Archive for the PHEV Category

PHEV Prius gets a new POWER SOURCE

Posted in PHEV on May 18, 2009 by wizbandit

I finally have Prototype 1.0 of my DC-2-DC converter installed.  This converters runs off 12VDC nominal which allows use of conventional battery charging with inexpensive off-the-shelf chargers.  It’s a basic, simple 1000 watt converter I came up with using inexpensive parts.  The most expensive part is the 1000 watt Toroidal Transformer seen in the picture.  So far testing is going well, the converter only supplies 4-5 amps into the OEM Traction Battery so it does not function the same as the setup I had using 20 small 20Ah Pb batteries. The main thing is it IS transferring power from the added battery pack to the car assisting the ICE using electricity which is the main reason for the PHEV conversion.


I still have some more tweaking but it works using the CAN-View system that was installed with the 20 battery setup.  For testing I’m using two DEKA 55Ah AGM batteries.  The final setup will have six of these.

Hacking the Schumacher SPEEDCHARGER for PHEV & EV use

Posted in PHEV, Tips-N-Tricks on August 12, 2008 by wizbandit

    If you find any of this information useful please leave a comment.

My project for the past few weeks has been hacking into a nifty little battery charger manufactured by Schumacher called the “SPEEDCHARGER” model SC-600A.  A fellow EVer told me about this AGM charger he bought from Wal-Mart.  Now the last place I would look for a charger for AGM batteries was at Wal-Mart.  I bought one and when I got home I tore it all apart.  Later in this report I will explain its operation in great detail.  I was excited to find a simple 3-stage battery charger in such a small package, all the logic was on a 3 inch square PC Board.  What I have done is created a 320VDC supply using the MPU in this little charger to control the power into a 20 battery (12V each) PHEV Prius pack.  It would also be easy enough to modify it to work with any number of 12 volt batteries up to 20, like 12 for a 144VDC EV pack or 10 for a 120VDC EV pack.


Here is the PIC controller LED board, this is the brain of the charger.  All I had to do is come up with a voltage divider that divides the 20 battery pack by 20 and feed this voltage into the control line. (It’s a bit more complicated than that but simply put.)

Here is my “Bread Board”, yes, literally mounted on a piece of shelf board.  I hacked up an old 200 watt AT power supply, stripping out all the LV components leaving just the HV capacitors, rectifiers & chokes.  The old AT power supplies used 320VDC, the way they got this was on 115V it used a voltage doubler, on 230V it just fed the bridge rectifier across the two series connected high voltage capacitors.

The SC-600A has settings for 6 volt or 12 volt as well as 2amp, 4amp and 6amp.  It’s kind of neat how they control the current as there is no current shunt in this unit as they don’t measure the current, they caculate it from the Pulse Width Modulation (PWM). I’ll detail this later on.


Here is the finished Version 1.01 PHEV 260VDC battery charger.  I mounted the original right onto the old AT power supply.  Not bad for less than $50 for a 800 watt charger.  Version 2.0 will use a 450 watt ATX supply with the hope of a bit more power.


STOCK SC-600A – Theory of Operation  (Check back later!)


Voltage Doubler – How it Works (soon!)


EV Modified SC-600A – Modification & Theory of Operation  (Check back later!)


Interface Circuit Board Schematic  (Check Back Later!)


Terminology Used in this article (In Progress!)

[The Power Brick] – The Constant Current power supply used in the SC-600A, it measures 5.5″ x 3.5″ in size and mounts in the bottom of the case.  This unit has two separate sections as do most switch-mode power supplies.  The HV side has a power MOSFET controlled by the AP3845CP current mode PWM integrated circuit and a 14V house-keeping power supply.  The LV section has the 6AMP @ 15.5V output and a 14V house-keeping supply as well.  There is a 6V 3-terminal regulator that supplies power to the MPU PCB.  There also is a power resistor/12V zenerdiode supply for the 12V 1.5″ case cooling fan.  One odd thing about this is as the load on the output changes so does the speed of the fan, the zener just caps the voltage at 12V.  This unit is either ON providing about 6 amps of current or OFF. The way they get 2 amps & 4 amps is the MPU PCB itself uses PWM through an opto-isolator that turns the power brick ON and OFF.  By controlled ON/OFF the unit can effectually provide 2 amps or 4 amps of current into the battery.  In the 6 amp mode the MPU PCB just holds the power brick ON. This all happens until the MPU CPU needs to switch into Constant Voltage Mode when it uses PWM to hold the voltage constant.  Think of it as “pulsing” a PWM power supply On & Off to maintain a constant voltage. There is a relay on this board that is controlled by the MPU PCB, the reason for this is two fold, the MPU PCB checks for proper connection (6V or 12V battery) and correct polarity before sending power out to the cable clamps. This also prevents “sparking” of the clips while connecting them igniting nearby hydrogen gas causing an explosion resulting in sulfuric acid rain on all nearby persons.


[The MPU PCB] – The brains of this charger uses a simple PIC chip programmed to charge AGM type batteries.  The algorithm used seems to favor the AGM as there is no selection button as on the “Big Brother” Schumaker SC-1200A model.  I don’t see a problem charging flooded batteries using AGM algorithms, they still will charge up fine just a bit slower.  You will destroy an AGM battery if you charge it like a flooded battery. There are only 5 wires connecting this to the Power Brick, Ground, +6V IN, relay control OUT, Battery Voltage Sense IN and Power Brick ON/OFF (PWM).    (to be continued…)

[Chip Bag Clips] – Recycle everything, use them to hold chip bags closed. You don’t want up to 320VDC dangling on these so they get replaced with a 50A Anderson Power Connector.

PHEV Prius gets finishing touch

Posted in PHEV on July 21, 2008 by wizbandit

After charging the PHEV with the power cord hanging out of the trunk I finally got ambitious and located some bumper-mount power inputs.  They are made by MARINCO and cost around $12 each.  They mount in a standard 1 1/2″ electrical conduit hole so being an electrician by trade I just happen to have a Greenlee punch that size. The metal lock-nut that comes with it is a cheesy cast style that I replaced with what is known as a RIDGID CONDUIT lock-nut.  It is a bit larger and stamped which makes it a bit stronger.  It was a bit difficult to get the lock-nut real tight being there is only room enough behind the Prius bumper for your hand so in retrospect the next time I will braze two 1/4-20 nuts onto the lock-nut to use as thumb-screws.

I used a standard 4″ square electrical box cover I punched a 1 1/2″ hole in as a backing plate but the next one I think I will use a 4″ octagon box cover instead.  I had to curl the top and bottom of the plate to match the curves in the Prius Bumper, the octagon box cover should be easier to bend.  The lock-nut on the left is the one that comes with the inlet plug.  There are three places on the plug if you want to use screws you can drill a 1/8″ hole and use SS screws.  Be sure to mount with the GROUND terminal UP as there is a drain hole inside the connector to let water out.  What I did, after fighting to get the lock-nut tight was to carefully drill & tap the three screw places right into the metal backing plate, tapping threads to 6-32 and using 6-32 x 3/8″ SS screws to hold the input connector solid.  This I found out taps through the lock-nut and keeps it from turning as well.


Now with copper prices so high I wasn’t surprised when I went to get a cord for the Prius to find 50 footers around $25 for the cheaper ones and up to $50 for the “commercial grade”.  All were either ugly orange or black/red, yuk. BUT!, hear this, around the Holidays most stores have GREEN extension cords!  I ran onto a big boxful left over at Home Depot, #14 AWG, three wire, 15 amps cords 50 feet long for $12.95 each, can you say “scoop”?.  The only problem they had 3-plug ends on them which required cutting it off and installing a standard female 15A cord cap.  Damn, the price on those things HAS SKYROCKETED!! Don’t even go look at the “twist-loc” connectors, I saw some up to $50 each!! The “Pro-Grade” 15A female cord caps were over $5 and most closer to $10, BUT!, wait, Wal-Mart to the rescue!, Leviton 15A Pro-Grade cord caps UNDER $4 EACH blister packed!! Don’t even bother going to the Wal-Marts around me because they are all gone 🙂

I have been replacing batteries this month, the 18AH MK brand are being replaced with TOYO 20AH units.  The TOYO were only a few dollars more than the MK’s.  I buy them from WEST FLORIDA BATTERY in Port Richey, FL, a family owned & run battery business, ask for Bob, tell him plug-in-Prius-Jim sent you!  I thought I was suffering early battery failure but when I calculated the cycles on these from 02/15/2008 to 06/15/2008 with 1 to 4 cycles per day I estimate over 300 cycles on these batteries!  Weekdays usally one with my son driving to school and home with maybe another for an evening trip to the store, all these add up if you include maybe 3-4 for each weekend day.  Here is the new TOYO with the Zener/Fuse shunt installed.

Toyota PRIUS is Subsidizing GAS GUZZLERS ?!?

Posted in PHEV on July 17, 2008 by wizbandit

So you THINK you want to do the right thing for the enviroment.  So you THINK buying a Toyota PRIUS is good for everyone.  Think again. PRIUS “scalping” is in full swing!  Yes, there is a waiting list to be scalped, like sheep to the razor, future PRIUS owners are getting in line for a wallet buzz.

I having been trying to buy another PRIUS Package #2 for months now but I’m not going to be shaved.  The PRIUS is being marked up by thousands of dollars to offset the cost of the slow selling Toyota “Gas-Guzzler” line of vehicles such as the Toyota TUNDRA coming in at a whopping 15MPG city!  My last attempt with a Southwest Florida dealership ended in dismay with a hard-set $1495 over MSRP.  In the local area I was quoted $2995 over MSRP and I was told this morning SOME Florida Toyota dealerships are charging FIVE THOUSAND DOLLARS over MSRP!

I offered a dealer to put a big “This Vehicle provide by XYZ Toyota” on the car right near “This Plug-in Hybrid Gets 100+ MPG” but they refused, any Toyota Dealers reading this willing to sell me a PRIUS at MSRP?

With demand rising and supplies falling, Toyota has – surprise! – cut incentives and raised prices. The Prius goes for an average of $25,274, up $869 from a year ago, according to JD Power.


There is NOW WAY you can recover the demand pricing on a PRIUS even if you drive 200 miles a day to work.  You have the LOAN, if you don’t pay cash, the FULL COVERAGE INSURANCE, the INTEREST on the LOAN and remember, YOU NEED TO BUY FOOD!

Don’t even get me started on your Electric Bill, Water Bill, Garbage Pickup and Telephone service on top of a NEW PRIUS to pay for. Oh, don’t forget PROPERTY TAXES!  I will continue this RANT later…

Spirit of DC PHEV visit to Tarpon Springs, Florida!

Posted in PHEV on July 8, 2008 by wizbandit

The “Spirit of DC” was here and she brought one Jerry “EVJerr” Asher by for a quick CAN-View repair and fill-up with Electric Juice provided by abundant Florida Sunshine. She had a dead, blank stare, Miss Spirit’s CAN-View V3plus was asleep.  My first diagnoses was correct, somehow the Microprocessors FLASH memory had been corrupted. Having the proper tools here in Tarpon Springs to “re-flash” the MPU’s I told Jerry no problem, well, I thought none.  I downloaded the new firmware codes from the CAN-View site and re-programmed all the MPU’s but she didn’t come back alive.  A quick email to Norm D’, the designer of the famous CAN-View PHEV computer system received a quick response and the means to get the system back working.  If Norm had not been generous with sharing information on the internal workings of his CAN-View project with me last year EVJerr might have well ended his quest only after a brief tour!



Jim Parish (Me) in the white Tee and EVJerry in the blue.

Visit to keep track of EVJerr and his journey across America (and now Canada to visit and personally thank Norm!)

I had contacted BayNews9 the evening before about a great news story on “Florida’s Energy Future” utilizing Plug-in Hybrid Electric Vehicles and Solar Power.  When I called this morning to ask if they were going to come out I was told  no.  Apparently “Powering Florida’s Future with Electric Cars & Solar Power is not Newsworthy”. Tell them how YOU feel, they thrive on viewer feedback.

PHEV Battery Failures…

Posted in PHEV on June 9, 2008 by wizbandit

I had four of the PHEV 18Ah batteries fail last week.  The first swelled up around one cell so I knew it was bad.  Strange thing is it happened during discharge and not during charging.  I got it replaced under warranty with a new one. I was doing my Saturday individual battery voltage check the following Saturday and I found one battery only charged up to 11 volts so I took it back and got it replaced. Two days later I found two more only at 11 volts.  Seems I was suffering from the classic 20 battery in series charging problem, some batteries were not fully recharging overnight.  I put one on a nice slow regulated charger and it did recover to a full 13.8 volts in two days.  The other did not so I did the only thing I could think of, slapped a 60 watt 12 volt bulb on it and left it to die overnight.  The next morning it was stone dead, I put it on a nice slow 1.5 amp charge and left it on a timer for 6 hours.  It is now back to 13.8 volts as well.  Seems it takes a lot of current to get the reversed cell to come back and the only way to do it is to discharge the other 5 cells to zero volts.  I know this is not recommended but faced with a 11 volt battery I really had nothing to loose.

Now to fix the problem.  I came up with a setup that I am glad to report is working very well.  With the suggestion coming from the eaa-phev list I rounded up some zener diodes.  I used a small 3A blade fuse holder, a 6.2V 5watt zener, a 8.2V 5watt in series across each of the 20 batteries.  I mounted the fuse holder with hot-melt glue between the batteries.  The fuse can be easily accessed from the top where you can actually put an amp meter across the fuse socket and measure the bypass current across the battery, way cool. The 3 amp fuse acts like a .3 ohm resistor.

I have put together a kit of all parts and offer it for sale for just $2 per kit is anyone is interested. (Well below the retail cost of these parts) If you want pre-cut orange and brown #16 TFFN wire the kit is just $2.25 for the wire included.  The zeners fit nicely inside the crimp sleeves, no soldering required. One kit required for each battery.

The kit contains:  one 6.2volt 5 watt Zener Diode, one 8.2volt 5 watt Zener Diode, one 3amp blade fuse, one enclosed fuse holder, two female crimp connectors, two crimp ring terminals, two crimp butt splices. (two pre-cut wires).

I will be adding assembly instructions here soon.  I will assemble if you don’t want the hassle for an additional $1 per kit.

10JUN2008 report.  All 20 batteries fully recharged overnight, the Zener Diodes equalized the pack nicely.  I know a BMS system is the ultimate answer but until I get my design finished I highly suggest the interim Zener Diode Shunt system for anyone using Lead-Acid Packs.


 (to be continued…)


Advanced Automotive Battery and Ultracapacitor Conference

Posted in PHEV on May 16, 2008 by wizbandit

I found out that Ron Gremban was at the AABC in Tampa, FL this week.  Ron, Technology Development Lead for PRIUS+, was moderator of the PRIUS+ Plug-In Hybrid Conversion Group, and co-founded the Electric Auto Association Plug-In Hybrid project. He led the team that converted the first Prius to plug in, and drives that car daily. An electrical and software engineer involved in sales of solar energy systems, he has long experience with electric cars—he helped design and drive the Caltech entry in the transcontinental 1968 Great Electric Car Race. ( Read more about Ron and his group at )

I drove over to the conference late this afternoon to offer Ron a PHEV ride to the Airport, he gladly accepted.  After the conference and on the ride to Tampa International Airport we chatted briefly about Solar Power, PHEV Battery Charging.

I felt honored to meet and talk with one of the guys directly responsible for my Prius PHEV conversion.