Hi there! I bought a Desmo late last year, something of an all time ambition, and it's getting close to ride out weather here. I will never ever tire of looking at it and look forward to really getting to grips with it. Feel very fortunate. I fitted a Lithium battery to it before as it still had the old original in it which was failing to hold charge anymore, only to come back only a few days later and find the battery absolutely dead - and not even recognisable by any charging device. After puzzling around we assumed a faulty unit and bought a replacement, but after a short ride and sitting, it wouldn't start. Attempting to engage first causing some rapid flashing on the dash, and I couldn't get a neutral light. I've got the bike back on the trickle charger - and thankfully it seems to be charging, so this battery isn't total toast. Just looking for any ideas as to what could be causing such a rapid drain / odd behaviour? J
IMO before AC comments, I do not believe that a Litium battery is suitable for a pre MOSFET regulator/rectifier system especially as I suspect it’s fubarred. Seen it happen before with a standard battery that caught fire. Andy
Has anyone got the circuit diagram for the D16.. Was standard equipment a Lithium battery? Have a quick look on here under battery and Lithium for the various threads as I think all bases have been exhausted.
A short circuit would hopefully cause a fuse to blow... or the circuit is designed badly. Is something keeping the bikes electrics awake, alarm, racing timer or GPS tracker? It should be easy to measure the quiescent current, should be under 5-10mA.
In that case then don't fit a Lithium battery.... the bike's charging circuit isn't designed to meet the unique requirements of that brilliant and wonderful technology. Quick tips. Lithium batteries can "go to sleep", normally a few quick jabs of some current draw wakes them up.... try the hooter/horn or indicators or rear light.... wait 20 secs and then again... within a minute it should be awake. They are sensitive to temperature especially cold when charging / discharging.
Many thanks everyone for getting back tonne. The bike has a tracker fitted somewhere, and an HM quickshifter (very fun but very not subtle). Someone else had suggested the reg/rec might be toast - maybe that's the issue. I'll grab multimeter and check draw when it's off. Regarding lithium - does anyone have experience using a lithium battery in a desmo? Seems odd to me they would be widely available if totally inappropriate.
You can buy guns and drugs quite easily in West London, but neither are a good idea, combined even worse... Same with batteries.
Right so I've found and ordered an appropriate MOSFAT reg/rec replacement kit, and removed the suspect OEM one. Getting the airbox off to get it out wasn't my favourite... I'll use the existing left hand fairing bracket to mount the replacement further from the hot engine also, have seen it done effectively. Hopefully this supplies a higher, less fluctuating voltage and takes proper care of the lithium battery.
Which one did you order as the UK manufacturer of these Reg/Recs states: Do not use with Lithium Batteries...
Here's a genuine Shindengen MOSFET reg/rec which some other Desmo owners have fitted with success - https://www.ebay.co.uk/itm/380704480069 2 years no issues and updated architecture to deal with Lithium charging as I understand. From testing and reading, the stock reg/rec runs 13.4 - 13.8v volts when riding which is too low or too inconsistent a voltage to maintain a Lithium battery...but aside from that it seems my stock reg/rec was up to other nonsense which damaged the first battery I put in there.
Jokes aside, with an updated mosfet what's to fear here? Seeing as the original unit caused so many issues / warranty replacements across multiple ducati bikes I'm expecting a safer-than-stock result.
Jokes aside. The issue is heat sinking. I'm not sure where the regulator sits on your bike.... Fitting a lithium battery will cause it to run hotter from time to time. Some lithium batteries have current management circuits built in that negates this. I'm of the school if it isn't broken don't fix it and if I need to loose that much weight off the bike I'll cross Chocolate hobnobs* off the shopping list for a month. *The currency of most of the worlds corruption.
*Savaged half a pack of girlfriend's chocolate digestives and fell asleep infront of Moto 3 last night...might struggle with the diet idea Both the mosfet reg/rec and the new battery have the newer safeguards in for heat so I should be good - here's the placement I plan to use
Looks like it will have good airflow. Perhaps someone who has better knowledge of this machine could confirm. .. but my OCD will NEVER forgive the different mounting bolts.... I really loose my shit when I work on bikes (or any machine) where different fixings are used for no good reason.
As an update - here's the new MOSFET shindengen reg/rec fitted, relocated from under airbox/on top of cylinder head to front fairing. other units are velcroed in place, and the reg sits on one bolt which previously held a bracket for the fusebox. All fits without touching. Wiring was fairly straightforward - still a little cable tie work to do. So far so good. My first Lithium battery could've just been a dud, but I didn't want to risk killing more if it wasn't - so now I have a modern reg/rec. Worth saying Im not sure my bike had the original reg/rec on it anyway as the connectors looked different (and grubby) - and the loom has been cut into to fit the quickshifter.
