Auxiliary Battery

[pancho]

I was cleaning up the wiring mess and relays I have accumulated under the right side cover with an aux fuse and relay panel when I got the idea that I would like to run the stereo when the bike was not running with no fear of draining the battery. I built this panel which is under the seat and lifts out to the side for removal of the battery or any other work in that area.



I put a 7AH battery in the right saddlebag (I may add a second one depending on how much playing time this one gives me).



and wired it with a switch (mounted on the relay panel) that in the "RIDE" position will be in parallel with the main battery and stay charged, and the electronics in the fairing will work as normal. When the switch is in the aux. position, the stereo will work with power supplied from the auxiliary battery only, and the key off,, if it is drained, you only need to turn on the key, start the bike, flip the switch back to "RIDE" and be on your way. The AUX battery will be charged back up in awhile. The circuit is very simple if anyone would find this useful,,, I  think I will get a lot of use from it.



Now to loom and secure all the wiring, put it back together, and get into that petcock and see what I find... mine is also dripping when in the off position, and flowing without a vacuum...

[big poppa pump]

Cool idea.

[Louis Durocher]

How did you find place for the panel, it must be a Tourer with no radio under the seat. I cheked my Interstate and find no room there.

[pancho]

I did this on a standard Louis, with Tsukayu fairing and bags. The stereo is in the fairing and the area under the seat is clear.

good picture BPP,, I like the matching oil filter

[KY,Dave (AKA Misunderstood)]

Nice work  Sure wish I could keep my bike that clean 

[bentwrench]

You might want to look into one of those new L-ION power packs.Alittle price but several time the output of that 7ah batt with no weight and space penalty.I'll be carrying one in my saddle on trips this year just in case.

[pancho]

Nice work  Sure wish I could keep my bike that clean 

Keeping it clean is not much of a problem,, getting it clean when I brought it home two years ago was another story,, took an extensive teardown to get to everything for inspection and maintenance.

While a Li-ion battery has a higher power density, there are several reasons why I decided to use a lead acid gel cell for this mod bentwrench,, mainly ease of the recharging requirements, 12 Vdc to 12 volt Li-ion smart charger is expensive and requires space,,  it is only used to run the sound system when the bike is stopped, otherwise it is part of the overall battery capacity and part of the bike,, I already had the Gel cells laying around (free),  the three or four pounds of the battery are nothing on the Valkyrie, and 7AH will run the stereo and battery meter without an amp at output levels required with the bike not running for quite awhile, as it draws way under 1 amp under those conditions.

I wonder, are you planning to carry that battery loose for a starting emergency, wire it into the bike, camping lights and accessories, or what? Pretty good idea to have a 12 volt source with you, but only if you can charge it.

[KG]

Look at the wire from the bike battery that connects the main battery to the Aux battery to charge the Aux battery while the engine is running and  the relay is in the ride position. You need  to add a diode to that wire.

 In the case of normal starting or a low main battery with that relay closed to normal ride  it will try to pull current through that wire to help start the bike. this may overload the size wire you used  and/or damage the Aux battery.  The Diode will prevent this by allowing main battery voltage to flow to the Aux battery/stereo and stopping it from going in the reverse direction

[pancho]

Good catch KG,,,

It is planned to work that way (with the aux battery being part of the overall capacity) and it is wired with 12 Ga. multi strand copper, 40 amp switch, and fused at 10 amp at the auxiliary battery.  That should prevent any problems if the main battery gets into any trouble. If I do start to have problems with it blowing the auxiliary battery fuse , I will add a diode,,      thanks

[KG]

If you install a full size or larger battery in the saddle bag you could use a larger solenoid and wires with a switch for a built in boost pack in case the main battery goes bad.

I think you will also have to watch how low you allow the aux battery to be drained as most don't like to get below 70% without shortening the life of the battery.

[pancho]

I agree with you about the battery life KG, to make this fully functional for the long haul I may eventually need to change the battery composition as bentwrench suggested. I had these gel cells laying around getting old so that is what I used, we will see how long it lasts getting partially drained down before recharging.  There is a voltage meter to monitor the battery in use, but I'm not sure how helpful it will be.

[DK]

I know very little about electricity, so here goes,

1)  Do I correctly understand that the LI ion power pack cannot be charged by the Valk alternator?

2)  Will a "battery maintenance" charger charge the power pack along with the Valk battery?

I intend to carry a power pack with me on trips. Assuming it cannot be recharged while traveling, it would seem that a higher capacity pack would power a radio/MP3 & recharge a small iPad quite a bit and still retain sufficient power to start the Valk in an emergency.

I would appreciate any help on this.

Dan

[pancho]

You can use a Li-ion battery power pack to do everything you want except possibly to charge it directly from the bikes alternator DPK.  Li-ion batteries are a bit touchier than lead acid batteries when it comes to recharging, and while there are DC to DC Lli-ion chargers available, you need to check with the manufacturer of the specific power pack you are buying. Some of them are pretty smart and could be connected up to the charging system, many will require their specific charger plugged in at a hotel or campground.  Also make sure you get one of the correct capacity if you expect it to start the bike.

[Ricky-D]

To carry an extra battery that cannot be charged by the bikes charging system is dumb.

***

[DK]

Thanks Pancho. You answered my question.

Obviously, unless I can charge it from the Valk it would be of little use.

Again, thanks.