Solar panels (or solar cells) to charge hybrid battery pack?
 

Is it possible to charge the hybrid battery pack when car is not inuse by adding solar panels or cells to 2009 TCH?
Saw a 12v for a car battery one... if my car 12v system is over charged will it dump any to the hybrid battery pack? Can I config to charge multiple cells in the battery pack?

Might ask these questions at the Toyotanation website in the Camry Hybrid or Prius sections. Of at a site dedicated to hybrid/battery powered cars.

Doubt if you can get enough energy from a solar panel to charge the main battery pack as too large. The panels you see may be for the battery that starts the engine which is much smaller in capacity.

Plug in hybrids take hours to recharge from a dedicated electrical outlet, solar panels cannot output this quantity of energy.

Not up to speed on the hybrid wiring but would assume the starter battery and main battery are on different charging systems. I think the main battery has a higher voltage.

The main battery most likely is one unit, all the cells linked, charging would be an all or nothing affair for the battery cells.

Also
 

Posted to Toyota fans too.
Read that if the hybrid pack gets too low it will draw energy from the main battery to not drop below a certain level if not driven for weeks.

True, main pack is 288~ volts, but made of smaller cells. So if I just connected a solar cell to the pos and neg of one of the cells... that cell, in theory should trickle to it's neighbors?

204 modules in pack.

From a little research solar panels have been used at recharge stations. The charger output is high requiring a lot of panels to get the current.

As to charging a hybrid battery. If this battery has 204 cells they are in series much like ganging two 12V batteries to get 24 volts (a common setup for 24V systems).

If one 12V battery is connected to the charger the other would still be isolated. If charging the batteries individually (parallel)the charger would need to connect to each + and - terminal of each battery.

If the battery is charged as a unit (all cells in series) there are only two connections.

If charged individually then each cell needs charging by itself.

One issue with batteries in series is for best performance all cells should have the same charge.

Not up on hybrids and not sure about the hybrid pack drawing power from the main battery. There is an engine starting battery and main battery the runs the drive motors. On early Prius the starting battery would tend to go dead if setting.

Are you stating the main (hybrid) battery keeps the starting battery charged or the other way around?

After reading...
 

7.2v * 34 for the 244.8, my car booklet was different specifications than online. Who trusts online?

I had read that if the 244.8v nimh battery pack gets too low it will get energy from the 12v lead acid. Not sure if it is true yet, just read that, online. If so it has a built in converter of sorts. Think if the 12v lead acid is brimming with juice it could send some over to the nimh if that were the case? Guess it depends how they wired the car and what they told it's computer.

So maybe if I have a small solar panel it would be better just to send the energy into a heater for the motor to keep it warm. But 5W for most of the charger panels isn't worth the money I guess.

I do understand what you are saying, it would actually need a solar panel to output >=244.8v if that is what is at the poles. So like panels on half my house? ha

Stating there are now solar powered recharge stations for cars at buildings, etc but they put out a lot of current which would require a large number of panels. The stations charge the complete battery via the cars electrical port.

How many panels, don't know. Solar cell output is DC, would also need something to boost the voltage to 244.8v but what don't know.

Can always surf the internet for posts on solar cell charging stations and email or write the authors for more info.

Your best bet is to determine if the car can be wired to charge via the 120/240v electrical system at the house with some kind of interface between the house power and battery.

As you imply, solar cells are not cheap.

Try asking at the Toyotanation, Prius section. They seem to know about battery charging, etc.

I guess not, your charging unit must pattern the amphere and voltage of your battery needs.

have not seen your post neither at toyotanation, nor at Green Hybrid, which are 2 main TCH forums.
1st time I hear 12V battery, which is auxiliary battery on TCHs, is a backup battery for NiMeH one. Best I know, it's always charged from engine, even in reverse mode, and if NiMeH one goes discharged, that's it, it's special recharge procedure and vehicle is not drivable.
Keep in mind, 12V battery is deep cycle one, and is not charged the way regular ones are.
They sell plug-in add ons for Hybrids, but most agree that gain is so minute that it's cost prohibitive, unless you really want to...