Toyota Prius Forum banner
1 - 10 of 10 Posts

·
Registered
Joined
·
19 Posts
That is pretty cool! I wonder if any members actually have had experience with this product.
 

·
Registered
Joined
·
202 Posts
I wonder if it's really that great.

Quoting from thier site, "Solatec's photovoltaic kit (patents applied for) adds two flexible, conformal panels that charge the hybrid automobile's auxiliary battery."

So it just charges the auxiliary battery, not the main batteries? I don't see how that could improve the milage by 10%, as they claim. And in my opinion a 10% improvement is still within the range of possibility without any improvements.

I just keep wishing that Toyota would come up with something to allow people the choice to charge the main battery pack with either solar or electric. It seems it shouldn't be that hard to do.
 

·
Registered
Joined
·
669 Posts
sub3marathonman said:
So it just charges the auxiliary battery, not the main batteries? I don't see how that could improve the milage by 10%, as they claim.
I'm not arguing for it particularly, but the energy to charge the aux battery has to come from SOMEWHERE so I can imagine some small improvement in mileage assuming whatever HSD uses for an alternator (what DOES the prius use?) is gas or electic motor driven.

I suppose it might solve the "garaging" problem, at least if you park outside.

I agree, a combination of the EV switch and plug-in might be rather useful as you could "drain" the battery with foreknowledge of imminent recharging.
 

·
Registered
Joined
·
202 Posts
Following up on Astrowoman's correct statements, I was wondering what the auxillary battery actually did power. (I tried to search here but couldn't find anything. Please don't be upset if it has been discussed before.) If this battery does power some energy using equipment there could be some improvement. And as she said, you wouldn't have to worry about the dead battery if you left it for long periods of time outside, like at an airport.

Also, I guess I'm being a "naysayer of negativity," but their site says it costs $2200. With gas even at $4.00/gal, that works out to 550 gallons of gas you would have to save to break even. If their claim is true and it gives 10% improvement in milage, that would mean you would have to burn around 5500 gallons in an unimproved Prius, or at 50 mpg, go about 275,000 miles. And, if you delve further into the fine print, concerning the mpg improvement, they state, " Benefit is immediately seen on the Prius on-board fuel mileage display." That doesn't sound like a guaranteed 10% improvement to me.

Another interesting statement on their site, " Rooftop-mounted flexible (conformal) photovoltaic (PV) panels supply recharging power directly to the vehicle batteries." (bold added) But in reality it is only the one auxillary battery.

I wish something like this would work out, but this method doesn't seem that great to me, on a current cost/benefit analysis. Maybe somehow it could be improved.
 

·
Premium Member
Joined
·
2,815 Posts
Astrowoman said:
I'm not arguing for it particularly, but the energy to charge the aux battery has to come from SOMEWHERE so I can imagine some small improvement in mileage assuming whatever HSD uses for an alternator (what DOES the prius use?) is gas or electic motor driven.
12v battery is used to provide power to the computers, and the brake pump, at startup. Once the computers are powered up, they flip a relay that connects up the hybrid traction battery. It is the hybrid traction battery that powers one of the electric motors to start the gasoline engine.

If the car is off, or in ACC, the 12v battery is used to power the fan for the climate control, the interior lights, the exterior lights, the alarm system, SE&SS, the radio, and the other usual 12v accessories.

If the car is in READY (not sure about IG-ON), the hybrid traction battery directly charges the 12v battery (and also powers the usual 12v accessories) through a step-down circuit. (If you use the poor-man's DRLs (auto-off headlight feature), you probably notice that your headlights will dim when you turn off the car - that's the switch from the hybrid battery charging the 12v battery that is powering the headlights, to the 12v battery powering the headlights alone.)

There is no alternator in the Prius. There is also no starter (in the conventional sense). (The Honda hybrids do have a conventional 12v starter, but it is only used if the hybrid traction battery is too depleted to start the car on its own.)
 

·
Registered
Joined
·
669 Posts
mrv said:
There is no alternator in the Prius. There is also no starter (in the conventional sense). (The Honda hybrids do have a conventional 12v starter, but it is only used if the hybrid traction battery is too depleted to start the car on its own.)
How is the 12v battery normally charged?
 

·
Registered
Joined
·
7,161 Posts
The inverter includes a DC-DC converter, converting 207 volts down to 12V, much like your computer power supply at home. It maintains a constant 13.8 or 14V, depending if it is actively charging or not. When in READY (not Ig-On, the HV system is disabled then), the DC-DC converter provides most if not all of the car's 12V electrical power. It is fused at 100A, but probably puts out 80A nominal.

The traction battery is charged by ICE through MG1 as needed.

I really doubt the solar charger would help much, especially if the car is not left off very much. However, the solar cell panel could keep the 12V battery topped off so that the DC-DC converter doesn't have to charge it at all when you get going. I really doubt a 10% return.
 
1 - 10 of 10 Posts
Top