Proactively replacing 12v

My guess is cargo net? And of course the charge cable goes in the center.


iPhone ?

 

I just replaced my 2010 battery two weeks ago. It was down to 11.9v (103,000 miles garaged) and was giving all kinds of strange symptoms other than the battery. 7 years is starting to reach on longevity.

 

I realize you guys are comparing apples to apples but capacity is a factor also (which the factory battery is somewhat lacking). I had a Gen 2 with an Optima battery that had extra capacity, and it was around 11.8-11.9v, but it started everything up just fine. If it had been factory then it would have been kaput. It was only dead like that from having the door open, not from age.

To look at it another way, take these lithium ion jump start packs we are seeing everywhere now. They only output about 12.0v! If your car measured 12.0v it would be considered dead! But the secret here is that your car doesn't need 12.6v from the jump pack to start. It works good enough with the 12.0v because the pack provides extra capacity to keep the voltage from dropping any lower than normal, during cranking. (Talking about a conventional car of course)

And if I haven't beat a dead horse enough, a big battery at 11.9v may have enough power to start a small car yet the small battery that comes in the small car would not, at the same voltage.


iPhone ?

 

how many amps does the prius require at 12v to make it ready?

 

In my case, 11.9v was not powering up all the ecu's, just some. The engine would start but 1/2 of the instrument cluster was black, the Hybrid 1/2.

 

I don't know the exact answer, but I have heard of people powering it up with a cordless power tool battery. So I would guess only a couple of amps.


iPhone ?

 

thanks, would be interesting to test a battery that won't make ready, but shows decent voltage.

 

According to hobbit it could be up to 30 amps for a short interval.

-Chap

 

will a power tool battery do that?

 

Most of my power tool batteries are rated 2.0-9.0Ah. This rating is pretty simple to understand as a 9.0Ah battery will be effectively dead and in need of recharging when it puts out 9 A for one hour. I don't see that 30 A would be a problem for a battery like this


iPhone ?

 

thanks!

 

You're quite welcome. I don't have any 12 or 14.4 V tools' batteries or else I could try it myself.


iPhone ?

 

It takes something under a second for the Prius to pull in the main relay and the DC/DC converter to take over from the aux battery, so even if it drew a solid 30 amps for the whole second, that would be 30 ÷ 3600 = 0.0083 amp hours. You could still drive a lot of screws with the tool battery after using it to start the Prius.

-Chap

 

it's too bad that it isn't as easy to measure amp capacity as voltage. but it seems very few prius batteries have the problem of 12+ volts, but won't make ready.

 

A battery testing machine at a garage is pretty much the only thing. Unless you buy your own. Not worth it just for your own car(s).


iPhone ?

 

agreed. i wonder what makes some batteries lose voltage, and some amperage?

 

Losing voltage is losing state of charge, which happens during use, and then you charge it up again. Losing amperage is losing capacity, which happens slowly over time and many charge-discharge cycles. Once enough capacity is lost, the battery can no longer keep its voltage up, even when not under load.


iPhone ?

 

this is why i don't understand electricity.