adding extra 4kw battery for more than double plug in miles

Don't you mean 15AH*3.6V=54WH?

 

Where did you find the battery chemistry specified? From Wikipedia, the lithium-ion battery chemistry with the lowest voltage is 3.3V. The OEM cells are 3.7V.

I was wondering about that. 3.6V is the highest voltage, so I think taking the average of 3.4V between the rated and float voltage is the most reasonable and that works out to 3.876kWh. Furthermore, I don't see anywhere that states the Ah specification is for total as opposed to usable capacity.

As for simply putting the packs in parallel and discharging/charging them simultaneously, I don't see how it is done. The battery pack voltages don't match. The OEM battery pack is 207.2V (56 * 3.7V) and the PIS battery pack is 258.4V (76 * 3.4V). Maybe PIS battery pack is keeping the OEM battery pack charged. This would allow the PIS battery pack to discharge at a slower rate and increase the Ah that the battery could supply.

 

It "stiffens" the Toyota pack, the control they show is a simple relay, they don't use a DC-DC converter aka "Engineer"

They may not even have tried it yet, more than likely...

 

interesting, I came across this one:

Amazon.com: 4KWH Solar Powered Backup Generator and Hybrid Plug-in Add-on Kit: Patio, Lawn & Garden

 

It looks similar to:
Enginer Portable Power Station | Enginer

 

lol, doesn't look like it fits into a PIP. but their description assumes it's installed in a prius.

Solar Powered Generator for Residential Property By using solar energy to charge Lithium battery, this system can be used as residential backup power generator. Solar panel size is 50W and AC inverter is 600W. Improve your MPG's By using electricity from the grid, your gasoline consumption will be reduced significantly. Fuel Economy improvement is between 40% to 100% in city driving. The cost for the electricity cost around $0.40 per charge. It is equivalent of $1.00/gallon of gasoline. Easy Installation There are only two low voltage and two high voltage wires to connect. It takes four hours for professionals to install. Most automotive savy customers with electrical background can do it themselves in eight hours. Affordable Our solution is the most cost-effective in the world. It is only a fraction of our competitors'. Our 4KWH kit cost is only half of Toyota 2012 Plug-in option and it has 50% longer range. GE Money finance is available for installments. It qualifies for 30% Federal Energy Efficient Property Credit. Preserve OEM Warranty This non intrusive add-on keeps all original components in place and doesn't void original warranty. Universal Our solution is able to be installed any hybrid vehicles, including Gen1/2/3 Toyota Prius, Gen1/2 Honda Insight, Ford Escape Hybrid, Ford Fusion Hybrid, Lexus 200/400H, etc . Contact us for detail installation instructions. More Details are available at Enginer | Solar Powered Prius Plug-in PHEV Conversion Kit with Lithium-Ion | Hybrid

 

I think it's just their Prius add-on battery kit with an additional inverter to provide AC power and mounted on some wheels.

Now that I think about it, I've heard that there are government incentives for batteries for solar power. Maybe this is a way to get some of that money by tacking on the solar panel option.

 

Don't need inverter, because I live in a high rise apartment. I just want the kit.

 

they're only 4 miles away from me. So maybe I'll take an EV powered trip over there

 

their 4kw conversion kit is the same price.

Enginer | Prius Plugin PHEV Conversion Kit with Lithium-Ion | Hybrid

 

Your numbers are a bit off here as well. kW is a unit of power, kWh is power used over a fixed period of time. The usable portion of the battery pack is indeed about 3.2 kWh. However, the charging inefficiencies means that it actually takes about 3.8 kWh from the wall to charge up that 3.2 kWh. You seem to imply that the PiP only can use 2.8 kWh from it's battery pack because of charging inefficiencies.

The PiP's internal charger will only pull a maximum of 2.2 kW from the wall at 240V. Or about 9 amps. I don't have a kill-a-watt meter, but I believe that the most it will pull at 120V is about 10 or 11 amps for around 1.2 kW.

Your numbers are a bit off

 

My Kill A Watt says 11.79 amps average



The PiP's internal charger will only pull a maximum of 2.2 kW from the wall at 240V. Or about 9 amps. I don't have a kill-a-watt meter, but I believe that the most it will pull at 120V is about 10 or 11 amps for around 1.2 kW.

Your numbers are a bit off[/quote]

 

Since you don't seem to trust me, let me provide some references. From Wikipedia:

Reversing that, means that energy is power times time.

I've measured using a Kill-a-Watt at the plug the amount it takes to charge from empty and it is about 3.2kWh. Tracksyde measured it as well: First day with my Prius Plug-in | Page 4 | PriusChat
It's also discussed here:
New PiP Owners...More data please!!! | Page 2 | PriusChat
I've verified that the kWh reported by the car is about 85% of the the kWh measured at the plug over multiple charges (to get more significant digits since the car rounds to the nearest integer).

The car reports the power going into the battery, aka after losing 15% to charging inefficiency. The amount being pulled from the plug is the what the car reports dividied by 0.85.

No, you've got the power going into the battery mixed up with the power being pulled from the plug.

 

I sit corrected, yet again. Though I think Kilowatt hour - Wikipedia, the free encyclopedia is a better explanation of electric power, which is more appropriate here, than the physics one.

 

I can get 4kw battery installed free for $3495 at Engineer.

I have a 2012 Plug In Prius. I would like to add a supplemental 4kw battery pack to my existing battery. Can you give me details on parts needed, and cost?
Sun, Sep 9 2012 9:13am - Jack Chen
The same kit can be installed onto PiP. The cost for 4KWH kit is $3495.

We can provide free installation ($500 value) at our Troy, Michigan facility. You also save shipping fee of ($200) if you install here.

 

Wow, now that is alot better price! I like this alot. And to get free install and save the shipping, I would drive over there from my place and stay for a day overnight to take that deal. Are you going to consider it?

Id love to hear some real world feedback on the charge time increase and the actual EV distance increase. If I could get 20 miles going at a decent pace, It would really make it worthwhile for me as i would probably never need to run ICE ever except for road trips.

Dan

 

only one drawback, their battery pack has to use their charger which is tapped into my port on my PIP. So, I don't know if that would work b/c two chargers would probably exceed the 15amp limitation of my outlet.

 

and their facilities is only 1.6 miles away from my apt.

 

Does the $3495.00 include the charger? Because my car already has a charger, so I don't need to be charged for the charger. I took a dry run out to your address yesterday, so you do the installation out of your house? What financing options are available? I have an Amazon account and noticed I can get 12 months no interest if I purchase your product through them. I would prefer a longer free interest payment plan.
Sun, Sep 9 2012 9:44am - Jack Chen
BlankApplication.pdf (0.8 mb)
Yes, it includes a charger. Since our pack is low voltage 48V, it can't use the OEM traction battery charger. But we can tap into the same J1772 charging port so that you don't need extra plug.

We have a shop at 330 E Maple, Suite M, Troy, MI 48083 where we do the installation and service.

Attached is a GE Capital financing application. If you are qualified, they provide 12 month interest free financing if it is paid in full within 12 months.

 

But if you are in CA, you are forced to buy the 5 year warranty due to CARB, so it's $4495 and not that much cheaper that PIS.

I think the unit is also much larger, since it includes a charger and possibly a DC/DC converter. It's not clear to me if there are benefits to having these additional components to make the tradeoff of space worthwhile.