BMW R1200RT/R1250RT Forum

[size=14px]I purchased an Optimate 4 BMW and plugged it into my accessory socket on my 2014RT. When I switch it on, it goes through its light sequence and then starts doing its thing. After some time, it shows two greens as expected, but it also shows an orange 0.2 charge continuously. This is different to the Optimate 4 I have on my Harley, which just shows two greens when its done its things. Just trying to work out if there is a fault with the unit or if its a can bus thing and all is actually ok [/size][size=14px]


So my initial enthusiasm for the Optimate maybe waining.

Sounds good to me. Have same charger. The two greens show unit on and in maintenance mode. The orange 0.2 amp is current charge setting. This varies from 0.2 to 0.8 amps. When in maintenance mode it goes through various cycles to keep battery in tip top condition without any degradation. If you can stay awake long enough have a read on the manual. Not easy to understand but does explain the various cycles and lights. Mine is showing the same lights.

Thanks, tried reading the manual. What worrried  me was my other Optimate 4, just sits with two greens for the majority of the time, until it starts doing its thing again. Whereas the new one sits with two greens and always seems to have the 0.2 light flickering

Levisp wrote: Sounds good to me. Have same charger. The two greens show unit on and in maintenance mode. The orange 0.2 amp is current charge setting. This varies from 0.2 to 0.8 amps. When in maintenance mode it goes through various cycles to keep battery in tip top condition without any degradation. If you can stay awake long enough have a read on the manual. Not easy to understand but does explain the various cycles and lights. Mine is showing the same lights.

+1 Had mine since getting the bike & have no problems with it. I plug it in after every trip, I use mine everyday for work, & must say it's keeping it in tip top condition.

Had mine since getting the bike & have no problems with it. I plug it in after every trip, I use mine everyday for work, & must say it's keeping it in tip top condition.


I would suggest that might be a bit of overkill.  I know they can be left for over 3 months and the battery will stay nearly fully charged.  Mine goes on in the winter once a month for a whole day and it's never anything but fully charged. 
I know they say with modern chargers you can safely leave them on forever but at £120.00+ for a replacement battery...........

My 15RT and 13C650 both live on optimate 4's my dealer advised not to use the factory outlet for charging, as there is a software issue with canbus.
To avoid the canbus issues I wired a fused powerlet to both bikes batteries. After the optimate does its thing, left with two green lights.
I now have a charging outlet direct to battery, which can be used for heated gear, air pump and other hi draw items that would cause a canbus fault

I have now spoken to Optimate, all is good, it is behaving as expected. And no issues whatsoever with connecting to the aux socket, that is what the BMW Canbus model is designed for.

Better let them know that the LCs don't  have canbus, its now something called Linbus.

Think its basically the same principle just a new fancy name. Anyway if it works it works 

In fact bit of google research shows, Lin is a less complicated and cheaper alternative to Can


[size=14px]LIN vs. CAN[/size][size=14px][size=14px]CAN is more expensive to implement than LIN. Factors that contribute to the higher cost of CAN include:[/size][size=14px][size=14px][list]
[*]Each node in a CAN network requires a clock generator or crystal
[*]At a silicon level, CAN is more complex to implement
[*]2-wire transmission is used.
[*][/size][size=14px][size=14px]Most importantly, the entire expensive architecture is overkill for applications that demand neither high reliability nor high data rates.[/size][size=14px][size=14px][size=14px]Due to the above drawbacks, the need for LIN networks has increased. The role of the LIN bus is to complement the CAN bus, not replace it. It is an inexpensive serial communications protocol that supports remote and non-critical applications in a car’s network.[/size]
[/list]

Casbar wrote:I have now spoken to Optimate, all is good, it is behaving as expected. And no issues whatsoever with connecting to the aux socket, that is what the BMW Canbus model is designed for.

Optimate also provided this information in an email to Levisp.

"Neither CAN or LIN have any effect on the operation of the battery charger, this is down to the programming of the motorcycle’s battery management system within the central wiring controller. CAN and LIN are both relatively old technologies as they have been in common use for over 15 years. Both are just a means of communicating data between sub-controllers. If there is an instruction within the motorcycles firmware to open the “gates” between the socket and the battery upon receipt of the wake signal at the socket then you will be able to use the charger. Unfortunately if the motorcycles firmware does not have the instruction to do this then there is no way to connect via the socket, even using BMW’s own charger! Worst case scenario you would have to connect your charger direct to the battery."

I agree Lin is a more simple system than Can but not the same.  Switchgear for instance is different for some if the 1600s that have Can and not Lin. I would advise though that if you are using an aftermarket charger you are better going directly to the battery. The BMW charger for instance shuts down when the battery is fully charged. Sounds like the Optimate doesn't. 

T6pilot wrote:I now have a charging outlet direct to battery, which can be used for heated gear, air pump and other hi draw items.

Ditto here, works a treat for charging the battery & using a tyre air compressor.

DaygloDavid wrote: Ditto here, works a treat for charging the battery & using a tyre air compressor.

Popped into the garage last night, and had one solid green and one flashing green only, so looks ok.

Casbar wrote:Popped into the garage last night, and had one solid green and one flashing green only, so looks OK.

Sounds like your battery is now fully charged & the Optimate is doing what is should do, switching between the Voltage Retention Test (Green light #5 flashing) & the Maintenance Charge (Green light #5 steady on).

During the Voltage Retention Test, "Delivery of current to the battery is interrupted for 30 minutes to determine the battery's ability to retain charge. This will prompt the CAN-bus system to disable the 12V outlet within it's own set time limit, disconnecting the battery from the charger. At the conclusion of the test period the program will once again initialize the CAN-bus controlled 12V outlet to measure the battery's voltage and then proceed to MAINTENANCE CHARGE during which the result of the test is displayed."

The Maintenance Charge, "For 30 minutes the circuit offers current to the battery within a safe 13,6V voltage limit whilst the result of the voltage retention test is displayed. The 30 minute float charge maintenance periods follow and alternate with the 30 minute VOLTAGE RETENTION TEST periods until the battery is disconnected."

Based on the above, the Optimate automatically disconnects & reconnects itself to the battery as required.