Big pile of dogshit

[knutk]

Some thoghts around starting issues and batteries:

Back in my 'old' days, I used to mess about with medium sized TurboProp engines. They could be cranked up either battery power or ground power. The starter was a DC motor.

Since a DC motor, before it starts to rotate, offers hardly any electrical resistance (when it turns, induction lowers the current draw). Thus, it was a big issue to limit ground power units to a maximum Amp output. ( A typical number could be 1000 A). This in order to protect the starter motor as well as the entire start up circuit.

I'm not sure if this is a issue, but could it be that introducing batteries with larger CCA than OEM will introduce a heavier start-up current and thereby damage the starter relay?
Sure, the engine will spin up faster, but is the components in the bike able to handle it?

A new and well tuned 1200/1250 engine does not have a starting problem. Could it be that the more powerful battery actually contribute to just hide a problem that normally would be noticed by the engine strugeling to spin properly?

I'm not saying that this definitely is an issue, but any chance that there is a connection between larger battery and development of other problems in the future life of the bike?

 

[Pukmeister]

BMW offer a lithium battery as a cost option, so they expect the starter motor to handle inrush from a lithium cell.

I replaced the starter relay in case its contacts had arced/pitted and caused an unwanted volt drop across them.


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[Pukmeister]

Just rode home ten miles then stopped for petrol, exact same journey as my last hot start problem. Bike burst back into life without hesitation using the new hybrid battery. I’m very pleased with it.

 

[Bigcats]

Like Pukmeister I have just fitted the same battery ordered and came next day from these guys (as already posted)

Motobatt MHTX16 Hybrid Lithium Battery YTX14-BS PC545 YTX14L-BS

Shop Motobatt MHTX16 Hybrid Lithium Battery YTX14-BS PC545 YTX14L-BS at Motorcycle Products Ltd. This Motobatt MHTX16 Hybrid Lithium Battery is like a mix of old-school lead-acid and high-tech...

www.motorcycleproducts.co.uk

I also noticed a part from the massive weight saving and more room you now have in the battery area that the voltage on the bike sits at 12.7v where as my previously brand new Yuas HP battery (and the original OEM one before that) would drop to 12.3/4 volts within seconds of turning the bike on with nothing turned on.

I'm a happy man and again thank you to Adam for searching this battery out!!

 

[Pukmeister]

The best thing aside from reliable starting is no more big warnings dominating the TFT screen with tales of impending doom, like “SOS service faulty, visit dealer”, “rear brake light not working”, “Key not detected, unable to restart if stopped” and loads of other bollocks it has shown which are all simply triggered due to low voltage during starting with a shit battery. I’ve even had a call from my tracker company to check my bike isn’t being stolen (whilst riding it home a minute after starting it at work, thank heavens for sena comms).

One final issue to resolve is the second years warranty on the battery. You need to register the battery serial number on the “Hendler” website (UK Importers) but my serial number wasn’t recognised so I have emailed them with all the details and currently awaiting confirmation that my new battery is now registered with them.

 

[SBD]

A new and well tuned 1200/1250 engine does not have a starting problem

Mine did. And I’m sure I’m not alone.

It’s now three and a half years old, has had a new alternator under warranty, has had a new 240A CCA Battery not under warranty, and still occasionally fails to start. It always starts when a booster or jump start is attached, so increasing the available power helps, but I don’t know if that’s due to more volts applied, or more current available, or both, of course.

There’s something wrong with some bikes. I guess not enough for BMW to “need” to do something

 

[Bigcats]

Mine did. And I’m sure I’m not alone.

It’s now three and a half years old, has had a new alternator under warranty, has had a new 240A CCA Battery not under warranty, and still occasionally fails to start. It always starts when a booster or jump start is attached, so increasing the available power helps, but I don’t know if that’s due to more volts applied, or more current available, or both, of course.

There’s something wrong with some bikes. I guess not enough for BMW to “need” to do something

Like this, mine was less than 3 years old...full BMW service history

It's absolutely nothing to do with tuning as the ECU will tune the engine from all the data it's getting.

That's the whole point of modern ECUs

Also a bike less than 3 years old shouldn't need tuning so I absolutely agree with SBD on this.

There is something wrong

 

[Pukmeister]

It always starts when a booster or jump start is attached, so increasing the available power helps, but I don’t know if that’s due to more volts applied, or more current available, or both, of course.

That’s the beauty of this Hybrid battery, it’s basically an AGM battery with a Lithium booster pack permanently in parallel.

The Lithium part takes care of the “heavy lifting” during starting like a booster pack does, delivering instant power with minimal volt drop.

The AGM part takes care of the steady load requirements when the alternator output is reduced eg slow traffic riding, lots of accessories in use.

It seems a clever engineering solution.

 

[SBD]

That’s the beauty of this Hybrid battery, it’s basically an AGM battery with a Lithium booster pack permanently in parallel.

The Lithium part takes care of the “heavy lifting” during starting like a booster pack does, delivering instant power with minimal volt drop.

The AGM part takes care of the steady load requirements when the alternator output is reduced eg slow traffic riding, lots of accessories in use.

It seems a clever engineering solution.

Well, maybe.

Or, as Knutk has suggested, maybe adding capacity is masking an existing problem, and/or potentially creating or storing up problems for the future.

It certainly seems to be a useful and effective quick fix. I guess time will tell.


If I get a chance today, I might get the solenoid off, clean the terminals and check there’s no visible tracking.

Does anyone have a wiring diagram that they could share?

I tried to download one but the site was either useless or a scam. The particular point I want to identify is any cable or connection that carries the starter current and the power to the ECU. This includes the battery connections to ground and solenoid, but maybe some others too, such as the alternator.

My hypothesis is that there’s a dirty/poor contact in this circuit which has a measurable resistance. This would “waste” volts (and thus limit the current) when there is a significant current flowing - during starting, and during the first few minutes after starting when the alternator is trying to recharge the battery.

If my suspicion is correct, the ECU might be browning out during starting, and thus refusing to allow the bike to start. It might also explain the “14.4V when riding” but battery not fully charged. And thus the “doesn’t restart when just ridden a couple of miles” scenario which seems quite common amongst those of us that have the issue.

 

[SBD]

I absolutely agree with SBD on this

If not much else!!!

 

[Pukmeister]

There is no solenoid. There’s just the starter relay (which is a moulded component and not user-serviceable).

I’ve replaced my starter relay, it takes five minutes.

The starter uses a sprag clutch or similar inside the engine to disengage. It’s not like an airhead/Hexhead pre-engaged type with a starter solenoid.

I fully agree with your last part re: the ECU “browning out” under low voltage. That’s the exact symptoms I had, a few multiple attempts at restarting my engine from hot soon resulted in no starter motor spin, the ECU would not allow it.

I suspect the root cause is a poor/sticking decompressor mechanism resulting in excess strain on an already undersized standard battery. The extra clout from a lithium booster pack or hybrid battery overcomes this.

 

[SBD]

There is no solenoid. There’s just the starter relay (which is a moulded component and not user-serviceable).

The starter uses a sprag clutch or similar inside the engine to disengage.

Ok, relay then.

On some vehicles, the fat copper bolt/nut that fixes the battery cable to the relay/solenoid also attaches the alternator output and the feed to the fuse box. I’m guessing there’s a similar “single point of failure” hidden somewhere in the wiring. It could be on the return side too, maybe where the battery cable attaches to the frame.

I want to find and clean those connections.

 

[Pukmeister]

It’s a very simple circuit…...

Battery main live feed cable disappears forwards under the tank, I suspect it splits there with a feed to a major power contactor controlled by the keyless module and also a feed cable to the starter relay input terminal under the left side panel.

The output cable from the starter relay goes straight to the starter motor brush pack.

The starter motor casing ground cable returns to the battery negative terminal to complete the circuit and provide an engine casing ground.

I didn’t see where the alternator output attaches to the circuit but I’d suspect it’s under the fuel tank somewhere.

 

[Pukmeister]

FWIW I had some very light oxidation to the starter relay cable eyes. I cleaned them up with a scotch pad, installed the new relay (nyloc nuts) then coated the terminals with Dow Corning electrical insulating grease to prevent further oxidation.

 

[Bigcats]

If not much else!!!

Heh it's only politics!!

 

[SBD]

It’s a very simple circuit…...

Battery main live feed cable disappears forwards under the tank, I suspect it splits there with a feed to a major power contactor controlled by the keyless module and also a feed cable to the starter relay input terminal under the left side panel.

The output cable from the starter relay goes straight to the starter motor brush pack.

The starter motor casing ground cable returns to the battery negative terminal to complete the circuit and provide an engine casing ground.

I didn’t see where the alternator output attaches to the circuit but I’d suspect it’s under the fuel tank somewhere.

I would like to trace that main feed cable, to where it splits, as I think that’s where the problems lie. If it means dismantling the bloody bike, I think I’ll restrict myself to the live & return connections that I can see. A Scotchbright & Vaseline treatment might not help, but for sure it won’t hurt.

 

[NeilCol]

Love reading the fellas with the mechanical knowledge talking over these issues. Makes me realise how completely clueless I am about such matters, I’m a ride it/clean it guy….who doesn’t even really like taking bits off to make the cleaning easier.
Never know whether I should put any grease/locking back in any bolts I take out.

Serviced the old CBR 600 myself, even doing the valve clearances but figured it was low risk in a cheap £1000 bike, quite enjoyed doing it but took forever with zero knowledge and a Haynes manual.

When I got the 1200gs it was modern, expensive and not worth me messing up, and the cost of the current new models has amplified that further. Plus, finding what the torque setting is for tightening is generally hard work to find out!

Maybe when it’s a bit older and I have retired from my current job I might start tinkering and learning a little bit.

 

[Santa-2512]

There’s something wrong with this "xxx" / model / range

I guess not enough for "Insert here" to “need” to do something

Not strictly true,

In my days of working with 4 wheeled stuff, i can definitely say that every warranty claim, dealer part swap , customer complaint, is looked at and dealt with.

Even more so now



If you want to be really worried go and investigate Takata air bags

67 million have been recalled for faults in there manufacture

and they believe a further 11 million are out there !

I told my dealer i had a Takata airbag in my car, they denied it for 5 years until the recall landed on the mat

The problem is Takata stopped keeping records,

In 2017 they went Bankrupt

So whats in the units and where they went is literally a needle in a haystack

when they uncover data that can identify a marque / model, the next batch of recalls goes out

They are still recalling vehicles ! , with the last batch being identified in 2024!

 

[Pukmeister]

As feedback, I’m currently in Luxembourg/Germany and the bike has started reliably every single time, even after accidentally stalling when hot it fires straight back up exactly as hoped for.

I’d say the new Hybrid battery is brilliant.

……..Now if only it would stop raining !


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[NeilCol]

Good to hear…not about the rain..but wife and I are going over in little over a week from Hull to do Germany staying near Koblenz, then into Luxembourg for a night before going off into France for a night and back to UK from dunkirk.

I hope the weather has sorted itself by then