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Advice, Second Battery for R1150RT

jsoque

New member
I've often wondered if I need a second battery in my '04 R1150RT for operation of my gadgets, and Gerbings heated clothing.

Has anyone had any experience with wiring a second, 12 Volt, Lead Acid Sealed battery, into the 'Radio Compartment' box of an RT?

I imagine that the hook up is in series, that is plus to plus, and minus to minus to the bikes main battery.

Then there is the charging factor; and does my alternator charge this battery at the same time the bike is operating?

(I can hear your thoughts now: Oh No, this guy's headed for trouble...)

However, I would appreciate any input, as well as choices for a battery purchase of the many that are out there.

As for the project, I'd imagine that it would involve me removing my L side tupperware, and running some heavy guage wire to the main battery, before I run some splits off for my GPS/Iphone charger/Gerbings heated clothing.

Any advice is much appreciated,
(and believe you me, I won't start this project without all of you involved, 'cuz Vince would kill me, and also, I don't want to come out to my garage, to a melted bike')

Ride Safe, Stay Warm

Jim
on Long Island, NY
 
"I imagine that the hook up is in series, that is plus to plus, and minus to minus to the bikes main battery."

This is actually parallel and yes, that's how you would do it , stay at 12 volts and get double the amperage (assuming identical batteries). I think police bikes came this way.
 
Some police bikes came with two batteries. That was so lights could flash a long time with the engine off. Most RVs have a similar setup - engine battery and one or more coach batteries.

RV setups have either a relay isolator or a diode isolator so the alternator will charge the coach batteries but the lights, etc. won't drain down the engine battery. I don't know if the police bikes had that or not.

That said, a second battery is not the answer to powering gizmos if you mean while you are riding. Not for very long at least. If the current draw from all of the devices plus the bike exceeds alternator output two batteries will just give you two discharged batteries instead of one.

Now, the alternator really likes to see 2,000 or above rpm for peak output, so if you do a lot of putting around with starts and stops at low rpm the second battery would be a bigger reserve, but for most riding it wouldn't gain much of anything except add weight.

Your R1150 should have a 700 watt alternator. On my R1150R that is sufficient to power two 55 watt driving lights, two 55 watt Motolights, my Gerbing heated jacket liner, the heated grips on high, and all bike house loads including high beam headlight. I don't even count the two GPS units and radar detector because those loads are miniscule.

If you are having battery discharge issues it is because the battery is bad, the charging system has a defect, or you have a drain someplace unless you are riding around a lot at very low rpm.
 
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"I imagine that the hook up is in series, that is plus to plus, and minus to minus to the bikes main battery."

This is actually parallel and yes, that's how you would do it , stay at 12 volts and get double the amperage (assuming identical batteries). I think police bikes came this way.
The police bikes have a Heavy Duty Relay isolating the two systems so Battery #2 may be discharged without affecting #1 when the bike is off.
 
I really don't think you will discharge your single battery on an R1150RT with the normal amount of add on's that I have seen. If you are really worried about a dead battery I believe the way I would go would be to get the R1150RTP's 840 watt alternator and install it. It should be an easy drop in replacement. They show up on eBay ever so often. I thought about doing that but I have never had any problem with running 2 electric vests, heated grips, gps, satelite radio, intercom, extra low wattage lights, and a heated seat.
 
yes, over kill

Your gizmos aren't drawing enough power to justify all the crap you would need to go through to add a battery.
 
Two batteries = 2x the trouble

I've put 56,250 miles on my RTP over the past five years, and at this point, I'll have to say having two batteries doesn't provide enough bang for the buck.

The 2nd battery in the left-side glove box/radio box puts a big chunk of weight high up on the bike. The wiring to accommodate the 2nd battery adds unnecessary complexity to an already complicated wiring harness. Trouble-shooting electrical gremlins becomes more difficult with two batteries.

I've often contemplated removing the 2nd battery from my RTP, and going with just the main battery under the tank.

I'd recommend against it. Your RT's alternator and one battery can handle the lights and heated gear.
 
Yeah, that second battery is just there for the extra police equipment that may be on while the bike's ignition is off- emergency lights, radio, radar, so the main battery doesn't get drained and the bike starts after the motor vehicle stop or whatever the officer was on.

As has been said, a single good battery and alternator will be able to power anything you can mount, within reason.
 
+1 on the previous comments. 700 Watts is plenty of power for heated grips, clothing and some other accessories. I've ridden with guys who can warm the back of my head up with the lights and gadgets all powered from a stock electrical system. :laugh

Officer Impersonator mentioned the extra weight, wiring and maintenance associated with dual batteries and that alone is a good reason not to do it!

That glove box is super handy on the road too.
 
Once the bike is started the battery size does not matter.

The alternator should carry the whole load and recharge the battery from starting the bike.

Unless you plan on having things on with out the bike running I can't see where the extra battery would help at all.

David
 
Keep in mind, though the battery will be charged when riding, only when the RPMs are over 2,000, some bikes need 2,400. Below that, you're sucking the juice out of the battery.
 
Ladies and Gentlemen, and Happy Wanderer - how'r the mirrors I sent you last year?

I received a replacement battery, a Yuasa 51913, old style, and had the dealer add battery acid for me.

Took off the tuperware on the L side, and also received a phone inquiry back from the previous owner, and friend. He said my gel battery was replaced in 2010, and so, I thought, it was about time anyway... and took it at face value.

With regard to my gadgets, he reminded me that there was still a GPS line laid in back in 2005, and I might find this key'd line useful for my gadgets in the bag.

I had a dedicated Gerbings charge end dedicated from the battery source originally to power my either, tank bag outlets (2) or, my Gerbings heated clothing.

So, I traced the old GPS line, and ran a new plug from that, for the Tank Bag, and now that takes care of the charger to the Iphone, and the Garmin GPS.

I switched out the battery, and reassembled the battery box, leads, and kept the plugs for my Gerbings heated clothing near the seat moulding.

I closed everything up, and gave it a charge/trickle charge overnight. Then, I tried out ever yesterday. 41 degrees at 3 pm, and sun at 30 degrees.

Plugged in the Iphone, GPS into their charging spots, and all the lights worked.
Then, I plugged in my Gerbings Jacket, Pants, and Gloves into the temperature controller, and planned to ride 50 miles to JFK airport at 4 pm from the center of Long Island.

I had a turn around at the Ocean Beach Parkway, bc, it is still closed from refuse on the road, etc, from Hurricaine Sandy. But, I got back on Rte 27 West, and made it to Jones Beach, Long Beach, and then up and over to the estuwaries.

All of my appliances got their charge, and my heated clothing opperated without failure. Home by 6:15 pm, 100 miles under foot.

I put her up on the center stand, and enjoyed the evening.

After a full day of work, I thought, 'Let's see how that new battery is doing?"

Just back in from the garage, I can successfully say that all of your advises paid off, and the new battery, and clothing and accessories work just GREAT !!! The lady started right up, and no hesitation at all, not even without a repeat charge.

No second battery needed, and so I will continue my cold weather riding in this manner, one main battery only, for the time being, at least.

I can't thank all of you 'enough', and perhaps, if you are around Long Island and see a Charcoal Grey RT with a rider in a Silver Schuberth, and a hint of 'Neon Yellow" with a lit up Givi 52 topcase, you'll give me a beep, or a wave, or a Thumbs Up
for contributing to this thread.

I only hope our members will learn from this exchange of information, and create for themselves, a better ride!

See you out there, and Stay Warm!

Thank You again, One and All!
~I think some of you had as much fun responding to me, in as much energy as I had anxiety brewing!

Gobble, gobble, gobble...

Jim
 
As I mentioned earlier, my 2nd battery is dead (5 years is about the normal life expectancy of a battery).

I'm sure I'll be posting a similar report noting how I have no issues running my radar detector, GPS, cell phone, iPod, and PIAA 1100xs off the main battery instead of the soon-to-be-removed auxiliary battery. I don't use heated gear.

Heated gear is for wussies and/or people who don't know how to properly layer the proper layers of clothing. :brow

But that's just my opinion.
 
Ladies and Gentlemen, and Happy Wanderer - how'r the mirrors I sent you last year?
Jim

Glad to hear you are warm and toasty Jim. Heated clothing is not "just for wussies". It is also great for people who want to stay warm and alert while riding. :D

The mirrors? Well, when I got them I learned something. 1150 GS mirrors do not fit on an 1100 RT as I thought! So I sold them to a happy camper in AZ who has an 1150 RT and is thoroughly enjoying them.

It took me a while but I found two 1100GS mirrors on eBay at two different junk yards. They help rear visibility enormously.
 
Side Mirrors

Glass is cracked on right side mirror. Can I get a replacement or do I have to buy the whole gizmo?

Peter
 
Glass is cracked on right side mirror. Can I get a replacement or do I have to buy the whole gizmo?

Peter

It is possible to replace just the glass on an RT. There are pop in tabs on the plastic backing of the mirror.

For the GS however it is not really possible because you will destroy the plastic bezel around the old glass getting it out.
 
I've often wondered if I need a second battery in my '04 R1150RT for operation of my gadgets, and Gerbings heated clothing.

I can't see why you would need to unless you are powering all your gadgets with the engine off...or you are in "silent watch mode" off on the battle field.

You have a 700 watt alternator that can keep up with your power draws.
 
Auxiliary Battery

The auxiliary battery on my R1150RT was dead and drained the main battery.
i'm taking it out and using the compartment for storage but can't get the battery strap unhooked. Looks like a bolt
holding the strap but hard to see. Can anyone help?
Peter.
 
...

That said, a second battery is not the answer to powering gizmos if you mean while you are riding. Not for very long at least. If the current draw from all of the devices plus the bike exceeds alternator output two batteries will just give you two discharged batteries instead of one.

Now, the alternator really likes to see 2,000 or above rpm for peak output, so if you do a lot of putting around with starts and stops at low rpm the second battery would be a bigger reserve, but for most riding it wouldn't gain much of anything except add weight.

...

+1 on the above. Also, for low RPM starting of the alternator, you should check that you have a 3W bulb in the Batt indicator lamp. Mine was only 1.7W and I accidentally discovered that BMW seemed to have changes the spec somewhere along the line.

The best function of a second battery is that when installed in the left-side-of-tank storage compartment, its 14 lbs. weight better balances the motorcycle, eliminating a slight pull-to-the-right that most R1150RTs exhibit. I didn't realize mine did until someone pointed it out. That PTTR can be well mitigated by 12 lbs. of lead shot in the compartment which fits in the bottom inch of that box. You'd be surprised at the difference.
 
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