Avoid Motobatt - one in my TZR lasted less than 2 years, it has bugger all to drain it, gets light use, regularly topped up - not sure if leaving bikes on permenant charge is or is not good, so I generally put all the bikes on charge for a day or 2 once a month over the winter.
OE battery on my KTM lasted ~5 years (maybe 6 years if you account for it being a 2018 bike bought in 2019) Mrs TDM we have had 12 years now it has only had two batteries replaced, my memory is not what it once was, but last one was a good few years ago, so I am guessing roughly 5-6 years is our typical life under that maintenance routine.
All modern bikes draw some power when "off", and extra's can make it worse, you do not say how often it gets ridden, if you are leaving it for months then a flat battery may be normal, and if they go too flat they tend to become shagged.
Also is the charging system OK even? might not be a drain on te battery, but it not being properly charged, or over-charged?
As stated check what you have added, and if they are on a switched live, if you have a sat nav power pack fitted and wired to permentant live / direct to battery....
....The draw is very small IF you remove the nav from the cradle, but if you forget to remove the device it will fuck a battery pretty quick, even if you remembered to turn the nav off (Ask me how I know!)
You might find using AI is quicker and easier than this forum, with less innacurate information, useless anecdoted or endles spiss taking, but where is the fun in that;
- Leaving the GPS in the Cradle: Leaving a zūmo 390 or 590 locked in the cradle with the bike engine off changes everything. Even if you turn the device "off", it often drops into a background standby or charging state, drawing 2.5 mA to 3.5 mA continuously. Over a few weeks of winter storage, this will drain a small motorcycle battery. [1, 2, 4]
- Can-Bus / Accessory Circuit Confusion: Many riders wire their Garmin mounts into factory accessory plugs (like the BMW CAN-bus plug). Some older BMW bikes fail to put the accessory circuit to sleep if they detect any resistance on the line—meaning the bike’s central computer stays awake at 100+ mA, draining the battery overnight. The fault here lies with the bike's computer logic, not the Garmin cable
(FYI: off in cradle is ~25 times more draw than removed from cradle)
I have focussed on a Garmin as an example as I have no idea what you have fitted;
On a
2014 BMW R1200GS (Liquid-Cooled "Wethead"), the issue is almost certainly caused by the bike's
CAN-bus ZFE (central vehicle electronics) module refusing to go to sleep. [
1]
When you wire a Garmin power supply into the factory front accessory/GPS plug (located near the headstock), the bike's computer monitors that circuit for resistance. The tiny standby current of the Garmin converter fools the BMW computer into thinking a critical accessory is still active. Instead of shutting down the circuit 60 seconds after you turn off the key,
the bike keeps the entire sub-bus awake, resulting in a massive
100 mA to 150 mA parasitic drain that flattens a healthy GS battery in 3 to 5 days. [
1,
2,
3]
IMPORTANT: AI can supply wrong answers, and in this case it has found some of this information somewhere on this forum, increasing the chances of it supplying utter bullshit ;-)
Step-by-Step Isolation and Fix Strategy
To confirm this and permanently stop the drain on your GS, follow this diagnostic process.
1. Perform a Target Amperage Test
Before tearing things apart, check if your bike is actually entering sleep mode. [
1]
- Access your battery, shut off the ignition, remove the key, and wait at least 15 minutes without touching anything (do not operate switches or open the luggage). [1]
- Hook up a digital multimeter in series with the negative battery terminal to read DC milliamps. [1, 2]
- The Target Profile: A healthy, sleeping 2014 GS without an active alarm should drop to less than 5 mA. If your multimeter stays locked at 40–150 mA, your CAN-bus system is stuck awake. [1, 2, 3]
2. Confirm the Garmin Fault
- Unplug the Garmin power supply adapter entirely from the BMW harness or battery terminal.
- Wait another 15 minutes for the bike to cycle down.
- If your multimeter suddenly drops down to the healthy <5 mA zone, the Garmin cable's footprint is officially keeping your ZFE module awake. [1, 2, 3, 4]
3. Choose a Permanent Solution
If the Garmin plug is causing the CAN-bus lock, you have three highly reliable ways to fix it permanently:
- Option A: Wire to a Switched Fuse Block (Highly Recommended)
Install a solid-state power hub or an accessory fuse block. Wire the trigger wire of the fuse block to a definitive switched source that does shut down cleanly (such as the rear diagnostic plug power or the license plate light). Hook the Garmin to this fuse block. When the ignition drops, the power to the Garmin cable physically breaks, forcing the circuit dead.
- Option B: Add a Dummy Relay
If you insist on using the factory front GPS plug, splice a standard 12V 4-pin relay into the circuit. Use the factory plug power only to trigger the relay coil, and route the main power line directly to the battery with an inline fuse. The microscopic drop across the relay coil is usually ignored by the CAN-bus logic, allowing it to shut down normally.
- Option C: Use a Can-Bus Control Module
Install an aftermarket CAN-bus management module. These intelligent systems plug directly into your GS's data bus, safely reading vehicle states to give you perfectly timed, clean, switched circuits for GPS units, radar detectors, and auxiliary lights without triggering system alerts or sleep faults.
Key Electrical Benchmarks for a 2014 GS 1200
- Normal Bike Sleep Current: < 5 mA
- CAN-Bus "Stuck Awake" Current: 40 mA to 150 mA
- Healthy Starting Cranking Voltage: > 9.6V
- Healthy Running Charging Voltage: 14.2V to 14.5V [1, 2, 3]
How is your Garmin power supply
currently connected to the bike—is it plugged into the factory GPS plug behind the dash, or wired right to the battery?
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