PHEV Recuperation Calculator

[cproaudio]

Edit: New version on post 13

Many hybrid owners think that they can recuperate the cost of PHEV kit. The reality is that you can't. People convert because they want to own a plugin hybrid, not so that they can recupe the cost. It's the same logic as people mod cars to go fast or raise 4WDs. They don't race everyone at every light or go off roading every day. They did it for the sound and the looks. Anyways, this is my PHEV Conversion Kit Recuperation Calculator. This gives you some idea how long it takes to recuperate the cost of the kit. Even if you don't have PHEV kit, you can still use it to calculate cost and mileage of none converted vehicle. If you find any flaws to any formulas, please let me know. Have fun using it.

Notes from the calculator
1 Current configuration is based on a Gen III Prius with Enginer 4KW kit purchased from an authorized dealer.
2 Price per KW varies greatly based on type of plan, time of use and total usage per month. Input the amount per kw you think you're paying on average
3 Price per gallon of gasoline is based on US gallon. If you're using liter or Imperial gallon, input consistent unit of measure throughout this calculator. Do not mix US gallon and Imperial gallon and liter
4A You can input the total amount you paid for the kit or itemize each charges. Please use the same currency throughout this calculator.
4B You can input the total amount in rebates you're expecting to receive from the government. Please use the same currency throughout this calculator. 5 Input your calculated MPG before the conversion. I realize that many of you use l/km. You can use the link below to convert l/km to MPG
l/100km to MPG / Litre / MPG / MPG to l/100km / Liter / Convert fuel efficiency - eForecourt.com
6 Input your actual or estimated MPG after the conversion that you think you can achieve. If you don't know, use 170% of your stock MPG.
7 This is the estimated mileage driven on electricity without using gas. It is the improvement the PHEV kit has made on your vehicle per gallon.
8 This number is hard to calculate. This is your estimation on how much electricity it takes to drive your vehicle 1 mile. The lower the wattage the more efficient the car is. For reference, Leaf takes 340 watts to drive 1 mile, while Volt takes 360 watts per mile.
9 Enter your PHEV's battery capacity.
10 Enter the estimated miles you drive per day. If it varies, enter a number to reflect your weekly miles, monthly miles or annual miles. Enter only the daily miles you drive. If your miles vary, enter any miles that reflects your actual weekly, monthly or annual mileage.
11 Battery packs degrade over time. Enter a percentage that will reflect the actual blended miles driven when your pack has been depleted. This will give you a good estimation of how much usable KW your battery can take and also gives you an estimated EV range. EV WattsPerMile will change this.
12 Due to conversion loss, there's no charger on the market that's 100% efficient. You can ask the manufacturer for the charger's efficiency rating.
13 This estimates how much power going into your battery pack and how much power actually made it due to conversion loss. Even though you have a 4KW pack, it may not deliver 4KW of power. BMS high voltage cutoff can prevent rest of the pack from fully charged if 1 cell triggered the HVC. LVC can prevent your kit from working if 1 cell has depleted while other cells still have power. Balancing also removes power from each cell.
14 To achieve the high MPG, your batteries may be depleted before you've reached your destination. This estimation is to show how many charges you must make in order to drive the miles you want and achieve the mileage you want. You have to round this number up. 1.1 charge = 2 charges
15 This shows approximately how many EV miles and how many miles of blended driving your kit is capable based on the capacity of your battery pack.
16 This shows approximately the energy usage based on the stock MPG and the PHEV improvements has made.
17 This shows approximately how many miles traveled on EV and on gasoline. This is based on the improvements the PHEV kit has made over stock.
18 This is how much gasoline you've used before you converted to PHEV
19 This is how much you've spent on gas before you converted to Plugin Hybrid
20 This is how much gasoline you're using after you've converted to PHEV
21 This is how much you've spent on gas alone after you converted to Plugin Hybrid
22 This is how much gasoline you've saved after you've converted to PHEV
23 This is how much money you've saved on gas after you've converted to Plugin Hybrid
24 This shows approximately how many kw used from the wall to charger to battery pack based on the EV miles driven and the EV wattage used per mile.
25 This shows much you've paid on electricity based on the kw used. The cost has been adjusted to offset the charger's efficiency.
26 This is the total cost when combining the cost of electricity and gasoline. This is how much you pay in energy after PHEV conversion
27 This is the bottom-line total savings after PHEV conversion
28 This is how long it takes to recupe the cost of the PHEV conversion kit


Edit: updated with Version 2. Now includes charger information and charge time.

[Flaninacupboard]

Good calculator. I get about 4 years, depending on whether i think petrol is going to get more or less expensive. i'm keeping this car until 2020 so that's fine by me.

[cproaudio]

How much do you pay for electricity?

[sub3marathonman]

That is a great analysis that cproaudio came up with. The only thing I would want to check is the watts/mile. I think the enginer kit will supply much less than 250 watts/mile driving blended 57% gasoline /43% electric. From the Hymotion kit, I have found it takes about 235 watts/mile going purely electric, and less than 200 watts/mile driving "blended." That is only the figures that I have seen.

[cproaudio]

did you download the calculator? you can change that number to cater your driving style. for my driving style I I've estimated that a mile takes 250 watts.

[SageBrush]

Per EPA charging has about 20% energy conversion losses in both the LEAF and the Volt.

The SS looks like a lot of work, I admit to being lazy and think of it this way:
A kwh is optimistically good for 4 miles of driving. If I buy a 4 kwh pack for $4000 and recharge once every day for 10 years, my electric miles cap cost in pennies is 400000/(16*365*10) = 6.85 cents/mile. Electricity cost brings me up to 10 cents/mile, so breakeven with petrol assuming 50 mpg is $5/gallon.

A little more accurate would be to assume only 80% of the pack charge is used, so breakeven jumps to $5/.8 = $6.25 a gallon petrol.

As an aside cpraudio, if you put your SS on the web as a google doc changes will be much simpler for you and your fans will not have deprecated versions.

[cproaudio]

I totally forgot about the cost per mile. I'll put it in the next version.

[2k1Toaster]

I have recently learned and confirmed that some states (like my own) offer extreme rebates for PHEV conversions.

If I get an engineer kit installed, I will be out $0.
If I get a Hymotion kit installed, I will be out less than $2000.

So obvious YMMV for state rebates.

[SageBrush]

^^ Wow. Colorado is also generous, although not Santa

[mrbigh]

cpraudio, thank you for making the chart larger and easy to read in your first post