|Owner||Douglas De Boer|
|Location||Dordt College, Sioux Center, Iowa US map|
|Vehicle||1998 Plymouth Neon Highline |
Converted to battery-electric power by senior engineering students at Dordt College during the spring of 2009.
|Motor||Advanced DC FB1-4001A Series Wound DC|
|Drivetrain||Front wheel drive|
Five-speed manual transmission
Clutch was retained in the conversion
|Batteries||12 Trojan J-150, 12.60 Volt, Lead-Acid, Flooded|
Energy capacity of the battery pack at a 75 A discharge rate is calculated from manufacturers specifications as about 12 kWH (45 MJ for those who like SI units). Actual experience shows this is about right, 12 kWH can be drawn from the battery pack while maintaining acceptable performance.
Four batteries under the hood
Five batteries under the back seat
Three batteries in the trunk
There is one more battery mounted under the hood in front of the left front wheel. This is the original battery formerly used to start the gasoline engine and now used to power the 12 volt systems of the car such as headlights, windshield wipers, radio, etc. and also the 12 volt contactors and relays needed to control the 144 volt system.
|System Voltage||144 Volts|
|Charger||Quick Charge On Board Select-A-Charge model SCO14410|
120 VAC(RMS) 60 Hz input
Nominal 144 VDC at 10 A output
The charger is permanently mounted in the trunk. This allows me to re-charge wherever I can find a standard 120 V electrical outlet.
See "Additional Features" below for more detail about this charger.
|Heater||No heat so far, but the blower works.|
|DC/DC Converter||Elcon |
ElCon 144VDC input/13.5 VDC output, 37 Watts WebPage (purchased from EV America WebPage )
|Instrumentation||Westburg voltmeter, 80-180 V (traction battery voltage)|
Westburg ammeter, 0-400 A (traction motor current)
Stock speedometer and odometer
Kill-a-Watt Energy meter on the charger
|Top Speed||60 MPH (96 KPH)|
Designed for 60 MPH tops. Have driven it up to 55 MPH and it easily has more to give.
|Acceleration||Moderate. Can keep up with traffic easily but will win no races against a gasoline powered car.|
|Range||30 Miles (48 Kilometers)|
About 30 miles (50 km) CITY
About 20 miles (30 km) HIGHWAY
See "Additional Features" below for more information about driving range.
|Watt Hours/Mile||550 Wh/Mile |
Measured from the wall plug to the road. Data taken to date is a bit sparse, better data will be available later. I use a "Kill-a-Watt" meter WebPage to measure the power needed to recharge. I divide that by the miles driven since the previous charge. I'm using an aggressive charge profile to assure that the weakest cells reach full charge. That may account for the somewhat high power consumption I'm experiencing to date. I estimate that the energy delivered to the motor is about 300 Whr/Mile but I have no reliable data yet.
|Seating Capacity||2 adults (front bucket seats) and 3 children (in the rear bench seat). Batteries located under the back seat raise the seat a few inches reducing headroom and making the rear seat impractical for adults. The car has the stock seat belts. (That's lap & shoulder for each front seat and each out-board rear seat and a lap belt only in the center-rear.)|
Load/Speed Rating: 86H
Type: All-season "performance" radial
All four wheels the same.
|Conversion Time||The conversion of this car was a student project at Dordt College, Sioux Center IA, WebPage as an engineering WebPage senior project. There were six students on the project. On average, each put in about 80 hours on the project giving a total of 480 hours of student work in the project. This includes selection of a donor vehicle, preliminary simulation, researching vendors, some travel time to purchase various items, and the actual conversion work.|
|Conversion Cost||Donor vehicle: $1500 (US Dollars)|
Total: $11500 (about, as of July 11, 2009)
Estimated cost of electricity for a full charge: $0.75.
Driving past gas stations: "priceless"
|Additional Features||CHARGER DETAILS*******************|
Quickcharge On Board Select-A-Charge Model SCO14410
120 VAC(RMS) 60 Hz input
Nominal 144 VDC at 10 amps output
The charger is permanently mounted in the trunk. This allows me to re-charge wherever I can find a standard 120 V electrical outlet.
This charger is set up with a "3-stage charge profile."
1) Bulk charge at a constant 10 A until voltage reaches 174 V. During this phase of charging the voltage of the battery pack slowly rises from whatever it was at the beginning of the charge to 174 V. When it reaches 174 V that causes the charger to switch to phase two. The initial battery pack voltage could be low as about 130 V but typically it is about 140 V to 155 V.
2) Gas (equalize) at a constant 174 V for 3 hours. During this phase of charging the DC current to the batteries declines from 10 A down to about 1 A.
3) Float at a constant 163 V until unplugged. During this phase of charging the DC charging current to the batteries is typically less than 1/2 A.
In my experience, this charger is a good value for the money, but also marginally adequate for my needs. I'm satisfied and have no plans to upgrade the charger, but others might value a charger that works faster.
The charger has a power factor of about 0.75, which is a bit low. This means you will want to plug it into a 20 A circuit and to have good heavy wiring from your household AC service panel to the outlet, and a heavy and short extension cord to the charger on the car. The charger wants to draw about 15 amps or a little more during the early hours of the charge cycle. Even with this setup, it can take more than 12 hours to achieve a full charge after driving more than 20 miles. If you put this charger at the end of a cheap 100 foot extension cord (cheap = 16 gauge, 100 feet = 30 m) you can expect a full charge to take more than 20 hours. I've tried it!
If I were going to extend the range of this car by improving the batteries, then I would definitely change to a 240 V charger. Even if I routinely planned to drive about 15 or 20 miles every single day, I'd upgrade to a 240 V charger to make charging faster and more convenient. I'm using the car on average about 4 or 5 miles per day.
DRIVING RANGE DETAILS********************
Actual driving experience shows 30 miles range in city driving with good performance (top speed of 55 MPH achievable) and less than 60% of the battery capacity used.
The car was designed for 20 miles range in city driving using about 60% of the battery pack's energy capacity. Actual performance is a little better than anticipated.
A voltmeter is used to estimate state-of-charge while driving. I occasionally use a hygrometer to make a final determination of state-of-charge before recharging and to improve my ability to estimate state-of-charge based on voltmeter readings.
Experience shows about 20 miles of highway driving on 55 MPH roads is realistic.
Simulations prior to building the car promised up to 40 miles in flat level driving at a constant 55 MPH and running the battery down to 20% state-of-charge. Reality is that the roads are not flat and level and that as the battery state-of-charge goes below about 50% (at about 20 miles range) the batteries can no longer provide enough power to maintain 55 MPH on up-hill driving. Thus, even if the batteries can provide more range, one does not enjoy driving the car this way. If you are using a simulation to predict range, you need to include the effects of hills and stopping and accelerating to full speed occasionally, as at stop signs.
*****January 17, 2009*****Conversion work starts*******
Started removal of gasoline engine and related parts.
*****May 6, 2009*****Maiden Voyage********************
Maiden voyage on electric power. Traveled about 2 miles. Some instrumentation and on-board charger were not yet installed. A loose shift cable to the transmission caused problems shifting. After this voyage the car went back into the shop to fix the transmission cable and add instrumentation.
*****May 7, 2009*****Sioux City Journal***************
On Thursday, May 7 there was a front page story in the Sioux City Journal about this project. The text of the story can be found here: WebPage The same article was picked up by the Siouxland Business Journal WebPage (link no longer works) and later in abridged form by the Doon Press.
*****May 11, 2009*****Sioux City Journal Web Update******
On Monday, May 11 the Journal posted a video update to the May 7 front-page story. WebPage .
*****June 4, 2009*****Sioux City Journal & car show*****
On Thursday, June 4 the Neon Re-Volt was again mentioned in a Sioux City Journal Article. WebPage (The "Show & Shine" car show was delayed by rain to July 11, 2009.)
*****June 4, 2009*****Parade********************
Put the car back on the road, now with instrumentation. Drove it in the city of Sioux Center's "Show and Shine" car parade on Friday, June 6. Continued driving the car around town for personal use until June 15, 2009. Put on about 32 miles.
*****June 15, 2009*****Install Charger***********
Back in the shop for installation of the on-board charger. High voltage wiring was also re-routed to a more secure location.
*****July 10, 2009*****"Show and Shine" car show*******
On the road again, with on-board charger. Will show the car on Saturday in the Sioux County Fair's "Show and Shine" event.
*****July 11, 2009*****Winner: Best Mopar**************
The "Neon Re-Volt" won the "Best Mopar" award at the 2009 Sioux Center "Show and Shine" Car Show, held at the Sioux County Fair. There were no other electric or hybrid cars at this event. The other cars were either restoration cars, generally from the 1930's to the 1970's, or souped up recent models. The "Neon Re-Volt" was recognized for the uniqueness of the changes made to this car and the amount of modification that this car had undergone.
*****July 25, 2009***** Mentioned in NW Iowa Review *****
In the July 25, 2009 edition of the Northwest Iowa Review (newspaper) this electric car is mentioned in an article about Dordt College's engineering program.
*****August 7, 2009***** 37 Mile Range Proven *******
Between August 4 and August 7 I drove the car 37 miles in city driving. At the end of this span the car was getting lazy and could not easily achieve a speed over 45 MPH any more, but could be driven in city traffic acceptably. The specific gravity of the battery electrolyte just before recharging was 1.13, indicating about a 30% state of charge according to the battery manufacturer's literature.
*****August 10, 2009*****New Transmission Oil, Tires*****
The transmission oil has been replaced with the Mopar brand factory recommended oil. (The transmission had been re-filled with generic "manual transmission oil" after the transmission was re-installed with the electric motor.) The factory specified oil is lighter weight then the generic. This might improve the driving range a little. As a small side-benefit, the transmission shifts with less effort now. The tires on the car have also been replaced with used Hankook (brand) tires. Nothing special, but the tires that were on the car were worn down to the tread wear indicators. Now there is about 1/4 inch of tread on all four tires.
*****Update: August 10, 2009*****Another Car Show*****
This car will be shown in the Rock Valley Iowa "Rally in the Valley" car show, Saturday morning, August 15, 2009. The car will also be in the parade in Rock Valley that same Saturday.
*****August 15, 2009*****3rd Place In Car Show******
On Saturday the Neon Re-Volt took third place in the "Late model modified car" category in the "Rally in the Valley" car show, held in Rock valley Iowa on this day. The car also was part of the "Rock Valley Days" parade, also held this day. Rock Valley is 15 miles from Sioux Center.
The car is usually garaged in Sioux Center. On Friday evening I drove the car from Sioux Center to the Rock Valley high school and plugged it in to re charge in their shop. On Saturday, driving to the car show, in the parade, back to the car show, and then back to Sioux Center the car put on 20 miles. Fifteen of those miles were on the highways at speeds of 55 MPH. At the end of this trip the specific gravity in the battery pack was 1.230, or about 75% state-of-charge ("3/4 Full") according to data from the battery's manufacturer. The motor draws about 150 to 200 A to maintain 55 MPH, allowing for average hills. There is a steeper hill (uphill) traveling east out of Rock Valley on US highway 18. The motor drew 250 to 300 A on this hill.
I also taped a thermocouple to the motor for these trips. The thermocouple was located at the transmission end of the motor where the motor's internal fan exhausts air. The exhaust air was about 10 to 15 degrees F warmer than ambient while driving on the highway. (The motor also has a high temperature limit switch in the brush box. I have connected that to an ohmmeter that beeps when the circuit is closed. I have never tripped that to date. Eventually I'll get this permanently connected to an idiot light on the dash board.) The motor controller is the next item I'll monitor for temperature. It seems to run a bit more than 15 degrees above ambient, but it has never been too hot to rest your hand on it indefinitely, including after these highway trips to and from Rock Valley.
This 15 mile jaunt on the highway is the longest sustained high-speed trip the car has made to date. It did well.
****August 19, 2009****Will Be In The Ireton Car Show *****
Plans have been finalized to have the car in the Ireton "Show and Shine" car show on Saturday, August 22, 2009 from 2 to 4 PM.
****August 29, 2009****Watered Batteries & Checked Connections*****
Up to this time the batteries have not been watered from the time when I purchased them. Last week I noticed a few cells with just about 1/8 inch of water over the plates prior to charging, so it was time to water the batteries for the first time.
Most of the cells took about 1 ounce of water (30 ml) although a few needed none and a few took about 2 or 3 ounces. I suspect that the batteries were not uniformly watered when they were new. Overall the entire battery pack took about 3 quarts (about 3 liters) of water.
In the process I noticed one of the connections to a battery was visibly corroding. This same battery had some acid that had wept out of one of the vent ports and left a damp residue on the top surface of the battery. This inspired me to disassemble and check all the battery connections, but I found little other corrosion. Since I had each connection apart, each got cleaned and re-assembled, but it now seems this is not necessary unless there is visible corrosion.
I cleaned the top of the battery that had the corroding connection. I cleaned it with a disposable paper towel dampened with an ammonia-based glass cleaner. I used ammonia because it will neutralize the acid and because ammonia will evaporate and leave the top of the battery clean and dry with no residue. I checked for electrical leakage before and after cleaning. I used a voltmeter for this. I connected the positive lead of the voltmeter to the positive battery terminal, then slid the negative lead of the voltmeter around on the plastic top of the battery looking for voltage. Before cleaning there was voltage present on the plastic surface due to the acidic dampness. After cleaning, no voltage.
BTW the car garnered a pleasing amount of attention last week (August 22) at the Ireton car show.
*****September 1, 2009*****Trip to Orange City**********
I drove the car from Sioux Center to Orange City and back, a round-trip distance of 20 miles, without recharging in Orange City. This is the longest highway trip done on one charge to date. The car had 5 miles of around-town driving from the time of the most recent re-charge to the start of this trip. The car did OK on this trip and could maintain highway speed although for the last few miles one could feel that the car could not accelerate rapidly, as for example what might be needed for a passing maneuver on the two-lane highway. After returning to Sioux Center I continued to drive the car around town for about 6 more miles before recharging. The car accelerated normally in city driving after the trip to Orange City. Thus the car traveled a total of 31 miles on one charge, 20 of these miles at highway speed. The specific gravity prior to re-charging was 1.190 or 55% state-of-charge.
*****September 9, 2009***** Mentioned in Akron Hometowner
This car is featured in a story about the Ireton Ag Day car show. The story is on page 13 of the September 9, 2009 edition of the Akron Hometowner (newspaper).
*****December 4, 2009*****Watered Batteries*************
I watered the batteries for the second time in the life of these batteries. The entire set of 12 batteries took about 1.3 gallons (about 5 liters) of water. The electrical connections all looked good. I made a small tool of a light bulb on a plexiglass board about 1/2 inch by 3 inches, a screw through the plexiglass to probe into a cell, and a jumper wire with an allegator clip on it. The light bulb has one terminal connected to the screw (probe) and the other connected to the jumper wire. I adjusted the screw (probe) so that the end of the screw was at the desired level of the electrolyte in a cell. I connected the jumper wire to one of the battery terminals and added water until the light turned on. I also used about 12 feet of thin tubing to siphon water from a jug placed on a shelf about
four feet above the batteries. I pinched the end of the tubing to control the flow. These techniques helped reduce the time spent filling cells to about an hour and a half. The last time I did this (August 29, 2009) it took about four hours. I checked all battery connections for tightness. Most took another quarter turn or so. (Could the lead be creeping so as to let these connections get slightly loose?) There were two or three battery connections showing a slight amount of corrosion. I decided they could be cleaned up later when the weather is better.
*****December 14, 2009*****Winter Driving*********
Almost daily now people stop me in the parking lot to ask me how the car is doing in the cold weather. For the past week (December 9 through 11 particularly) temperatures have been a bit below average. WebPage We have also had several inches of snow. I've driven the car in several inches of loose snow now. My experience is that the car drives really well in the cold and in the snow. The lower center of gravity and extra mass given by the batteries make it easier to control on slippery roads than it was as a gasoline powered car. The electric motor and controller and batteries provide plenty of power for driving through loose snow. The only real effect of the cold weather is that I do not dare discharge the battery pack fully since that might allow it to freeze. (I have no heaters on the batteries and I keep the car in an unheated garage.) I'm still also using about 550 kWH per mile. If the cold weather is causing extra energy consumption, I've not noticed it yet.
Many people also ask about defrosting the windows since the car has no heat. It turns out that this is not as much of a problem as I had expected. In most weather, just switching on the defroster fan does the job without any heat. Thus the car remains on the road and fully drivable even in sub-zero temperatures most of the time. Other than as a creature comfort, the only time I've really wished for heat has been in the late evenings when frost is forming on everything. Then I have had to scrape the windshield on the outside, only to watch it frosting up again a mile or so later.
Conclusion: In spite of the limitations of the batteries, electric cars are great performers for short winter trips. Just switch on and drive! None of that rough idling, stiffness, and hesitation that you can get from a cold ICE. There is no need to waste energy heating up a whole engine block and related parts. Once I get a heater in my car I'll definitely prefer it as more comfortable and convenient on short trips compared to a gasoline powered car.
*****February 23, 2010*****One Thousand Miles***********
On this date the odometer rolled past 130532, which marks the first 1000 miles of all-electric driving. Considering that the car has been in regular service since about August, I'm driving the car about 2000 miles per year. Essentially all of that driving is the kind of short trips that rot out mufflers and leave sludge in the oil on ICE cars since the engine hardly has time to heat up before the trip is over. Instead, this EV has been a stellar performer for theses kind of trips.
***April, 2010*** Problems from Weather & Wear ********
This month I had a few problems with the 12 volt system. First I noticed dim headlights, meaning that the DC/DC converter was no longer keeping the 12 V accessory battery (the old starting battery) charged. This turned out to be caused by a corroded fuse holder. The fuse holder was located rather low in the engine compartment near the 12 V accessory battery. Over the winter the weather got to it. Eventually the corroded connection caused the fuse to overheat and blow. This opened the 12 volt circuit from the DC/DC converter to the 12 volt battery. I cleaned up the corrosion and relocated the fuse holder to a higher location. Later I hope to replace the fuse holder with an entirely weather-tight fuse holder.
A week later a different 12 volt fuse blew out. This fuse provided 12 power to the primary contactor, thus I lost all traction power and was left stranded. Being only two blocks from home was fortunate--I could push the car home without calling for a tow. The problem turned out to be a wire that was free to flap around with the bouncing of the car. It finally shorted to the chassis. Moral of the story: Fasten all your wiring harnesses down well. We have practically all our wiring harnesses in flexible plastic conduit and held to the firewall, fenders, etc. with adhesive cable ties. Wouldn't you know that just one wire that was not so protected would be the problem. And how frustrating to realize that we left a very important wire unprotected!
Another weather-related problem is that I noticed some of the high-voltage cable hanging about an inch (25 mm) below the bottom of the car. This is the cable that brings power from the rear battery packs to the front of the car. Apparently while driving through some snow two of the cable clamps that held the cable up got ripped loose. The cable itself was completely undamaged. the insulation is not even scuffed. We had used sheet metal screws on the cable clamps that held the cable up. They were stripped right out. I replaced the sheet metal screws with nuts, bolts, and washers. This cable runs through an area where the exhaust pipe once ran. That area also corresponds to the center hump of the floor of the car. Even in that recessed area, snow put some force on the cable.
*****May 15, 2010*****Battery Maintenance***************
Removed and re-installed all the batteries under the rear seat and in the trunk for cleaning and inspection. Cleaned the tops of the batteries under the hood. Checked all battery connections for corrosion. Watered all the batteries.
About one year into the life of the car as an electric car there is some minor corrosion of the battery boxes now. It appears this is caused by electrical leakage through moisture and contamination on the outside surfaces of the batteries. I cleaned up the corrosion but did not re-paint the surfaces of the battery boxes. The largest area affected on a battery box is about three inches in diameter (76 mm) and has not noticeably thinned the metal. There are about a dozen areas about the size of a dime (18 mm diameter) or less where corrosion has removed the paint but the underlying metal is still smooth and normal-looking (gray in color) after rubbing away the corrosion that had adhered to the surface.
If I were to do this project again I would re-think the use of metal for the battery boxes. We made the battery boxes from angle iron and sheet metal. The boxes are about an inch deeper than the batteries are tall. The boxes have Plexiglas covers so that the batteries can be seen but not touched when the car is on display. It seems obvious that some steel is needed for strength, but it needs to be kept away from the tops of the batteries, where the electrical leakage currents seem to be the worst. Our metal battery boxes are completely lined inside with thermally insulating foam. We chose an acid resistant foam sheet--it is a type used to insulate foundations of buildings. We also expected that foam to provide electrical insulation. The foam is indeed an insulator, at least when it is new. But, small areas of the foam that were laying against the areas of corrosion are now slightly conductive. If you press the probes of an ohmmeter on the foam you can measure some megohms of resistance over a distance of an inch (25 mm) or so or through the foam from one side to the other. Clearly, acid from the batteries is beginning to saturate the foam. I may have to eventually replace the foam, even though it looks like new.
Of the 24 battery terminals (two on each battery) 5 had some minor corrosion. I cleaned them up with ammonia-containing window cleaner, then put a light coating of grease on the terminals and re-assembled them. The corroded terminals were near areas of corrosion on the battery boxes. Thus the corrosion seems to be enabled by electrical leakage over damp or dirty exterior surfaces of the batteries. I expect some of the dampness on the surfaces is due to water vapor formed during charging and some is due to condensation, as when the car is parked outdoors overnight and dew forms.
A few days previously I had observed about 1/8 inch (3 mm) of electrolyte over the plates in the cells after driving for 21 miles on one charge. This low level is what motivated me to water the batteries. (I also checked the specific gravity of one cell. It was 1.22 indicating about a 70% state of charge.) Since the electrolyte level rises as the battery is charged, I first charged the batteries fully. That brought the electrolyte level up to about 3/8 inch (10 mm) above the plates. The whole pack of batteries then took about 3 quarts of distilled water to raise the level in the cells to about 1/8 inch (3 mm) below the bottom plastic edge of the fill hole, which is also about 5/8 inches (16 mm) above the plates in the cell. That works out to about 1.3 fluid ounces (about 40 ml) per cell. This is about two quarts less water than I used when I last watered the batteries on December 4, 2009.
I checked the specific gravity of a few cells after a full charge cycle and before adding water. The ones I checked were all at about 1.30. All batteries (6 cells per battery) were within 0.14 volts of each other. In short, the battery pack appears to be in very good condition. A day later after watering the batteries and after some driving and another full charge cycle, the specific gravity was 1.28, probably a bit lower due to the additional water recently added to the cells. (The battery manufacturer specifies that fully charged, the specific gravity should be 1.275.)
Removing the covers from the battery boxes takes about 30 minutes (Ten minutes per cover, three covers). Re-installing them takes about the same amount of time again. Watering the batteries (all 72 cells) takes about 90 minutes. Thus watering the batteries takes about two-and-one-half hours. All the other work, cleaning battery boxes and terminals and investigating the electrical leakage through the foam insulation of the battery boxes, etc., made it a full-day project. Doing this twice or three times a year seems to be what will be needed to keep the car in good condition. I'm impressed by the value of minimizing this maintenance time. I like electrical projects, but this work is just busy work. While designing the car we did not think much about how long it would take to remove the cover of a battery box, etc. Some changes in the design could have saved maintenance time.
*******May 28, 2010*****Will Be In "Show And Shine"*****
I'll be showing the car on Saturday, June 5, 2010, from 10 AM to 2 PM (weather permitting) in the "21st Annual Show & Shine Car Show" as part of the Sioux Center Summer Celebration. WebPage The car show will be on the east side of Central park in Sioux Center, Iowa. Central Park is located on US Highway 75 between 4th and 6th Streets NE.
******August 8, 2011******Watered the Batteries********
The traction batteries took 2.7 gallons. I also topped up the accessory battery for the 12 V system. Connections were cleaned and tightened as needed.
*****Oct 27, 2011*****Status Report***************
The "Neon Re-volt" continues in regular service. Other than periodically adding water to the batteries no other maintenance work has been done since the May of 2010. The car is proving itself very reliable.
******January 3, 2012******Watered the Batteries******
The traction batteries took 1.33 gallons. The battery connections were clean--practically no corrosion.
*****June 8-9, 2012*****Car Show***************
I drove the "Neon Re-volt" in the "Sioux Center Summer Celebration Cruise Night" parade on Friday night and also displayed it in the "Sioux Center Summer Celebration Show and Shine" mid-day Saturday. The car still draws considerable attention.
******July 18, 2012*****Watered Batteries**********
The traction batteries took 2.7 gallons of water. I also topped up the accessory battery for the 12 V system, which is the former starting battery.
*****August 10-11, 2012*****Car Show***************
I drove the "Neon Re-volt" in the Rock Valley, Iowa "Rally In The Valley Cruise Night" parade on Friday night and also displayed it in the "Rally In The Valley Car Show" from Noon to 3 PM Saturday.
*****November 27, 2012***Watered Batteries***********
The traction batteries took 3.5 gallons. I did nothing with the accessory battery as it seems to require less frequent watering. There were a few connections with minor corrosion in the battery pack under the rear seat. They will probably need to be cleaned up during the next summer (when the weather is nicer for that kind of work).