I want to charge the battery that comes with the Prius.

[richard schumacher]

Again, the auxilliary battery removal and installation is free. You can do it yourself in less than 30 minutes. Honestly. You must mean the Main Hyrid battery. But even that installation doesn't cost near 10 thousand dollars.

*That* guy was talking about secondary traction batteries added in parallel to the original traction battery, either to increase the electric-only range or as part of adding plug-in capability. That does cost upward of $10,000 and is not economical except for fanatics.

[richard schumacher]

I'm beginning to think the Chevy Volt series hybrid method is the better way, since you don't need the weight of a transmission

Now there's a question: what transmission does the Volt use? A conventional fluid-drive automatic, or does their drive motor operate directly over the entire speed range? I'd bet a dollar that GM execs would rather have their engineers commit suicide than license Toyota's HSD and adapt it for use with two electric motors only.

[miscrms]

Originally Posted by Dan45

I want to charge the regular battery that comes with the Prius so I can start off in the morning with a full battery. This shouldn't be too hard to do. I was thinking maybe a switch to disconnect the battery from the car and than into the charger. A trickle charger could be very small and automatic so it wouldn't over charge the battery.

Or the charger could be connected to the battery without disconnecting it from the car. This would allow it to keep the water warm and to keep the 12 volt battery charged.

I can see that the main problem would be driving off with the car still plugged in.

Does any company make such a thing?

The HV battery cannot be externally charged in any cheap/safe manner that I am aware of. If you could find a 200V trickle charger it wouldn't matter. Whatever charge was put into the battery would be ignored by the battery controller, and it would still report the SOC. As long as its reporting the same SOC, the HV controller will not draw any more power from the battery. In fact, it will probably try and charge the battery potentially overcharging and damaging it. You need a charger with 242V or higher applied while the car is active in ready mode to get the Battery Controller's attention. At this voltage the charge current must be carefully controlled and SOC carefully monitored. If you leave this high a voltage on the battery for any length of time it will explode and catch fire. And yes, its happened.

There are devices that might be able to do this job, such as the Manzanita Micro Charger combined with a CAN-View to monitor SOC and terminate charging. But then you're looking at several thousand dollars worth of equipment for a very minimal benefit (maybe 1 mile EV, or 2 miles highish mpgs).

If you are serious about wanting a plug, the cheapest option right now is the Cal-Cars Priusplus open source DIY PbA conversion at ~$3-4k for 10-12 miles EV or ~20 miles at 100+mpg. Downside is you will need to replace the PbA pack every year or two. The NimH Cal-Cars conversion is less mature, but should give 15-20 miles EV, or up to 30-40 miles 100+mpg for about $7k with excellent battery life. After that you might as well get the Hymotion Li-ion pack installed for $10k with a 3yr warranty.

PriusPlus - EAA-PHEV
Hymotion :: Enabling the new generation of hybrid owners to maximize their fuel efficiency

Be advised, the traction battery in the Prius can put out 200+ volts and hundreds of amps. This is more power than is available in most houses. It can make an arc-welder look like a toy if not respected.

Rob

[miscrms]

Originally Posted by TransferFunction

archae86,

Like IC engines, your body muscles are only about 25% efficient in converting the calories into useful motion, the rest going to heat.

I'm beginning to think the Chevy Volt series hybrid method is the better way, since you don't need the weight of a transmission, and the complexity goes down for customization (more modular separation of engine and battery charging there). The Prius parallel hybrid arrangement is a complicated torque engine/electric blending circus along with battery charging strategies that don't make it easy to tinker with as much. I've heard the auxiliary battery installation jobs run around ten thousand or so. Ridiculously overpriced, but probably necessary.

Not sure what you are getting at. The Prius doesn't have a transmission either. Depending on how you look at it I'd say the HSD has ~6-10 moving parts, excluding the ICE of course. Serial hybrids have an advantage in that the ICE can run at a true peak efficiency steady state almost all the time. Parallel hybrids have the advantage of being able to run off the most efficient power source at any given time. IE if the battery temperature is such that the efficiency will be really low (or the battery could be damaged) you have the option of running of the ICE. Given the virtual CVT nature of the PSD, you can also run the ICE very near to peak efficiency most of the time except in those type of circumstances when you may still be better off. As far as batteries go, I'm not sure why you think the battery in the Volt will be any simpler. If anything Li-ion has even more quirky challenges to deal with.

Toyota Prius - Power Split Device

Rob

[TransferFunction]

miscrms, Excellent explanation there. The PSD is essentially a torque summation device, summing MG1 + MG2 + ICE torques. I think you hit one of the keys to getting better efficiency out of an ICE: operate it at a very narrow range of RPMs only. Then, you won't need a complicated ICE, since variable valve timing/lift is not necessary, and the intake manifold is tuned for one RPM. When an ICE doesn't have to operate over a large range of RPMs, you can raise the compression ratio (increasing efficiency) a little. You can probably get a 15% efficiency gain just by operating the ICE in its sweet spot all the time. A series hybrid doesn't even need a PSD. The ICE is only on the charging circuit with its own small generator attached. Then you just need one electric motor attached to constant velocity joints to the front or rear wheels. I do wonder if routing the power through the batteries all the time means there are times when the battery cooling fans must run more. Don't know how that will pan out. Should be OK, looking at all the pure-electric prototypes out there, and observing the series hybrid trains & buses out there now.

Since you live in Phoenix, you could take Advanced Propulsion at ASU Tempe like I did back in '89 while working for Honeywell Avionics.

[k2technical]

No, I think he WAS talking about the high voltage battery! and the posts were interesting about it. Building a 240 volt DC charger that would not overcharge the high voltage battery pack is expensive. That is because of the regulator and isolation transformer required. When the new plug in hybrid comes out, it will have that ability with all the safety concerns worked out. Maybe then Toyota will offer the modification for the EV switch, new battery pack and high voltage charger for the rest of us.....

[patsparks]

Originally Posted by TransferFunction

patsparks,
That is Watt*Hours, not Watt/Hours.
And remember the usable energy in gasoline in an Otto cycle gasoline engine is about 20%, so multiply times 5. Otherwise, your conversion constants were good.

Thanks teach.

The Prius isn't fitted with an Otto Cycle engine but an Atkinson Cycle engine which extracts about 40% of the energy from the petrol to do useful work so you need to multiply by 2.5. I knew about this and was waiting for someone to pick me up on it. Well done.

I still don't think it is worth risking damage to the battery for the small savings. It also needs to be considered that any charge system would have conversion losses and the cost, both economic and environmental of the electricity generation must be considered when working out any savings.

[FL_Prius_Driver]

Originally Posted by k2technical

No, I think he WAS talking about the high voltage battery! and the posts were interesting about it. Building a 240 volt DC charger that would not overcharge the high voltage battery pack is expensive. That is because of the regulator and isolation transformer required. When the new plug in hybrid comes out, it will have that ability with all the safety concerns worked out. Maybe then Toyota will offer the modification for the EV switch, new battery pack and high voltage charger for the rest of us.....

Just for info. You can go way back in history and find Statultra did a nifty trick of pulling the battery safety plug and charging each half of the traction battery using probably less than $100 worth of parts and a regular AC outlet.