I have a battery in my sidecar that only runs the electrics in the sidecar which needs to be hooked up and charged with a battery charger. Is there a way to hook up to the MC system so I can charge while riding and then switch back to the MC system battery?
I use an auto battery in the trunk to power the tub's auxiliary items... it's just easier to put it on a tender once in awhile. Doesn't need constant charging due to the large capacity of the battery and relatively small draw placed on it.
If you're going to charge it off the tug's alternator, why not just eliminate that (smaller) battery all together?
If you do not want to hastle a lot. simply put a pull / throw switch between the 2 battery plus lines and on the common the line that goes into the bikes battery. While you drive flip from one batery to the other and things work. (just put the s/c battery negative on ground) The charger will handle the s/c 's auto battery easily because they work on the same voltage. Many take even out the bike's battery.
Sven
As I recreate my rig, I plan on using a flat 4 wire trailer connector between the car stop, turn, tail lights and the bike for simplicities sake should I have to remove the car. Max
Common practice, Max.
So is using a cheap auto battery in the boot and eliminating the expensive bike battery. Just be sure to secure the battery well and have it in a spill proof box. As a bonus you also get extra ballast.
Lonnie
Boating stores have switches that let you charge Battery 1, Battery 2 or Batteries 1 and 2.
Rich
Important: don't use both batteries in parallel, without a proper system separation they will damage each another!
Sven
I tird a car battery in my trunk for a while, but the floor stated rusting badly. What's the cure for that? Better ventilation?
Use a marine battery box and ventilation.
Lonnie
Also consider using a Sealed Marine or RV Deep Cycle type battery that is designed for Total Loss systems and can handle the Deep Discharge/Re-Charge cycles that normal Auto and MC batteries can't.
Depending on the size of Battery you use in the Hack and the charging system on the bike it may be possable to build a circuit from the bikes Alternator using a Diode that will prevent it from feeding back to the bike so that it only feeds the accessories on the side but accepts a Charge from the bike.
If you want to get really involved a PWM, Pulse Width Modulator, can be used to replace the Diode circuit and limit the current drain from the Bike that is charging the Sidecar Battery. It can be adjusted to a low current flow level that will keep you from dumping the entire output from the bikes Alternator and Battery into the Sidecar Battery all at once.
A switch can be added to turn off the Sidecar Charge Circuit as well.
PWM's are commonly used for Heated Clothing awa Heated Grips and could be modified to use in the above Controlled Charge Circuit.
What a PWM does is simply turn on and off the power flow of 12VDC at an adjustable rate to limit the amount of Time, or Pulse Width, that the power is turned on. A narrow Pulse Width will provide full voltage spikes for short periods of time thus limiting the current flow from the bike to the Sidecar Battery allowing a low level charge without loading the bikes alternator any more than you allow by the adjustment you set with a Pot or Switch on the PWM.
My choice of a Bike to Sidecar Battery Charge Circuit would be with a PWM and the same thing could be done to charge a battery in a Camper Trailer.
If you go this route connect the PWM to an accessory circuit that is fed from a relay that is OFF when the bike isn't running and has enough current, wire size & fuse etc, capacity to charge the sidecar at the rate you set with the PWM control.
Thanks for the info. I will go to a marine store and go that route with a switch.
Welcome Max. It sounds like you have a good plan. Battery also makes good ballast.
Phelonius Yep, here too.
I'll just chime in here because no one else mentioned this. If you are going the 2 battery, manual switch route, be sure to alternately charge the batteries on a regular basis so that neither battery gets very low. You don't want to pop a regulator or stator trying to bring a very low, very large battery up to charge with your bike alternator.
Automotive and marine alternators typically have a 20% duty cycle. This means that if they are required to operate at full output they can only do so for 20 minutes each hundred minutes. They then must rest for 80 minutes to dissipate the heat that has built up in the stator windings and regulator heat sinks during the 20 minutes they were operating at peak(20+80=100). Most automotive alternators are physically larger than what is incorporated in most motorcycles. Most of the reason is because the batteries in cars are larger.
Motorcycle manufacturers do not publish their duty cycles. I would guess from experience, that it is what is necessary to keep the size of battery that the system was originally engineered around in a good state of charge under expected operating conditions.
A larger than OEM battery, such as a car battery, that is allowed to get discharged could easily exceed the duty rating of the electrical system of most motorcycles. Normally when that happens there is a lot of smoke and arcing followed by a string of words that can not be posted here.
So rather than take the chance. If you believe the car battery has gotten low in the hack just plug it in with a inexpensive charger when you get near a ac power source. If it is only slightly discharged use the bikes system to charge it.
Joe
"In each lifetime there are only allotted so many motorcycle rides. Ride while you can."
Originally written by Uncle Ernie on 8/2/2008 4:25 PM
I tird a car battery in my trunk for a while, but the floor stated rusting badly. What's the cure for that? Better ventilation?
AGM (Absorbent Glass Mat) batteries are much better at avoiding corrosion. They don't put out liquid acid through a drain tube. They are much more expensive, however.
Originally written by fastjoe on 8/4/2008 1:46 AM
I'll just chime in here because no one else mentioned this. If you are going the 2 battery, manual switch route, be sure to alternately charge the batteries on a regular basis so that neither battery gets very low. You don't want to pop a regulator or stator trying to bring a very low, very large battery up to charge with your bike alternator.
Automotive and marine alternators typically have a 20% duty cycle. This means that if they are required to operate at full output they can only do so for 20 minutes each hundred minutes. They then must rest for 80 minutes to dissipate the heat that has built up in the stator windings and regulator heat sinks during the 20 minutes they were operating at peak(20+80=100). Most automotive alternators are physically larger than what is incorporated in most motorcycles. Most of the reason is because the batteries in cars are larger.
Motorcycle manufacturers do not publish their duty cycles. I would guess from experience, that it is what is necessary to keep the size of battery that the system was originally engineered around in a good state of charge under expected operating conditions.
A larger than OEM battery, such as a car battery, that is allowed to get discharged could easily exceed the duty rating of the electrical system of most motorcycles. Normally when that happens there is a lot of smoke and arcing followed by a string of words that can not be posted here.
So rather than take the chance. If you believe the car battery has gotten low in the hack just plug it in with a inexpensive charger when you get near a ac power source. If it is only slightly discharged use the bikes system to charge it.Joe
"In each lifetime there are only allotted so many motorcycle rides. Ride while you can."
Those are good points. I'm considering using a car-sized AGM batery in the trunk of my HD sidecar. I would remove the bike battery altogether and just charge the car battery with the bike. I always leave my bike on a battery tender when parked so that should take care of the need to charge a low car battery with the bike alternator.
