Battery Query - Does the Can-Bus system cause a battery drain?

[JohnRtl]

I have a new-to-me 2021 RT Limited.
I have an Optimate 4 battery tender which I have used on other bikes - and always put it on charge when it is in the garage.

I have a fused, dual pin connector which is permanently conencted to the battery which I use to plug in the Optimate. When I am riding, it provides the relayed power for various accessories - heated jackets, satnav, on-board video camera, etc. My accessories are therefore completely disconnected when the Optimate is charging.

When fully charged, the Optimate goes through a sequence: Half an hour top-up trickle charge, followed by half an hour monitoring the state of the battery. Repeat forever.
If it detects an issue - eg, the battery is not holding its charge, it indicates this with a green and a yellow light. If all is OK, it just shows a green light.
It checks this a number of cycles before reporting a fault. My battery reports this fault - which means, possibly, an early warning of a battery failure.

However, if I remove the battery and charge it up on the bench, I do not get this fault.
I do not use the can-bus setting in either of these two scenarios. In both cases, the Optimate is connected directly to the battery.

This leads me to think that maybe there is a slight drain on the battery even when everything is turned off.

Question is - is a slight battery drain like this normal for a can-bus system?

 

[BajaRon]

The Spyder will drain your battery. Though I suspicion it is the computer. I've never taken the time to track it down because, in reality, it doesn't really matter where the drain is coming from since it is obviously designed into the vehicle. I seriously doubt there is a reasonable way to get around it.

Let your Spyder sit unattended and it will kill your battery. We sell a lot of batteries at the shop. Most are failed aftermarket or cheap OEM batteries. It really is a crime what passes for a battery these days with some companies.

 

[Snowbelt Spyder]

Hey John. It's not about the CANBUS system, but simply about the parasitic drain from the battery that's supplied to the on-board computers for keep-alive power. The newer the Spyders, the higher this drain is. You've got the best battery maintainer - in my view - and you could be looking at a 5 year old battery. Especially if it is that Chinese battery. Hitachi or something like that. How old is it?

I don't have any idea what you mean by the statement, "I do not use the can-bus setting in either of these two scenarios". There's no such thing. The CANBUS is not a power supply or power distribution circuit for a vehicle. It is a networking communications system for a vehicle. You don't plug things into it, or power things from it. It's how the computers and sensors talk to each other. There are no settings. So, whatever you think you were or weren't doing, that's not really accurate. You don't connect things to the CANBUS.

Depending on the version of it, the Optimate 4 is a 1/1.25 amp unit, which is plenty enough to manage the drain on the battery when the machine is off. For comparison, I have my 2023 on an Optimate 1, which handles the parasitic drain perfectly. As you suspect, your battery is failing the battery health test that the Optimate is performing. So, you may be actually looking at a battery beginning to fail. Or, could there maybe other accessories that were added, and wired in elsewhere by the previous owner that are causing the problem? Your call. But the CANBUS has nothing to do with it.

 

[BajaRon]

Snowbelt has good info and filled in the large gaps I left in my reply. My only addition would be that you need to fully charge the battery with an actual charger before leaving a maintainer like the Optimate 4 to keep it up. They are not designed to bring a low battery back to full charge.

I really like the BatteryMinder charger line. I have several versions. This is the one I recommend for Spyder owners. This is AGM but some will also do Lithium. They are a bit spendy. But for less than the price of one battery, I have brought a few 'Dead' batteries back to life. I was sceptical of the claim when I purchased it. But I've been pleasantly surprised more than once.

There may be comparable chargers for less money. But to test all the chargers out there would take a lifetime. I've now purchased more than 1 of these because they do the job.
BatteryMinder 2012-AGM

 

[JohnRtl]

Hey John. It's not about the CANBUS system, but simply about the parasitic drain from the battery that's supplied to the on-board computers for keep-alive power. The newer the Spyders, the higher this drain is. You've got the best battery maintainer - in my view - and you could be looking at a 5 year old battery. Especially if it is that Chinese battery. Hitachi or something like that. How old is it?

I don't have any idea what you mean by the statement, "I do not use the can-bus setting in either of these two scenarios". There's no such thing. The CANBUS is not a power supply or power distribution circuit for a vehicle. It is a networking communications system for a vehicle. You don't plug things into it, or power things from it. It's how the computers and sensors talk to each other. There are no settings. So, whatever you think you were or weren't doing, that's not really accurate. You don't connect things to the CANBUS.

Depending on the version of it, the Optimate 4 is a 1/1.25 amp unit, which is plenty enough to manage the drain on the battery when the machine is off. For comparison, I have my 2023 on an Optimate 1, which handles the parasitic drain perfectly. As you suspect, your battery is failing the battery health test that the Optimate is performing. So, you may be actually looking at a battery beginning to fail. Or, could there maybe other accessories that were added, and wired in elsewhere by the previous owner that are causing the problem? Your call. But the CANBUS has nothing to do with it.

Thanks for this @Snowbelt Spyder. I understand the basics of a CAN-bus system - that the switches don’t turn on the power to a device, they send signals along the cable which the decoders listen for - ‘is this an instruction for me?’ - and if so, it is the decoders that cause the power to be turned on for that device. Something like that, anyway. So I was wondering if it was the computers and network devices that always required power?

Your answer seems to indicate that this may be the case.

The Yuasa battery is 4 years old, so it is definitely suspect, which is why I took it off to see if the same thing happened on the work bench. It didn’t. But that doesn’t mean that it is 100% ok. There are no previously installed extras - there had been some lights and a console light switch, and a socket connected direct to the battery - I guess for charging. I found some crudely snipped off cabling which I regarded as a potential hazard, and I removed all of that.

The ‘CAN-bus Mode’ setting is on the optimate. You short the terminal crocodile clips for a few seconds when you turn on the mains power feed, and it changes mode. I believe that the CAN-bus Mode doesn’t perform that hourly cycle check, and it fools the CAN-bus system into keeping the system active - presumably for vehicles that have a socket which is controlled by the CAN-bus system. I don’t know about that. But if it doesn’t perform the half hour on, half hour off check, then it isn’t going to detect any loss of capacity.

Really, I need to know how long I can leave the trike without a charger and still have it start a couple of days later? That’s an easy check to carry out. I wondered if the Spyder had a natural requirement for continuous power when turned off. The optimate would detect that.

But a new battery is definitely worth investing in.

Many thanks for your comment - that is reassuring.

 

[Mikey]

Load testing your battery would be the first thing I would do then you know for sure what you have there! To answer your other question about how long you can go without being on the charger, I never have mine on a charger all summer long, the only time it see's a charger/maintainer is in the winter when it's under its cover! Load test is your friend!! It's worked for me for years

 

[Little Blue]

Well here in Indiana USA, I can leave my battery off the charger/maintener all of the riding season. The battery has always started my Spyder. I only connect the charger during the storage time when I don't Ryde.

Maybe in the UK the temperatures and humidity are a factor.
How often do you Ryde?
How long do you Ryde?

Just trying to give you some ideas.

 

[Snowbelt Spyder]

Oooohhhh. You were talking about the CANBUS mode on the Optimate. True. That mode is not applicable for the Spyder. Just the opposite. You’ll WANT the Optimate to go into desulfation mode to help recover the battery if it can be. Otherwise, new battery time.

Taking a quick look at my 2023 wiring diagram - and yours should be similar if not the same - the cluster, audio amp, and VCM are just a few of the components that have un-switched power all the time. No time to trace them all but you get the idea.

 

[JohnRtl]

With my previous ST1300(s) - when riding the bike regularly, I wouldn't bother hooking it up to the Optimate. Over winter (I don't know when I became a fair weather rider - I used to be out in all weathers) - It would be connected as a matter of course. Winter killed the batteries - on my previous ST1100s which I rode all through winter to commute - they would last about 4 years before struggling the morning after the first frosts - and I'd replace with new immediately that happened. Since then I've had the optimate and I've switched them after much longer than that as a precaution - the longest was 7 years - but with a long tour coming up, I wasn't going to push my luck to 8!

I'll get a new replacement Yuasa - the cost of a brand new battery is more than worth the worry of being stranded.

There is a massive unknown for me with this tryke. It's new to me, 8000 miles, 4 years old. I don't know how well it has been looked after. It looks good, but there is a clue in the disgusting colour of the brake fluid - which as far as I can tell from the service records, has never been renewed. Tested, but not renewed. I did all of my own servicing of the Pan Europeans and know this is red flag.

So far I have done only 50 miles on it. Still trying to get rid of the 'reflex countersteer' - but it has been wet and / or icy since I bought it.