Need Bigger 12V battery...

Ken,
Is it safe to draw close to the 120 amp max constantly from the converter, or is there a duty cycle? I'm thinking of using the Prius as emergency power. I'd like to tap the traction battery directly, but that's probably prohibitively expensive.

 

It is constant 120A max, however I don't know how safe it is constant 120A consumption.
I think it is a same kind of question "how safe is it to drive Prius 110mph for hours?".

Anyway, if I were you, I'll try to limit up to 100A consumption on Gen3.

Ken@Japan

 

If you haven't seen before in my other posts, I have a fairly significant install and am running a JL HD900/5 which is kind of the same as running 2 amps. Either choice between the Alpine and JL you should be fine. They are so efficient with their power they are quite amazing. I am not completely done with my install as I am going to add another headunit into the center console to take care of audio duties as there just doesn't seem to be a reasonable way to get good sound going through a processor coming of the JBL factory amp. I have over $5k tied up in my system so far and am so disappointed in how it sounds. The installer had used an Alpine headunit at one point and bypassed everything just to make sure it sounded the way it should and holy cow, it was just absolutely amazing. Truly the audiophile sound I was and still am looking for. Only problem now is baby is on the way in less than a month, having surgery on my foot in Dec. so extra money won't be coming my way until I get back to work next spring and I just have to deal with it until then. Then from there the factory unit will play the voices through the stock dash speakers that come from the navi and phone stuff. Darn shame it has to come to that but too far over my head in this install to stop. Good luck with your install.

 

For those not good with numbers, 13.8V at 120A is indeed 1660 watts - not 1656. That also 2.22hp

 

Your calculator must be made in China.

Ken@Japan

 

In what number system? This must be new math.

Tom

 

No - it was made in Redmond, WA

When calculating numbers, you cannot add accuracy to a number (unless you are looking for an inaccurate number).

13.8 has (3) significant figures. 120 also has (3). The resulting number should also only have 3. So the accurate answer is 1660 - not 1656.

Same for HP if the combination of numbers have (3), then the answer should have (3)....

 

Ah, so you are talking precision, not arithmetic. That's a relief. I though you might have a spider caught under the index of your slide rule.

You can add as many significant figures as you wish, although they might not be useful. As you have pointed out, in engineering and the sciences we tend to explicitly list significant figures, even if they are zeros. In finance and accounting the rounding rules are completely different. For some reason the accounting people don't want you to create money. Go figure.

In the case of a 12V power bus it is even worse, since you are talking about nominal voltages. If we want to get picky, we should probably refer to a range of voltages, just as we do with AC power: 110-120VAC. The 13.8 figure is common for conventional voltage regulators. I believe it might be a tad high for the Prius. It seems that the Prius likes to run at about 13.7 volts, but I haven't seen a formal specification.

On to other nit picking: Sticklers Unite!

Tom

 

a64pilot, go to Youtube.com and search "prius emergency generator" to see what people have done with their Prius's to power their homes.