Going "Commando" - No Alternator, No problem!

The Decision
After over 48,000km of listening to shrieking alternator couplings and replacing more of them than I care to remember, I was at my wit's end and desperate for a solution to the problem. For reasons that have yet to be determined, my '05 Tourist hates alternator couplings and it seems that nothing short of a major redesign of this component is going to change its mind. My own opinion is that the location of the alternator is part of the problem; tucked in behind the timing gear tower it is kept out of the cooling airflow at highway speeds and very susceptible to heat from the motor. This heat eventually causes the grease in the two coupling bearings to liquefy and flow out through the shields, causing them to seize up. This problem is not helped in my case with my insistence on running the large metal leg shields, which further reduce the chances of cooling airflow from reaching the alternator assembly. But the tradeoff here is that the leg shields actually deflect more air onto the cylinder heads, helping keep them cooler in hot weather. So I stoically put up with increasingly loud, shrill bearings and frequent coupling change outs until finally finding a solution in the form of a conversion to a total loss electrical system.

I had first heard about this concept on the IMZ Web Board and on the Russian Iron forum a while back, so I did a search on those sites to find out all I could about the process. It seemed that this conversion was done on a lot of pre-'04 Urals because of the poor reliability of the Russian made alternator, but there were a couple of late model owners that had also done the surgery. However, detailed information such as battery ratings, wiring procedures and such were scarce so I had to do a lot of research on my own to come up with a plan. I also took a look at my riding habits and realized that the majority of my runs were within the 3hr range, with the occasional longer trip to a rally or other event. As it would be impractical to carry a battery charger with me on the longer trips, I decided to make the conversion so that the alternator could be plugged back in if required. That way I'd have all the bases covered, including the possibility of an improved coupling design should that Holy Grail ever appear.

The Research
On normal bikes, the electrical supply system consists of a battery that stores and provides all the required power, as well as an alternator to keep it topped up and step in as required when demand exceeds the battery's supply. A "total loss" system, however, is one that runs on battery power alone and requires the use of an external battery charger to replenish the battery when it is not in use. Because an alternator can supply extra power when needed, the physical size of the Ural's OEM battery can be kept relatively small. But a small battery means a short supply of electrical power if the alternator were to cease output, so simply removing the alternator isn't enough to effect a change to a total loss system - a larger battery must be installed to ensure longer operation in between charging cycles.

There are two types of larger batteries, but really only one of them is suitable for total loss system use. A car battery is obviously larger than the Ural's OEM battery and can provide power for several hours before the voltage falls below useable limits, but the problem is it is designed for use with an alternator that constantly keeps it topped up. Constant discharge/charge cycles in a total loss application will greatly reduce the life of the battery because it is not designed for this type of abuse. But the other type of battery is - a "deep cycle" battery is designed specifically for applications that rely on battery power alone, like an electric trolling motor for a fishing boat or the DC power system in an RV motor home. These batteries are built to handle repeated total discharge/charge cycles, aka "deep cycles", so that is why I decided to use one for my total loss system.

Before I did that, I had to figure out what size and rating of a battery I'd need for my situation and that meant figuring out how much power draw the Ural would require in normal and a "worst case" scenarios, then matching that to a suitable battery. I did this by figuring out the current draw of all the components for both cases...

Realistically, though, the time frame would be longer because I would not be sitting for two hours with the brake lights, the signal lights on and the headlight on high beam, so the current draw would be less than 20A. Also, I could shut off the headlight and electric vest if I noticed the power beginning to fade, giving a bit more time to get home. Under normal operating conditions I estimated around 5-6 hours of useable battery power before having to shut off the headlight and electric vest and probably 6-8 hours before the ignition would cease to operate. The Ural's ignition system will function down to around 7 Volts, by the way.

So... given that the majority of my rides are within the 3 hour range, a battery with a 120 Reserve Capacity Minutes rating would do just fine for my requirements. The only unknown was the electric starter - I have yet to determine its exact cranking amperage and even if I do it will be hard to determine just how much it will deplete the battery when used. So I resolved to use the kick start as much as possible and keep an eye on the battery condition with the use of a digital voltmeter and eventually learn the time/power limits through experience.

Once I had the desired rating in mind, finding the actual battery was easy. NAPA Auto Parts coughed up this beauty for $155. It is a maintenance free sealed Deep Cycle Marine unit rated at 120 Reserve Minutes that weighs in at 37lb.

Canadian Tire had a plastic marine battery box that was a little bigger than the battery itself for $16. NAPA and CT provided the rest of the electrical parts (battery cables, toggle switches, fusebox, etc) while the local Home Hardware had the angle iron and fasteners needed to build the battery box platform.

Mounting it in the trunk of the sidecar requires the battery cables to run out through a hole over to the bike. The downsides to this are that because the rear of the sidecar flexes on rubber encased springs, the battery cables would be subjected to a lot of movement. This means that special care needed to be taken when routing them through the sidecar body as well as the requirement for frequent checks to ensure the connections are tight at both ends. Also, there is a huge loss of space inside the trunk area with this setup, along with the requirement to reinforce the floor in order to handle the 37lb battery. The up side to having the battery mounted in the sidecar is that the battery is protected from the elements.

Mounting the battery on the sidecar frame means that foot room for the rear passenger is eliminated. The battery is also more susceptible to the elements and requires a more robust mounting system to prevent it from falling off. The upsides are the heavy battery is placed lower on the center of gravity, there is no loss of space in the sidecar trunk, the battery cables are much shorter and they will not be subjected to flexing once installed. Based on my reluctance to lose luggage space and the fact that I removed the rear passenger seat a long time ago, I chose to mount the battery on the sidecar frame.

The Wiring Conversion
First step was to remove the OEM battery. Others who have done the total loss conversion have kept it in place and isolated it from the new battery by means of a switch, so that if the main battery is depleted the OEM can be used as a backup. However, this creates additional headaches with regards to wiring and in my opinion a "backup" battery isn't much use if it is only 1/4 the capacity of the main one. Proper trip planning would prevent me from being stranded with a dead battery. But I left the battery mounting plate in place anyway, just in case some day I decide to switch back to a normal alternator system.

The alternator was next. The two wires on the top terminal were removed, then fastened together with a small bolt, taped up with red electrical tape for easy identification and stashed into a secure spot underneath the gas tank. These wires must be kept together or power will not be delivered to the rest of the bike's electrical system.

The small red wire with a spade terminal that plugs into the rear of the alternator is what turns the fault light on or off on the dash. The light is lit when the motor is off, then extinguished once it is started and the alternator is turning. With the alternator removed this meant that the dash light would always be lit, as it would not receive the signal to extinguish. So the red wire was also taped with red electrical tape and stashed under the gas tank, while the bulb for the dash light was simply removed. No bulb, no problem.

The small green wire with the spade terminal at the rear of the alternator is the one that controls the relays for the electric start. With the ignition on, but the motor not running, this wire provides a path to ground that allows the starter relays to be energized. When the starter button is pressed, the power is delivered to the starter and once the motor starts and the alternator is turning, the ground is disconnected internally. This cuts the power to the relays, which means the starter will not engage if you accidentally thumb the button while the motor is running. As I was reluctant to lose the convenience of the electric start feature, I figured out a way to retain its function without the alternator. All I had to do was run a wire from ground to a toggle switch and then attach the green wire to the other terminal of the switch. With the ignition on, the toggle switch is flicked to allow a path to ground. Then the start button is pressed and once the motor is running, the toggle switch is flicked off and the path to ground is removed so that the starter relays cannot remain energized.

As I knew the rough location of where the battery box was to be mounted, I measured the distance from there to the starter solenoid terminal and the right side airbox mounting stud. The positive cable would be attached to the solenoid, as it is the same electrical location as the positive cable on the OEM battery and the negative cable with its larger terminal needed a larger mounting point. NAPA had several cables available in different lengths, so I chose two that were closest to the measurements I needed. Unlike '06 and up models, my '05 does not have a power outlet and fusebox in the sidecar. I have a sidecar mounted spotlight and a 12V power outlet that I installed, so I mounted a covered fusebox on a home made metal mounting tab underneath the driver's seat in the OEM battery area and attached the starter relays to it.

Mounting The Battery

I don't have access to a welder, so I made a frame from angle iron that was slightly larger than the base of the battery, bolting it all together. A muffler clamp secures one front corner to the sidecar frame tube and the passenger foot peg was removed and the mount rotated to secure the other front corner. One rear corner had nothing in its vicinity to bolt up to, so a standoff was made near it by using a small bolt that rests on the frame cross member and allows the frame to remain level. The other rear corner was attached to the bike via a length of angle iron bolted to the rear grab rail. With three solid mount points and the standoff, it was very secure and able to support the heavy battery.

A piece of 1/2' plywood was cut to fit the bottom of the tray, with a cutout for the muffler clamp bolt. This ensured the battery box had a solid surface to sit on, as well as keeping it from contacting any of the frame hardware. The angle iron was tall enough to allow for a lip edge to help retain the battery box in position.

The battery box was screwed onto the wood base. With the lid in place, it slotted neatly into its spot like it had been designed that way. There was sufficient clearance from the shock tower, gas can and sidecar body so that nothing would disturb it.

Once all the sharp edges were cleaned up, everything was painted and the securing straps for the lid placed in position. The cross strap passes underneath the tray, while the long strap passes underneath the frame cross member to help secure the entire unit to the frame.

The finished assembly looked good and was very securely mounted. In this photo you can clearly see why there is no foot room for a passenger on the bike.

Cables and Wiring

The vented battery box has openings to allow the cables to exit at almost any location. The lid overhangs the top of the box by about 1.5", so there is protection against water, mud and snow from splashing into the box. The battery cables were routed into the bike and secured together with zip ties.

As mentioned previously, the negative cable is fastened to the airbox mount stud and the positive cable to the starter solenoid terminal. The other positive circuit wires were attached in their original location on the solenoid terminal, too, including a power wire that goes to the new fusebox.

The new fusebox was mounted under the seat, with the starter relays secured to the back of the mounting plate. All the accessory wiring was attached, with each spade terminal getting a coat of dielectric grease to help prevent corrosion.

An alternator hole cover plate was made from a piece of heat resistant plastic I had lying around and an old inner tube was cut to make a gasket for it. Angle iron was used to provide a mounting point for the Gummi's Airbox on the right and the Fiamm horn on the left. This setup allows for the alternator to be plugged back in at any time without having to rework any of these mounting points.

A headlight cutout switch was mounted on the side of the dash. The ground wire at the headlight bucket is where it hooks up to.  If the battery voltage drops too low, the headlight is switched off to conserve power. Another toggle switch was installed on the other side of the dash to power the sidecar-mounted spotlight.

The toggle switch for the electric start was mounted in an existing hole on the seat plate. If the Ural ever stalls in traffic, it is within easy reach to activate and the bike can be fired up a lot quicker than by dismounting to use the kickstarter.

The "Commando" Electrical Conversion in all its glory. It looks a little freaky with all the open space under the gas tank, but you really don't notice it unless you're crawling along the ground on hands and knees... and if you are, you're probably too drunk to notice this, anyway.

The Results
Initial tests of the new system went very well and it wasn't long before I had logged over 400km, trouble free. A pigtail connector was added as an afterthought, exiting the rear of the battery box, to allow a battery charger to be hooked up without having to remove the lid as well as providing an alternate power point for such luxuries as a small 12V cooler or a heated vest for the sidecar passenger. I estimate the useable range of the system under normal conditions to last about 5-6hrs between charges, but so far have only made trips of less than 2hrs duration due to winter weather setting in. Eventually I plan to install LED bulbs for all the signal lights to further reduce the power consumption. Total cost for the conversion including paint, hardware, angle iron and the various electrical bits, rings in at around the $250CDN mark. But when compared to the cost of rebuilding an alternator coupling every few months and the blessed peace and quiet that comes from puttering along without a screeching alternator, really, the value is priceless.

Mike “Gummiente” Palmer

Canadian Ural/Dnepr Riders Group (CURD)