I left my F650GS twin for a week and came back to find a flat battery. Just before this I had had an annual service with BMW Park Lane so I called them and was informed that this was a normal enough period for the battery to discharge. They said a new battery might do 2 weeks but mine at 2.5 years old, one week was par for the course. Can anyone confirm? Seems mighty short to me. I have to add that the alarm was on (although it is supposed to sleep and then switch off to avoid this issue) and I had a GPS cable (not unit) plugged into the accessory socket (again, theoretically not a problem as the socket is supposed to switch off 15 mins after ignition off)

I am heading off for a year around South America in a few months time and might well have periods where I don't ride for a week or more - so should I carry a solar charger? I am thinking of getting one for home (no power socket availability where I keep the bike in my front garden)

Or does it sound like my battery needs replacing? BMW Park Lane said it just passed their tests...

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http://www.guyfixsen.com
http://wanderinggoo.blogspot.com
F650GS twin - Enfield Bullet 350 - Honda XL250 Degree

Hi Goo, I would change the battery before setting of to southern climes. If you travel like I do which means stopping and starting a minimum of 15-20 times a day, pic, food, pea stops and giving your back a break, the battery gets a real hammering and having just taken a magnificent pic of the hands in the middle of the Atacama desert, being greeted with only a click when you engage the propulsion unit energising sequencer can spoil you whole day. As regards the alarm, I stopped using the alarm on my 1200GS except for on short stops in UK crime ridden towns and cities using it when the bike was parked up for 2 days just flattened the battery. Buy an alarmed disc lock and if that flattens your battery you really do have problems. I'm off to S. America myself in about 6 weeks, might see you there. Ride safe.

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Mike
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Mike is riding the twisty road in the sky

Interesting.
Thought BMW had eliminated that "sickness" since the /7 series...

Odyssey batteries keep the charging far better than standad acid batteries.

Still, in 1-2 weeks?!... just as it were with the /7 standard 18-20A alternator and prone to be shorted diod-board...

Happens when there is something pulling/using current, like a bike-alarm, /7 diod-board, bad wires, etc.

Good idea to bring a solar-cell-charger!
Look at options with flexible solar-cells to cover the topbox with - I think that might be a good idea/solution

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Drive Safely,
Albert

Solar power .....
One has to admire an optimist Albert
cough cough

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I do not list my vehicles or the places I have travelled to nor do I live my life seeking validation from others.

I've found that on average a motorcycle battery only lasts me maybe 2 or 3 years - and I've found that they can turn from good to bad at the drop of a hat. They need regular replacement just like other consumable parts.

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Bruce Clarke - 2020 Yamaha XV250

Motorbike batteries are quite small and can't withstand multiple deep discharges, so it's a good idea to connect up a trickle charger from time to time to keep them topped up and extend the life of the battery. Otherwise the sulphur molecules in the battery acid that are not reactivated instead start to coat the lead plates.

I have an F650GS twin which is coming up for 2 years old. The battery isn't particularly accessible so I wired in a connector coming out near the headstock to make the recharging easier which I do every two weeks. I should really do this more regularly but like you the bike is outside the house, so I have to run a long cable over the garden. I'm finding that it currently takes a couple of hours to bring the battery to full charge, so it looks as if my battery will need replacing before too long. As bclarke says above, batteries go from OK-ish to buggared overnight.

Best thing for your trip is to (1) replace the battery beforehand, and (2) take a multimeter and check the battery charge every few days (again, wiring in a connector will help make this easier). A 12v battery should show around 14v when fully charged. Once it gets below 12.5v sulphation starts in ernest. The good news is that getting a suitable replacement battery on the road isn't as difficult as I would have thought, though getting one to fit neatly can be more of a problem.

Several times I've been with people when their battery has discharged so much when riding offroad that it won't start. The cause is normally stop/start riding, especially with auxillary lighting, heated grips and so on, but also forgetting to turn the ignition (and therefore headlight) off when the engine isn't running.

One of the really nice things about the F650GS twin is that when the engine stops running the headlight switches itself off automatically (marvels of CanBUS) even when the ignition is still on, so you won't get so much of a problem in this area.

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"For sheer delight there is nothing like altitude; it gives one the thrill of adventure
and enlarges the world in which you live," Irving Mather (1892-1966)

...I did mean as a back-up system for charging whilst parked, not as primary energy sorce for driving...


To use a solarcell as substitute for gas/petrol, now -that- would be a bit optimistic, still there is an annual race across Australia with solarpowered vehicles.




Lets enjoy the techinological development of vehicles.



On the Swedish market, for cars, I know of these two options:
Solcellspanel f�r bilbatteri 17,5 V 1,5 W - Jula Online – Allt för ditt hemmaprojekt!
1.5W... that is too little to make a difference less used over several days...
13W is far better, but far from what is really needed:
Solcellspanel i v�ska 12 V 13 W - Jula Online – Allt för ditt hemmaprojekt!

These are not just plug-in gadgets since they deliver 17V.

Back in the 80:ties I was taught that one should use about 10% of the batterys capacity as charging current - this may well have changed since then though; but is gives a hint of the need.

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Drive Safely,
Albert

I find it really odd - it appears modern bikes discharge their batteries its something you hear a lot of all the time - maybe its alarms and all the gizmos people run, maybe they have poor batteries, Other than a Moto guzzi I owned most of my bike including Laverdas, BM airheads, Cagivas and KTM to name a few have been used for everything from daily rides, for commuting and as everyday transport as well as long haul travel bikes never really suffered discharged batteries in storage and very rare has it been when I have not been able to start a bike off the button or the kicker. I have never used these trickle charge gizmos, never ever had an alarm on a bike - that's i think is just asking for trouble and have always done good maintenance on the electrical system ie kept fitting and plugs well cleaned and lubricated with electrical grease, earths kept clean , battery terminals cleaned and greased, once a year seems to keep on top of it all - that includes winter riding - so I think the bike you have must have a leakage to earth through a bad connection, broken wire or something is staying on and agree a good auto electrician should be able to sort the problem. But if it were me I would get rid of the alarm, clean and lubricate every electrical connector, check where you can for possible broken wires or shorts, take your battery off give it a good charge and get a drop test carried out at a local car shop, if that seems ok you may have solved the fault if not the auto electrician is the man to turn to next. I would not be inclined to trust BMW main dealers they are not auto electricians there 'mechanics' are mostly fitters of sorts, cost too much and often have neither the skill or the experience and knowledge of a good auto electrician. Good luck with it though.