Check Auxillary Battery

<div class='quotetop'>QUOTE(cubbyg @ Mar 4 2007, 08:57 AM) [snapback]399907[/snapback]</div>

The 12 volt battery doesn't need to be large. It only needs to boot up the computers and a few minor power draws during start up. Once the computers are running the bigger NIcads are in "charge". Biggest touble comes from leaving a light on somewhere and draining the 12 volt. See my signature for an idea for you.

 

<div class='quotetop'>QUOTE(Gadgetdad @ Mar 4 2007, 01:05 PM) [snapback]399909[/snapback]</div>

I did this. One day I went to my Prius and it didn't recognize me -- the auxiliary battery had been completely discharged. Apparently I left my light switch on without driving it for 4 days. The dealer checked out the auxiliary battery, and they couldn't find anything wrong with it.

Because the light goes off with the light switch left on, I figured that it would not do any harm to the battery. The manual does say not to leave the light switch on for an extended period of time. I didn't think 4 days would be considered to be an extended period.

 

I know my solar panel gizmo I bot at Pep Boys works because there is a tiny Blue light that comes on when it is outside. Whether it actually charges anything I haven't tried to verify! I leave the 4x10x5/8 unit on the vast dashboard (underneath an un-tinted windsheld).

 

I was having trouble with my 12 vdc battery my first winter. Short trips, -40, electric defrost always on, all took their toll. I'm becoming convinced that a handful of Prius cars are running around with chronically undercharged 12 vdc batteries.

I picked up at auction an older vesion of VDC Electronics Battery Minder, getting 3 of them for what 1 usually costs. Like any good battery tender, it will keep a "float" charge on the battery, and once a float charge is reached, will send an approx 3.3 MHz pulse to desulfate the battery.

I've been using mine for almost 15 months now, and even gone for a month, no issues whatsoever.

http://priuschat.com/index.php?showtopic=27100

http://priuschat.com/index.php?showtopic=27552

http://priuschat.com/index.php?showtopic=27897

 

<div class='quotetop'>QUOTE(Gadgetdad @ Mar 4 2007, 04:44 PM) [snapback]399978[/snapback]</div>

All the light shows is that the solar panel is seeing enough light to produce some voltage, it does not indicate that charging is taking place. In fact, I'd prefer a panel *without* an LED, because the LED robs you of 20 mA of current.. Sounds insignificant, but think about- for a small solar panel, the output of the panel may only be 100 mA, so that 20 mA represents 20% of the energy lost just to power a silly light..

My rough calculations (search the old threads if you want details; I'm not going to type them out again) show that you need a minimum of a 5 Watt solar panel to get any meaningful charge. Anything smaller might slightly offset the parasitic drain of the vehicle electronics, but will not be able to add charge to the battery.. In other words, they'll slow down, but not prevent the draining of the battery..

 

I thought those solar panels wouldn't work on this car since the auxilary plugs aren't active when the car is shut down? is this not true?

 

<div class='quotetop'>QUOTE(TomorrowMatters @ Mar 5 2007, 12:32 PM) [snapback]400512[/snapback]</div>

Tis true unless you have wired to be constantly "on". Coastaletech has a kit for cheap.

I will check with the mult-meter to see what kind of mA I am getting net of the LED! There are larger PV panels that can be purchased that will do the job.

Lee

 

Instructions on how to check status of battery;

http://www.elearnaid.com/12vobaforpr2.html

Prius battery test procedure for all Prius Cars
Blue pertains only to the 2004 + Prius
Green pertains only to the 2000 to 2003 Prius.

Here is a battery test you can perform on a Prius battery that is easy to do. It will not always detect a weak battery that does not allow you to park you car for long before it is drained down by the security system.

However, this test requires no tools, is easy to do and will give you some idea of the state of your battery. You can also perform this test after the car has been parked for a while to see how well the battery holds up under the drain from the security system.



Do this test after you have driven the car for at least 30 minutes. This will give the battery a chance to be fully charged.
Put the transmission in Park.
Turn ignition switch to off.
Engage the parking break
(2000 to 2003)Turn ignition switch to Accesory. (do not start the engine)
2004+ Push in the power button.
Push Display button. (2000 to 2003)Top rocker to the right of the radio 2004+ top button to left of screen - "DISPLAY" will now appear in the upper left corner of your screen.)


Push on the upper left(1) and lower left display(2) of the display just inside the box. (see picture) Do this three times. Keep trying till the screen changes. If the word "Display" in the upper left hand corner of the screen goes away hit the display switch again.

Push on Menu in upper right of display screen.
Push on Display Check
Push on Vehicle Signal Check
You will see the 12 volt voltage displayed.
2004 + In accessory mode the voltage should be 12.6
With no electrical accessories on including lights the voltage should be fluctuate between 12.2 and 11.9. The lower the voltage, the less of a charge your battery currently has. If the voltage is low do not proceed as the load test might totally discharge your battery. (If you see a voltage around 13.5 you are seeing voltage from the high voltage battery being converted to around 13.5 in an attempt to recharge your battery. This normally does not occur till after you start the engine but might occur earlier if the battery is very drained.)
You can also test the battery by turning on the headlights, rear window heater and the heater fan. For a new battery the voltage would be around 11.3. If the voltage drops below 10.2 it should definitely be replaced. For voltages in between the lower the voltage, the lower current charge of your battery.
Note: If in doubt disconnect the 12 volt battery completely (start with the negative post to avoid shorting the battery) and hook it up to a battery tester.

 

<div class='quotetop'>QUOTE(Sean & Ian @ Mar 4 2007, 11:05 AM) [snapback]399921[/snapback]</div>

I decided that anything over 3 days is an extended period of time and I turn both the headlights and the SKS off. I also store both SKS remotes at least 15 feet away from the car and 3-5 feet away from any electronics or electrical appliances (one of my SKS remotes is wrapped in foil...something I picked up here at PC).

 

<div class='quotetop'>QUOTE(gilahiker @ Mar 5 2007, 11:08 PM) [snapback]400683[/snapback]</div>

According to other more knowledgeable members, they stated that the car will stop "pinging" the fob after a short period of time if the fob is in range, say within 5 ft of the car?

If the key fob is out of range, I don't think you have to wrap it in foil, since it will reply only when ask by the car's transmitter.

Turning off headlights and SKS do conserve 12V battery power.

 

<div class='quotetop'>QUOTE(Gadgetdad @ Mar 5 2007, 06:15 PM) [snapback]400564[/snapback]</div>

Or, if you wire directly to the battery.. I've got a 15W crystalline solar panel directly connected to the battery through a small charge controller..

If you're looking for solar panels, try and get a crystalline silicon panel (array of individual cells that are dark bluish/purplish black with a distinct crystalline growth pattern visible on each cell) vs. the cheaper amorphous thin-film panels (brown to burgundy color, no pattern).. The difference is that while the amorphous panels are much lower in cost, but are 3x bigger and also have much lower efficiency and more importantly, they also lose up to 60% of their capacity in the first 6 months of life. Compare this to the old crystalline technology- yes, it uses much more silicon, it costs twice as much, but they are physically much smaller and maintain their capacity over time.. Amorphous panels tend to be more sensitive to infrared and can make up some of the difference in efficiency here, but this doesn't count for much behind the Prius auto glass which is IR absorbing..

So, for example, the 15 W crystalline panel I've got- it's physically about 14" x 12" and fits comfortably in between the speakers on the back deck of my Classic Prius. It is guaranteed to maintain 90% capacity after 10 years. Compare to an amorphous panel- a 15W panel in this technology is typically about 3 feet wide by 1 foot deep (ie roughly 3x the area), and after a year of service may degreade such that it only provides 7 Watts of output.. In fact, before I got the crystalline panel, I actually had a 5W amorphous panel that was about 15" x 15", so the crystalline panel I replaced it with had 3x greater output, and was actually *smaller* in size..

I didn't buy my panel here, but the following supplier has a number of solar battery chargers: http://www.batterymart.com/c-flat-solar-panels.html

The first two products are amorphous panels, compare their size with the other panels, which are crystalline panels.. That 20W panel is only a little bigger than my current panel and would guarantee that your battery gets fully charged vs. just slowing down the discharge..

 

<div class='quotetop'>QUOTE(luckyboy @ Mar 5 2007, 06:27 PM) [snapback]400569[/snapback]</div>

It's much quicker if I just take my Fluke DMM to the hatch, lift out the tray, pop out the trim piece, and put the leads directly on the battery post

Oh, here is a hint:

Make sure the cables are tight on the posts. The tiny ground wire is attached to the unit body at the rear of the car. Twice a year I like to back off the bolt holding the ring terminal to the unitbody, then tighten it up again, to ensure a good ground.

 

<div class='quotetop'>QUOTE(gilahiker @ Mar 5 2007, 08:08 PM) [snapback]400683[/snapback]</div>

What is it about people from New Mexico wrapping things in foil??? Does this inhibit aliens from attacking your Prius?

 

<div class='quotetop'>QUOTE(luckyboy @ Mar 5 2007, 06:27 PM) [snapback]400569[/snapback]</div>

This looked like a cool thing to check so I went out to my 2006 to try it. The (1) and (2) on the display just are not there...and I could find no other way 'in' to the display for other functions. Is this something that went away in 2006 or am I just missing something here?

Jim


<div class='quotetop'>QUOTE(c4 @ Mar 6 2007, 12:16 PM) [snapback]400893[/snapback]</div>

Most of your comments about amorphous solar are true and accurate. But a reputable solar cell manufacturer will warrent the degraded output of the cell. In other words, your 15 w amorphous panel will probably be putting out more like 20 w at first and degrade to 15 or so. I have been using amorphous for most most our home and farm electricity for almost 20 years. The first ones were pretty bad, and warrentied out for the next generation of improved cells. They have improved a couple times more over the years. They degrade less, and are still at rated power after many years (the most recent additions were WAY over power at first and are now at the advertised power).

Still bigger, though.

BUT, they are flexible. Some small ones fold or roll up.

Jim