Battery/Charging question
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Intermediate
Joined: Aug 2016
Posts: 40
Likes: 3
From: Hudson Valley, New York State
Battery/Charging question
I have a 2005 Road King I bought used 2 years ago. I've never had any problems with the battery but recently I installed a detatchable batwing fairing with stereo and now the tender light will never turn green. I'm getting ~13v from the battery. The amp is wired direct but only comes on when the radio is on and the radio is wired to a switchable power wire that only gets power when the ignition switch is on, so I shouldn't be draining it. Am I missing something? Or, is this one of those coincidences where the battery just happens to be going bad now? Anyone have any suggestions? Thanks in advance.
Grand HDF Member
Joined: Jan 2012
Posts: 4,445
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From: Oklahoma
Several possibilities. In spite of your best effort, something might be wired wrong and is placing a constant drain on the battery. The tender may have "chosen" this time to start giving trouble. It is a nuisance to disconnect the battery and reconnect it later and re-set everything, but disconnecting the battery and connecting the maintainer to it will simultaneously check the maintainer and your scooter for a possible electric "leak" if the maintainer turns green as it should. The maintainer is good and the bike needs to have the wiring checked for a constant load. If the maintainer still doesn't turn green, it could be the maintainer or the battery. Put the maintainer on a different battery and see if the maintainer behaves normally. I have replaced several batteries at 2 years because they got "too tired" to spin the engine enthusiastically after a gas stop. They still behaved normally with a maintainer, though.
Extreme HDF Member
Joined: Jun 2011
Posts: 14,731
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From: Mountain Top, Alabama
Connect a known good digital meter directly to the battery still connected to the bike. Observe voltage: does it drop? If yes, pull maxi fuse. If no drop with fuse pulled, chase down the culprit.
Banned
Joined: May 2018
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From: US
Several possibilities. In spite of your best effort, something might be wired wrong and is placing a constant drain on the battery. The tender may have "chosen" this time to start giving trouble. It is a nuisance to disconnect the battery and reconnect it later and re-set everything, but disconnecting the battery and connecting the maintainer to it will simultaneously check the maintainer and your scooter for a possible electric "leak" if the maintainer turns green as it should. The maintainer is good and the bike needs to have the wiring checked for a constant load. If the maintainer still doesn't turn green, it could be the maintainer or the battery. Put the maintainer on a different battery and see if the maintainer behaves normally. I have replaced several batteries at 2 years because they got "too tired" to spin the engine enthusiastically after a gas stop. They still behaved normally with a maintainer, though.
Club Member
Joined: Jun 2007
Posts: 45,429
Likes: 2,897
From: Bedford UK
We get a steady trickle of similar queries after making electrical 'updates'. Other suggestions, in addition to those above: simply disconnect the new electrics you have recently added, especially that direct-wired amp, to see if there is any improvement. As for battery life I have had them last just a few months through to 12 years, so wouldn't rush to condemn yours just yet.
Road Warrior
Joined: Dec 2016
Posts: 1,813
Likes: 894
From: Lincolnshire, IL
I'd first try to check out the battery tender by hooking it up to a known good battery....I suggest your car battery. See if it performs as it should to help eliminate the battery tender as the problem. Coincidentally, just last week my 10 year old BatteryMinder brand maintainer whet bad and I replaced it....stuff happens, so check out the easiest to check out first....the battery tender!
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Outstanding HDF Member
Joined: Dec 2012
Posts: 2,557
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From: Texas
Most motorcycle batteries are limited warrantied for 2 years for a reason...that is their expected service life by design. I also trashed an expensive tender because I forgot to disconnect it before starting the bike. I had the same indication you have, a constant red light and no output.
If it were mine and I was dealing with a suspected current drain problem after installing a hot-wired power amp, I would put a power relay between the amp's unswitched power input and the battery. Use the control from the system to energize the relay. Unless you are drawing 20+ amps current with the audio amp, you should not have any problem finding a relay at your local automotive store. Be sure to put a shunt diode across the relay windings... something like a 1N4004 for example...
There is also a possibility that your charging system just cannot recharge and keep your battery charged while you have the amp powered up, especially if you are cranking up the volume. If the battery never fully recharges, then it will act like you are describing.
If it were mine and I was dealing with a suspected current drain problem after installing a hot-wired power amp, I would put a power relay between the amp's unswitched power input and the battery. Use the control from the system to energize the relay. Unless you are drawing 20+ amps current with the audio amp, you should not have any problem finding a relay at your local automotive store. Be sure to put a shunt diode across the relay windings... something like a 1N4004 for example...
There is also a possibility that your charging system just cannot recharge and keep your battery charged while you have the amp powered up, especially if you are cranking up the volume. If the battery never fully recharges, then it will act like you are describing.
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Thread Starter
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Intermediate
Joined: Aug 2016
Posts: 40
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From: Hudson Valley, New York State
Thanks, Skinman13, that makes sense. Could I use the (ignition) switched power wire, under the seat, that I'm using to power the radio, to power that relay?
I'd like to maintain the detachable feature of the fairing and if I have to run the blue/white wire from the radio, that turns on the amp, back to the battery compartment, I'll have to make a whole new harness. Unless, if I can locate the relay inside the fairing, that would be easy enough.
Sorry for the rambling ...Thanks for the advice
I'd like to maintain the detachable feature of the fairing and if I have to run the blue/white wire from the radio, that turns on the amp, back to the battery compartment, I'll have to make a whole new harness. Unless, if I can locate the relay inside the fairing, that would be easy enough.
Sorry for the rambling ...Thanks for the advice