Will Charging the Camper's Battery off my Spyder overload the Alternator

[IdahoMtnSpyder]

I am wanting to charge a RV battery in my Timeout Slipstream camper which I pull with my 2016 RTL. I have run positive & negative wires from the cranking battery to the rear of the bike with a fuse at the battery.

At the trailer connection I have a simple 4 pin plug for the trailer lights, with a separate 2 pin battery tender type plug for the battery charging connection. This way I can disconnect the trailer charging circuit when stopped for the night to keep from drawing power from the cranking battery in the bike.

In the trailer I have mounted a 100 AH deep cycle gel cell battery. The plan is to connect the charging wires to the battery to keep it charged when traveling. The purpose of the trailer battery is to charge small electronics, i.e. tablet, laptop, camera batteries, etc.

My question or concern is: will this overload the alternator on the Spyder? :yikes: And if so, is there a way to accomplish this? :dontknow: I have the same type of setup on my trucks with batteries on different trailers that power small winches and hose reels, and this works great for that. :yes:

Right now, I have a reading of 12.8 volts at the plug at the back of the bike when stopped. When the bike is running it jumps up to 14.5 volts, which is consistent with my truck readings. I also plan on plugging a battery charger to the trailer plug when stopped and shore power is available.

Have any of you attempted this, and if so what do I need to look out for?

T.I.A.

I did this exact thing to charge my deep cycle battery in my trailer. I used 10 AWG to connect the Spyder battery to the trailer battery. The connection, an SAE two wire connector, is separate from the regular trailer wiring and connector. Here is the isolator/controller I used.

https://www.powerstream.com/battery-isolator.htm

The main advantage of using this system is the use of solid contact solenoid to connect the trailer battery to the Spyder charging system. Some have suggested using a diode to provide isolation. The problem with that is a diode will drop the voltage crossing it by about 1.5 volts. When you're dealing with the 13+ volts needed to charge a battery 1.5 volts can be a big hurdle. The electromechanical relay has close to zero voltage drop across the contacts so you get to use the full charging capability of the Spyder system. Also, this system provides total isolation between the batteries when the bike battery is below 13 volts. You can run down the trailer battery without being concerned about running down the Spyder battery at the same time.

The attached PDF shows how the Power Stream controller is to be connected. You don't have to use their solenoid. I don't remember what I used but it's capacity was enough to handle the charging current to the trailer battery.

View attachment Battery isolator.pdf

 

[Bfromla]

Adding one of these isn't a bad idea either. Not promoting this particular brand or model. Just an example of what I mean. Can come in REAL handy. They will charge your phone and jump start your vehicle if all else fails. For the price, they can be a real help when needed. When I carry one, it always seems like someone needs it. Never had to use it on my bike. But I know it's there if needed.

View attachment 204523

they quite handy indeed,&:roflblack: simple enough I can trust my lil sister to use:roflblack:opcorn: have picked up a few to assist family members set a calendar reminder to top off charge every 90days. (Most any li-po). Keeping them ready for the if & when. Rugged geek has nice case, Bully has a decent zippered pouch, the Halo lil soft pull string pouch. Each has basic features; jump start connection, flashlight, USB ports. (Some USB-A & or Combination A & C) some have a barrel connection various output voltage. Do like Rugged Geek has a Master on/off switch & button-not as ez accidentally draining. Worth researching & finding what fits you best & maybe luck out find some on sale at events(beware old boxes too long on shelf & is a brick)

 

[EdMat]

I did this exact thing to charge my deep cycle battery in my trailer. I used 10 AWG to connect the Spyder battery to the trailer battery. The connection, an SAE two wire connector, is separate from the regular trailer wiring and connector. Here is the isolator/controller I used.

https://www.powerstream.com/battery-isolator.htm

The main advantage of using this system is the use of solid contact solenoid to connect the trailer battery to the Spyder charging system. Some have suggested using a diode to provide isolation. The problem with that is a diode will drop the voltage crossing it by about 1.5 volts. When you're dealing with the 13+ volts needed to charge a battery 1.5 volts can be a big hurdle. The electromechanical relay has close to zero voltage drop across the contacts so you get to use the full charging capability of the Spyder system. Also, this system provides total isolation between the batteries when the bike battery is below 13 volts. You can run down the trailer battery without being concerned about running down the Spyder battery at the same time.

The attached PDF shows how the Power Stream controller is to be connected. You don't have to use their solenoid. I don't remember what I used but it's capacity was enough to handle the charging current to the trailer battery.

View attachment 204576

I like this idea even better than using just a relay only operating when the engine is running. Thanks for the info.

 

[BertRemington]

As I said in my solution, an isolation relay whose voltage sense line is continuously connected to the battery is suitable for automotive batteries but a concern for Spyder (and motorcycle) batteries with their lower capacity and demanding electronics. My solution uses a circuit only draws current when the engine is running. With purchase of the parts needed leaving you with change from a $20 bill.

WRT the voltage drop of a diode, that went out of fashion when we stopped using selenium rectifiers. Please note PowerStream's "solid state 80 amp battery isolator" with a 0.2V voltage drop is a readily available MOSFET diode.

I was also concerned about too high a rate of charge (eg, LFX battery in Spyder, AGM battery in trailer) from the 1KW Spyder alternator which is why I included the option for the 1157 bulb in the circuit.

In the end Mjhitman is going to install the Fatcycledaddy solution and enjoy happy trailering until they pry the Spyder's ignition key out of his cold dead hands.