Costs of a PHEV system.

[Cheap!]

Here is a copy of my email that I sent to my PHEV group today.

"
Well guys I unfortunately have to post that my pack of 20 Best Battery EVP20's is DEAD! Each battery has bulging on each side. You can easily see the protrusions centered on each cell, of each battery. I have not pulled them yet and I will take some readings on them when I do. They are not leaking. I will take pictures of them to post online later.

My pack cost me $900 and I got 300 cycles out of it. (I was lucky because most people would only get 200 cycles.) That is a battery cost of $3.00 per cycle. I got between 15 EV miles per charge with new batteries, and 6 EV miles per charge at the end of its life. That is an average of 10.5 miles for each cycle. That means my battery cost was $3.00 for every 10.5 miles, or a "battery only cost" of "$.285714" per EV mile.

Then there was the electric cost of about 60 cents per charge. Texas rates for wind energy is "15 cents per Kwh." That works out to be an additional "$.057143" per EV mile. These two figures bring the sub total of "Cost per EV mile up to, "$.342857" per EV mile. That doesn't even include the cost of all the other components of the plug-in system.

In the standard unconverted Prius I get 50 miles per gallon. At $4.50 per gallon, that is just 9 cents per mile. Meaning the cost of operating my Plug-in conversion is 25 cents more per mile than a standard Prius. However, I still am happy to use less Foreign Oil, keep our air cleaner, and I still believe Plug-In cars are a great next step for our nation to pursue.

We have to get the cost of electric storage down...and I mean way down. I estimate that the cost of these batteries would have to come down to $103.50 for the entire pack to be equal to the cost of the fuel consumption it offsets in a standard Prius. At this time I do not think that lead acid batteries can stay alive long enough to offset their cost. I am now looking for alternatives to use in my next pack."

I think I gave it my all, and I hope others can use this base to figure out what the costs and returns are for a PHEV system.

If you do the math on "ANY" system you might be considering, I believe you will see it to be more financially expensive that just leaving the Prius as it is. However, what is the cost of using so much Foreign Oil, and what is the cost of Clean Air? For some like myself it is not about the money!

Let’s say you could get 80 miles per day at 100mpg, by charging twice a day every day, when you normally get 50mpg.
That is equal to 40 gas free miles per day. And now let’s say your pack will last, oh I don’t know, lets use about three years so that is 365 days X 3 Years X 40 Miles, or 43,800 gas free miles.
To travel 43,800 miles in a 50mpg Prius at $4.50 per gallon, that would cost $3,942. So you would have to consider if it is worth, “for you,” to get a PHEV pack that costs more than $3,942.

For me it is worth it!
However I can’t answer this question for you. You have to do the math for yourself.

[TheForce]

Sorry to hear about your dead batteries. I thought they would have lasted a little longer than that. Is this the first someone actually reported replacing the lead acid batteries in a plugin? Since there are a lot more people out there with these led acid conversions and a lot of them installed theirs before you did I'm just wondering if the others replaced theirs yet or are still running them. I'm curious if they are sticking to lead acid and sticking with replacing them every 300 cycles or so.

This was really the main reason I was waiting for Hymotion. I did not want to be replacing batteries every year or so.

Hope you get your PHEV back up and running soon.

[Cheap!]

I know of several others who have had to replace their packs. I think I'm the only one on Priuschat.com who has done it. You can check the Calcars.org website and they say 200 cycles.

Knowing that and using the average of 10.5 miles per cycle you can figure how many miles you can get out of a pack. I was lucky and my pack lasted longer than it should have. I had a lot of fun over the past two years playing with this technology. I loved the “gas free weekends” while still driving my family to the movies and restaurants. I am still a supporter of Plug-in cars and I will most likely build my own Lithium-Ion pack, even knowing that battery management of so many cells is a PITA.

The point is, if “we” want this technology to take off, so we can get off of foreign oil, people need to know what to expect. Otherwise, we will just have a load of people out there talking bad about Plug-in Hybrids. The truth is They Work. Now the next step is to bring down the cost.

A standard Prius cost about 9 cents per mile when gas is $4.50 per gallon and you get 50mpg. Using my 15 cents per Kwh of wind energy, to get one charge cycle of power. (60 cents to go 10.5 miles, a.k.a “5.7 cents per mile”) That only leaves 3.3 cents per mile for the rest of the system.

That does not leave a lot of room to make up the cost of the system.

Just like with solar panels making the car efficient first makes more sense. However, I am not too fond of giving my hard earned cash to buy gas that gets burned in my engine and thrown into the air for all of us to breathe.

[bestmapman]

Hi Jim,

You may want to touch base with Steve Woodruff. His web site is autobeyours.com. He has built an Li-ion PHEV.

[Cheap!]

Yes, Steve has built one, and the real problem with Li-ion is lack of a reliable BMS. We won't know how good a BMS system is until the pack finally fails. IF you make the Li-ion pack too small you will really shorten the packs life. If you make it too big, you have the problem of managing those extra batteries and up the cost of the pack. Since the Prius already gets a great gas mileage it is very hard to justify “ANY” PHEV conversion in terms monetary benefit.
In other words, you will buy less gas, but you will spend more over all doing so.
I just want people to understand that before they jump onboard thinking they are going to save money.

[dmckinstry]

Originally Posted by Cheap!

Yes, Steve has built one, and the real problem with Li-ion is lack of a reliable BMS. We won't know how good a BMS system is until the pack finally fails. IF you make the Li-ion pack too small you will really shorten the packs life. If you make it too big, you have the problem of managing those extra batteries and up the cost of the pack. Since the Prius already gets a great gas mileage it is very hard to justify “ANY” PHEV conversion in terms monetary benefit.
In other words, you will buy less gas, but you will spend more over all doing so.
I just want people to understand that before they jump onboard thinking they are going to save money.

For those of us who want to convert to PHEV, saving money is obviously not the issue. It's to become independent of petroleum products for transportation. Obviously that isn't completely possible, since we need lubrication products, etc. Of course, I'm using synthetic now. Except for spinning up the engine for lubricating it, I hope my engine never turns on for local driving. I'll find out in November or December. Our electricity is under 6 cents/kW-h, but I eventually hope to put photovoltaics on my roof. I wish Washington State would give the same sort of incentives as California does.


Dave M.

[Cheap!]

Dmckinstry,
Yes I have been using Clean Domestic Wind Energy and I would like to get PVs on the roof of my home. I rebuilt my PHEV kit to fit completely under the decking in the trunk, and there is no cutting at all to the fabric trim pieces in the trunk so you can't even tell the PHEV pack and charger are there. I priced it at $6,000 installed complete with heavy duty springs, but I have not had many takers because I insist on telling everyone that it costs more to operate a PHEV then it does just to operate the Prius as is. I still had a few takers though.

The charger puts out a lot of heat so I think i would recommend that someone who can, just keep their spare and leave the charger at home so it is always out side of the car and the pack stays cooler. That won't work for everyone so fans kick on when you plug-in the car.

Now if we could just get the price of energy storage down!

[miscrms]

This is definitely the downside of the cal-cars PbA method. The upfront cost is great, but operating cost is high. I still think a balancing charger and not running the batteries all the way down to charge sustain mode would probably do wonders for extending the life of the PbA pack, but there's no proof of that yet. I'm seriously torn between testing that theory or going with the Nilar NimH batteries when/if I ever get the time and money together to do my conversion.

If you haven't checked out Nilar yet, I would give them a good looking at. The pressure sensors make the BMS a lot simpler, and the 9Ah/24V pack size means you only have to run 2-3 strings of 10. There is also a cal-cars subgroup working on using these batteries in the cal-cars platform and they are working on an open source BMS and charging scheme.
Nilar - a new way of packaging energy

These guys are also working with Nilar:
Plug-In Conversions and Nilar Team Up

Even for NimH I still like the idea of multiple isolated chargers. That way you know you are always getting a full balanced charge. If something like the ones below proved to be appropriate you could have negative delta-V termintation and temperature protection on each individual pack for $30 per module or $800 for 3 strings. You could also probably work in a failsafe using the Nilar's pressure sensors, and you'd want some kind of lockout to make sure the pack is disabled if any one charger failed.
Universal Smart Charger (1.5A) for 19.2-24V NiMH/ NiCd Battery Packs with Tamiya Connector - CHUN-2420

Rob

[Wildkow]

Since the BMS is a high dollar piece of equipment is there a BMS/Charger system out there that can do PbA, NiMH, and Li-Ion. That way I can build my system with the cheaper PbA's and wait for better batteries to come out to replace them later?

Wildkow

p.s. BTW which PHEV forum do you belong too?

[aminorjourney]

Hi Cheap,

I saw your posts. So it was you who had the problems. EEEEEP!

I'm going with the method as currently in development with the parallel OEM packs and BMS + from HybridInterfaces. I'm just waiting until all the prototypes have finished extensive testing.

I totally agree with you on the cost analysis. We need to make this more cost-effective or people just won't follow these projects on. One of the things that have caused problems in the UK EV world is cheap, sub-standard vehicles such as the G-Wiz and extortionately expensive PHEV conversions. Neither does any good for the technlology's publicity.

Perhaps we can hope that CalCars considers building a technical foundation, funded by donation from public bodies, interested enthusiasts and possibly even big business to produce a viable cost-effective solution.

Of course, big companies such as Toyota and GM are the ones who will make PHEV viable if they so choose to do so. Yes, we can do it now but of course the cost and DIY elements will scare people off. Here's hoping that someone can help change that. Maybe a foundation may just work?