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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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

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

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.

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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Probably another in a long line of stupid questions.. but do people generally carry a charger when on long tours?

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F650GS twin - Enfield Bullet 350 - Honda XL250 Degree

I never have. Push-starting pillions do weigh more, but I have found them far more versatile.

On a long trip you don't need a charger, so long as

1. you start with a decent battery in the first place
2. you are riding fair distances every day
3. you are not constantly stopping/starting
4. and not using tons of accessories, especially extra lights and heated jacket/grips

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and enlarges the world in which you live," Irving Mather (1892-1966)

Access the Morocco Knowledgebase

Hmm. Well I will have a new battery and I'm not planning on tons of accessories but I tend to amble, stop a fair bit and maybe not ride for a day or two here and there. One time I stored my bike for a month in Thailand. It had an ancient battery and was started fine when I came back to it..

I'm quite taken with the idea of a Lithium battery though and it sounds like they hold their charge much better than Lead-Acid. I guess I will just have to test the battery out a bit before I go and see how much confidence it inspires.

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F650GS twin - Enfield Bullet 350 - Honda XL250 Degree

Your £80 an hour BMW mechanic is telling you porkies or at the very least, speaking out of ignorance. A healthy battery WILL NOT spontaneously self discharge on two days. It is simply not capable of doing this.

No matter how deep the shag pile carpet in these fancy dealers gets the old "they all do that mister" attitude persists - lol.

If your bike is still under warranty take it back and TELL them (don't ask) to sort it out and provide you will a detailed report from the auto electrical technician listing the checks they did. Insist on this check list. Don't accept "no fault found" from these bozos.

If you bike is out of warranty take it to a reputable auto electrician. After they have finished laughing at the £80 an hour Park Lane BMW technician they will test your battery then test stator output, test loads in all states i.e. ignition on/off alarm on/off and any other condition they wish, identifying and quantifying electrical loads and quality of grounds, connectors, terminations etc. From this they will give you a report on what is happening on your electrical system and what you need to do to give you the security you require on your trip. The fixes are often very simple and cost little or nothing.

When they have done this and solved your problem take their report together with your newly fixed BMW to BMW Park Lane and ask them politely to settle the bill from the auto electrician

Motorbike electrics are crap and totally inadequate for out of the way riding. If you are not sparky take your bike to a sparky before the big trip and ask for a check up and their advice.

Include a functioning regulator/rectifier in your spares stash!

I have a question: can you take the battery out of your BMW and still bump start it?

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Hi Fastship

According to Bertrand on another of my threads, you wouldn't be able to bump start without a battery as the fuel system needs some volts to pressurise. Guess this is a downside of Fuel Injection.

The battery didn't discharge in 2 days, it was 8 in fact. Still very short mind you. My guess is that it was the alarm system, reading between the lines of a few comments I've had. This is despite the manual saying that it goes into sleep mode and cuts off after a few days to avoid this exact problem. Maybe my battery is a bit old and then the alarm pushed it over the edge on this occasion. I think I'm going to need a new battery for my trip anyway, so I'm going to get a Lithium one and monitor its' volts and also carry jump leads.

I'm going to call up Park Lane tomorrow and grill them a bit more deeply based on everyone's comments...

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F650GS twin - Enfield Bullet 350 - Honda XL250 Degree

Caution on the lithium batteries ... they "hold" charge better, but generally they have less charge to hold. They deliver tremendous starting power- much more than a conventional battery. I have just swapped my 3kg, 10AH odyssey to a 0.5 kg lithium battery. It starts like a dream. It takes years to self discharge ... BUT the amount of power is is capable of storing is a lot less than the equivalent Lead Acid battery.

i.e. if you are not using ANY current while parked up, the lithium battery will survive better, as it will discharge much less and still give you that massive starting power whenever you turn to it. But if you have an alarm on for a week, without riding the bike, a lithium battery will discharge faster, because it doesnt store as much power as a Lead battery and your alarm will use up the charge in a Li battery faster than it would on a larger heavier Pb battery.

So as for what is better, it depends on how you use it.

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Isn't it just about the Ampere-hours? ie if you have a Lead-Acid battery and a Lithium battery both rated 14Ah, they should discharge at the rate rate - 1 amp for 14 hours or 0.5 amps for 28 hours etc.

Or maybe I'm missing something?

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F650GS twin - Enfield Bullet 350 - Honda XL250 Degree

...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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Albert