark as power is restored.

 

You will have to reset the drivers window "auto-up/down". It's in the manual, but it simply requires you to run the window about 1/2 way down then all the way up and hold for a few seconds after it fully closes.

Then the radio station memory.

The capacitors that will produce the spark include the brake boost ones, the ones in the ecu, and the ones in the inverter. There may be others. If it worries you, you can use a 10 ohm or so resistor in series at first to charge them then "short out" the resistor. I try to avoid the natural reaction of removing the connection when it sparks, then reapplying it, thus getting -two- sparks. The less of those the better! Search for the "Ten Commandments of Electronics".

 

I live in Tampa Florida area and I bet its as hot here as Quam and I'm going on the 4th year on the oem AGM. Its doing ok. So there designed to last at least 3+ years imho if properly taken care of. PTCO means never ever killing it requiring a jump start which is extremely easy to avoid by just pressing the FOB lock door button every single time you get out of the car especially in the garage.

But if you kill the Aux Batt just once it will sulfate quite quickly and never take a full charge again.
Which has probably happened to your previously owned car's AGM.

By comparison here's what my original stock batt reads in MFD Display Check mode first thing in the am. Car has 30K miles:

Access standby: 12.4
Access w/ load: 12.1
Ready : 14.5

 

If the doors lock, then you know that all doors and the hatch are fully closed, so the cabin lights should be off (unless you left on a light switch.) If the doors don't lock, then it is likely that something is ajar.

Given your voltage readings, it is a good idea to replace the 12V battery now.

 

FYI: The OEM Prius battery is a standard flooded Lead-Calcium battery just like all batteries found in other cars, except it is physically smaller. It *does* contain liquid sulfuric acid, and can leak if the case is compromised.

AGM batteries, such as the Optima, contain only enough acid to wet the separators, and will generally not leak any, even if the case is cracked open.

 

Well, the 12V batteries in my Prius have been AGM, and that is the spec in the Toyota technical and repair literature. I've opened the original equipment battery on my 2001 when I replaced it, and could see the fuzzy white mats between the lead plates. I also tipped the battery on its side and no free liquid came out.

I also removed the battery on my 2004 and shook it. No sound of liquid sloshing around within.

I recognize that some owners have found liquid acid in their batteries, which is very strange since the battery exterior markings are the same.

 

Yes, this is odd. All the ones I have looked at definitely have liquid in them. My 2008, and a friend's 2004 absolutely confirmed to have liquid. They are both GS "Nippon Denchi" units. I will have to check some of my other friends cars. You can actually see the water in it when you tilt the battery, though it's easier with a bright flashlight.

Also see Hobbit's excellent page here:
[SIZE=+1]Prius 12V battery exploration[/SIZE]

He clearly shows the same GS battery with liquid in it (he has a 2004 I believe). He postulates that the constant 14v sent in by the DC-DC may be boiling off more electrolyte than can effectively be re-combined. This may be doubly true in warmer climates as the DC-DC does not put out a temp compensated voltage. So maybe they are slowly turning into a "Starved electrolyte" battery! =)

 

That very nice, helpful Lady (Amanda?) at eLearnAid. She does not work here (at eLearnAid) anymore but she went on to get cast in 11 hit TV shows Including: Shameless, How I Met Your Mother, The Mentalist, Superstore, Fresh of the Boat and Pure Genius. Her stage name is Amanda Reed.

 

that's funny.