I would like to install an extra bettery in the sidecar, tap into the motorcycle's charging system to keep it charged, use it to power an extra GPS unit and possibly heated jacket liner for the passenger.
How do I go about wiring this extra battery?
Should I splice the wiring off the regulator/rectifier and add another lead to connect to the extra battery?
To eliminate charging problems use the (large) battery instead of the motorcycle battery. Don't keep them both in the circuit.
Lonnie
Yes, I do plan on using a car battery as the extra battery in the sidecar, but how to keep it charged with motorcycle charging system?
You can run a car battery for a long time with a bum altenator.
I use a battery tender with my rigs. Whenever it's not on the road it's on the tender. Makes bike batterys last longer too since the never get discharged they won't sulfate up so they won't take a charge.
Lonnie
Maybe you're right, I've never checked how long it might take to drain a car battery fully by connecting my GPS and heated clothes to it without charging. GPS draw about 5w, heated jacket liner 75w.. how long would you guess to drain a 40 ampH car battery?
Hard to guesstimate if you are using neither the bikes charging system or a battery tender.
Lonnie
I wired a truck battery (900cca) in parallel with the bike wiring and a quick plug to disconnect with the side car,..works great for the DVD player and laptop and very very cold morning starts,...the reserve of the truck battery gets charged with the excess from the bike system without taxing the stator, great for the high-powered lighting also,...cheers crawf.
There's no reason not to keep it in the bikes charging system, if both batteries are fully charged the charging system is only going to be replacing the lost voltage, if there is any, the same as it would be doing if you just had the bike battery hooked up, all your doing is adding more CCA, run a #10 wire to the sidecar battery from the bike battery and find a good ground on the car and your good to go, I run my heated jacket and gloves with no problems on my Shadow 1100 rig which isn't noted for having a barn burner charging system. If you want to charge when riding but not have it on line when stopped put a 30 amp relay in-line and wire it so it hot when running and off when it's not, doing that will give you a back up battery if the bike batt goes south or what ever direction they go when they go bad.
You can have issues if you try and charge a large and small battery at the same time. There should be a disconnect between the two batteries to allow one or the other to be charged by the bike.
Is this worth the trouble? In my opinion, NOT AT ALL. We feel it is best just to convert to the car battery and get rid of th ebike battery all together. We have done these conversions many times and you end up with a battery that will practically last forever, can be quick charged if desired, costs less that a puny cycle battery, can provide ballast if wanted and has enough additional capacity to run some camp lights or whatever. Not a bad idea to plug a battery tender to it when not in use but not really essential.
The exception may be If the bike will be unhooked and ridden solo then keeping the cycle battery in place and using a tender on it may be desired. When converting to solo operation simple re hook up the sysle battery.
To hook up the car battery unhook the cycle battery and just run the new leads to the present battery cables, bolt the new and old leads together and wrap things up in some fashion. Using cables that have eyes on each end and battery terminals that have a wingnut connection (marine stuff) make things simple and provides a nice way to add additional wires to the battery if desired.
You can use one of those inexpensive plastic battery boxes if desired. We typically make our boxes from aluminum and usually do them oversize. The additional space inside allows a nice place to store electrical type 'stuff' and also allows room to add various plug ins etc right on the battery box itself.
Some have added electrical recepticles for camping lights. You can take any trouble light, lamp ot whatever and switch the bulb out for a 12 volt bulb and you're good to go. If you don't want to add a recepticle then simple alligator clips work just fine.
If the battery is mounted inside the sidecar it should be vented well. We usually mount them between the sidecar and bike. See attached photos.
Thanks for the good info and pics. I think it's going to be a good project for this winter to remove the moto battery altogether and just have a car battery (or two) for the sidecar. Any wiring suggestions for the starter of the moto? haevy guage car wiring would sufice?
If the battery is mounted inside the sidecar it should be vented well. We usually mount them between the sidecar and bike
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With the sealed AGM batteries it's not necessary to do that, there's a number of smaller AGM batteries with a lot of CCA that can be mounted in the car, unless of course you just want the weight of a large battery, with my tool kit and sidecar scissor jack I don't.
After re-reading what I wrote I assumed everyone kept there rig on a battery tender and a mis-stament, The 30 amp relay is off when running and is on when off allowing the tender to charge and maintain voltage levels.
Assc's are wired to the sidecar batt, if it did get low I can jump wire the relay and charge the sidecar battery but i've never had to do that.
I have thought of going to a larger battery on my Harley but I really don't think I will. It's probably more trouble thatn it's worth after all.
I bought my bike in May, 2004 and it's still on the original battery at 5-1/2 years. It's a Harley-Davidson AGM type and I keep it on a Deltron Battery Tender Jr. all of the time. It's always ready to go. The Harley battery are terrific but they aren't inexpensive.
Interestingly, Harley changed their charging system in 2004 so that it charges at 14.5 VDC all of the time, even at idle. With the AGM battery, the system is good to go all of the time.
If you were only to use a spare battery for things like accessory lights and radio, etc, it would run for a long time between charges. I would certainly look for an AGM battery to avoid the issue of battery acid.
Hello from Manitoba. In 2007 I put a car battery in the trunk of my Watsonian Palma, now a Monaco sidecar. It adds ballast to the sidecar. the bike is a 2007 Sportster 883. subframe built by Claude. The Harley charges the battery directly from the charging system without the Harley battery inline. I used regular battery cables from the bikes cables bolted together and into the trunk, works good. Real good cold cranking with the high cranking amps. All my other connections for accessories are hooked into the bikes battery cables. I have run the car/truck batteries since 1968 on my old Triumphs and all in the trunk of the chair. Lucas electrics were never good like the new stuff. Never had a problem so far and done a lot of miles over the years. If you trip a lot, you can always hook the tender in permanently and charge over night where you stay.. Doug in Manitoba
by tying my auto batt to the charging system,..in line with the bike batt, I never have to look at either,..bike batt is there for solo, auto batt for the extra when needed,..charging system is not taxed,..no tender is needed and I'm still running the factory bike batt it came with in 2002,...seems pretty easy to me,..hehe crawf.
Do you have a simple diagram how you connected your moto battery and extra car battery to teh moto's charging system?
crawf - 11/22/2009 5:50 AM
by tying my auto batt to the charging system,..in line with the bike batt, I never have to look at either,..bike batt is there for solo, auto batt for the extra when needed,..charging system is not taxed,..no tender is needed and I'm still running the factory bike batt it came with in 2002,...seems pretty easy to me,..hehe crawf.
