LT with trailer - add spare battery - K-Bikes.com - Excellence in Motion
 
LinkBack Thread Tools Display Modes
post #1 of 7 (permalink) Old Jul 9th, 2007, 1:34 pm Thread Starter
Noob
 
Join Date: May 2004
Location: , ,
Posts: 5
LT with trailer - add spare battery

Here's a good one. An LT rider, with trailer, I know wants to have a secondary MC battery available to charge his laptop, phone and other accessories left on the trailer during overnight camping.

His question is what is a good solution to keep the secondary battery charging while going down the road. Should he hook it up with the primary and let the bike charge it? One idea passed on was to add a power inverter and trickle charger to his trailer circuit.

Something tells me having two batteries active on the bike's circuit is not a good idea. Any electrical gurus out there have an idea? Thanks in advance.

Keith N.
98k12 is offline  
Sponsored Links
Advertisement
 
post #2 of 7 (permalink) Old Jul 9th, 2007, 3:03 pm
Enthusiast
 
MikeK's Avatar
 
Join Date: Jun 2003
Location: , ,
Posts: 377
an inverter pulls several amps (depending on its capacity) to operate, IMHO thats no solutionat all.

Providing he is not already maxxing out his charging system, then pigtailing the 2nd
battery parallel to the existing motorcycle battery will work fine. Done on diesel trucks everyday.

Years ago Brian Curry (a REAL electrical guru) calculated that a K1100 needed 250 watts of power to operate the FI, ABS, and lights (house load).

No idea about an LT's alternator capacity, but a K12RS's alternator capacity is 600watts IIRC.

Mike Kelly

Triple M Engineering

K12RS

Stanley, NC
MikeK is offline  
post #3 of 7 (permalink) Old Jul 9th, 2007, 3:20 pm
Looking for better limits...
 
Razel's Avatar
 
Join Date: Jun 2003
Location: Fremont, CA, USA
Posts: 5,163
You might look into a battery isolator. Their original purpose is to protect a "starting" battery from deep-cycle batteries used to run other electrical items. The charging circuit will charge all, but the starter (or in this case, the motorcycle battery under the seat) battery won't be tasked by the load on the other side of the isolator. So, the second battery can be used to power the items in the trailer, and if it runs down, it won't pull any from the primary battery...and you can start up the bike in the morning (and start charging up the second battery).



100% free webcam site! | Awesome chicks and it is absolutely free! | Watch free live sex cam - easy as 1-2-3

Ray
2010 K1300GT Royal Blue
2003 K1200GT Orient Blue (for sale)
2007 G650 X-Challenge

IBA #34158

Be a K-Bikes Supporter

I work for Keyser Söze
Razel is offline  
Sponsored Links
Advertisement
 
post #4 of 7 (permalink) Old Jul 9th, 2007, 3:39 pm
Addict
 
carnadero's Avatar
 
Join Date: Dec 2005
Location: Sillycon Valley, CA, USA
Posts: 645
This might sound crazy, but assuming that the person is confining his actual road time to the daylight hours and using the laptop in the evenings after making camp, how about a solar panel to do the charging while he's motoring along in the daytime?

Seems to me that upon waking up in the morning, he's gonna break camp and hit the road, right? If so, having a fully-charged laptop battery in the morning isn't going to be of any real use unless he intends to fiddle online the next few hours after waking up. Me, I would typically want to get going, and the full charge would be most useful at the end of the day's ride.

Black 2002 K1200RS - "The Beast" (over 100k miles)
carnadero is offline  
post #5 of 7 (permalink) Old Jul 10th, 2007, 4:04 am
Addict
 
Join Date: Mar 2004
Location: , , UK
Posts: 3,750
On the inverter issue, if his voltage source is 12 volt, then he's got to have an inverter somewhere since most laptops and phones won't operate direct from 12 volt. Electric shavers also may not operate direct from 12 volt. Most ac electronic inverters can reach 85% efficiency now and I'd factor one in - just for that occasion when you may use a shaver or something for a short time, but definitely not for charging.

I'm guessing the trailor and camping activities are seasonal and at certain times of the year the battery will be laid up. Solar power is a good idea for trickle charging but you'll never get that rapid charge equivalent to an alternator or riding for an hour. The choice of battery might be relevant too. If you go wet cell, then it must be tendered 24/7 on and off the trailor. A nicad (not Nimh) is more expensive, but it holds its charge for longer. The lowest cost option is to go wet cell or even an Odysee if your friend can aford it. Solar power is probably best combined with using the bike's alternator.

The first thing your friend should do is make sure they know what voltage and current is needed for each device they intend to use - most laptops for example are around 18 volt. Electronic inverters work best when they are dc to dc close to the voltage you need. So a 12 volt adaptor for a laptop would invert 12-18volt and be very efficient. The same is true with a phone - 12-5 volt would be efficient BUT make sure the converters are the small electronic switching types. Now the charging circuit for the auxiliary battery needs to be looked at carefully else there is a risk the bikes battery will become flat and LT's with trailors are hard to push on grass!

I wouldn't allow the auxiliary battery to take any power from the bike when the bike isn't running, so that would need a relay connected to the parking/running light. Then there must be something like a diode between the bike and the auxiliary battery to stop auxiliary power going backwards when the bike is started or its battery is low. Next, you can't use the bikes own regulator to control charge into the auxiliary battery which now has a diode attached. I think there are products around which will isolate the primary battery, include an inverter to boost voltage from 12 to about 16 to charge the auxiliary battery. Consider that the auxiliary battery if run nearly flat could take 10-15 amps at the start of its charging cycle. But that's no probs for the big alternator. I think this is what Razel was referring to, I just explained why it's needed.

I'd look into auxiliary battery charging products used by the RV and trailoring people. You might start thinking your friend has a simple question, but a proper solution needs more than a bit of hookup wire and a resistor. Then you have to use thick wire gauge due to length from the bike, consider safety fusing at the auxiliary battery outlets and the bike charging feed.



Never pay again for live sex! | Hot girls doing naughty stuff for free! | Chat for free!
voxmagna is offline  
post #6 of 7 (permalink) Old Jul 10th, 2007, 11:05 am
Addict
 
carnadero's Avatar
 
Join Date: Dec 2005
Location: Sillycon Valley, CA, USA
Posts: 645
Quote:
Originally Posted by voxmagna
On the inverter issue, if his voltage source is 12 volt, then he's got to have an inverter somewhere since most laptops and phones won't operate direct from 12 volt.
Not necessarily in the case of laptops and cell phones. 12V power adapters can be had for just about any laptop and fone. I picked up an aftermarket unit for my Vaio laptop and my cell service provider listed a cigarette lighter plug in cord for the Motorola unit I have.

Black 2002 K1200RS - "The Beast" (over 100k miles)
carnadero is offline  
post #7 of 7 (permalink) Old Jul 10th, 2007, 1:14 pm
Addict
 
Join Date: Mar 2004
Location: , , UK
Posts: 3,750
Those cigar plug 'adaptors' are often switched mode inverters built into the plug! At least the small ones usually are. The wall socket power supplies if large and heavy are not switch mode and have lower efficiency. Your small laptop power unit that runs off the mains supply is actually a switched mode inverter power supply. If you look at the input voltage range, it's far too wide to be a transformer and simple dc regulator.

So you see, you can't get from 12 volt DC to a stable regulated 'any other dc voltage higher or lower' without a converter and the most efficient are the switch mode inverter type power supplies disguised as a cigar plug - but full of electronics.

The exception is when a laptop manufacturer provides an input for 'raw' car 12volts, but they'd assume any voltage from 8 to 16 volts and the inverter would be put on the motherboard. Most satnavs do this, but your pda running off 5 volts would need a cigar plug switching converter if it ran off 5 volt.



Never pay again for live sex! | Hot girls doing naughty stuff for free! | Chat for free!
voxmagna is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the K-Bikes.com - Excellence in Motion forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Battery cooking polowonder K1200RS/GT (Classic) 14 Jul 25th, 2018 8:18 pm
BMW G2 GT Battery Charger-At Last! pmorritt K12/1300GT (Next Gen) 13 Dec 6th, 2008 7:12 am
Stability and Uni-go trailer (Long) K1200rspd K1200RS/GT (Classic) 25 Aug 31st, 2008 7:26 pm
putting neg- battery terminal on first before pos+ hilltdm123 Technical, Repair and Maintenance 5 Apr 16th, 2007 11:09 pm
Battery Charger For K1200S: Word from Deltran Pirate K12/1300S 15 Dec 23rd, 2005 7:25 am

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome