Possible Temp Sensor problems?

[Zaphod]

New member here.  Apologies if this maybe has been discussed elsewhere already (I sort of took a look around), but I'm on an accelerated learning curve here and need some information expeditiously:

I took a test ride (for a day, a 24-hour period) yesterday on a 2010 Enertia (with less than a thousand miles on it) that I want to buy, but a couple things concerned me, and I want to know if what I'm seeing is worthy of the worry, or is this just how the bike works:

1) I took the bike out on the freeway right away, and about 8-10 miles into the trip I got a "Thermal Cutback" message on the display, but with no red warning light or decrease in power.  Is that normal?

The ambient temperature was in the mid-fifties (F.), and while I read elsewhere in this forum that riding with full-open throttle for an extended peroiod might bring that message up, ten miles on a cold day doesn't seem like a stress-test to me.


2)  The fan seems to cycle on and off for conditions that (to my uninitiated self) do not seem to warrant it: it was on when I arrived home, it came on during the first charge process (I think about two hours into what was advertised on the panel display as a 2:45 hour-needed charge --shutting down the Charging by the way, in the process: I had to reboot the Charge to finish off the last 20 minutes), plus, the fan came on and off just tooling around the neighborhood: it shut down after a seeming cool-down, and then came back on just a few more blocks... the motor temp (on the LCD display) topping-out at about 160-170 F.  Again, this is a cold day in San Francisco, about 55 degrees F.



I really like this bike.  I really want to buy it.  What I don't want to do is buy a set of problems where I have to immediately buy a new motor because the present one's Temp Sensor is bad.  What this set of circumstances sounds like to me is a faulty Temp Sensor.

Anybody have any thoughts on this?  Thanks in advance.

[protomech]

1. The motor is probably running around 150 - 200 degrees F when under full load. 50 degrees is only a little colder than 80 degrees F to the motor (say motor runs at 180 degrees F - so 130 degree delta vs 100 degree delta). Bottom line is if the thermal system is not designed for continuous full power operation, then it will cut back at some point under full power almost regardless of ambient temperature.

With that said.. maybe Gavin or Brammofan can chip in as to whether this is uncharacteristic for the bike.

2. The fan will come on during charging, but it should not stop the charging process when it does so.

I recall there was one person who had to replace a motor, and I believe it was due to a temp sensor. Maybe wermworks? I would be surprised if this was an issue with the bike you're looking at, but the motors are not very expensive if a problem arises post-warranty.

You might see if the dealer offers any kind of a extended warranty or a short period for a money-back guarantee. If they want to make a sale they hopefully will work with you.

Edit: Here's werm_works post, he did have to replace the motor due to a bad "temp sender" (assume sensor).

[implovator]

Your observations are right inline with my experiences.

Thermal Cutback
It will enter thermal cutback minutes after getting on a highway. It will also enter thermal cutback if you're accelerating too hard too often. Thermal cutback won't necessarily slow you down, but it will hurt your ability to accelerate or maintain speed up hills and into wind. When I get it, I treat it like a slap on the wrist and I hypermile more. Goes away in a minute or so.

Motor Fan
On my 13 mile commute, the motor fan comes on about halfway regardless of ambient temperature. Once the motor fan goes on, it really never stops. My guess is that the motor heats up slowly and doesn't dissipate heat quickly. So the motor fan will be on for a lot of your riding.

Battery Fans
When you charge, after a few minutes, the battery fans come on. At least that's my understanding, for all I know it it might be a charger fan. Regardless, they stay on until the charge hits 99%.

Brammo really engineered the Enertia to be foolproof, and in doing so they erred on the side of caution. Thermal cutback prevents the motor from overheating and ruining the magnets. The battery fans lengthen the pack's lifespan. Their battery leveling does the same. Or take the feature that requires you to flip the kill switch off and back on in the even that you booted it with the kill switch still on. Or even better, try riding down the road and flip the kill switch off and on. It forces you to roll to a complete stop then switch it back off and on.

So yeah, all perfectly normal for this highly-dependable, mild-mannered surface street commuter. And I'll let you in on a secret. The Enertia's still a blast to ride, but the thrill doesn't come from G's pulled during acceleration. It comes from staying off the brake and pulling the G's in corners.

[Zaphod]

hey, thanks, protomech and implovator: that was just the type of insight I was looking for, I appreciate it.

Your replies address most of my concerns; I'll move forward and simply work through the rest, as peculitarities I am not familiar with yet or conditioned to.  (It still is a question to me as to why the charging process fell offline that night, but maybe something got jostled or there's simply something I don't yet understand about the way this machine works.)

But damn that fan is loud.  As some other commentator noted in this forum, it sort of takes away from the generalized notion we all put forward that Electrics Are Quiet.

[BrammoBrian]

I can confirm that you've described normal Enertia behavior.  There is a separate motor fan and charger fans (2 of 'em - they're redundant in case one fails).  We've received many comments on the fan noise, but unfortunately it's the downside of a quiet bike with active air-cooling.  I agree with implovator that the Enertia is a very fun and capable bike despite it's low "on-paper" performance specs. 

I should also mention that doing much more than "exit hopping" on the freeway/expressway is not advisable, as the sustained high speed is pretty tough on the system.  The same could be said for any small displacement gas powered motorcycle as well though...

[BrammoBrian]

BTW - Welcome to the forum and thanks for your interest in a Brammo bike! 

Looking forward to the new ride reports! 

[860]

My personal conclusion was that for my own preferences, I would need an Empulse to feel comfortable on the freeway.  That was my biggest hurdle for getting into EV motorcycles.  Before the Empulse came along, all EV motorcycles all reminded me of these lines from The Matrix:

Trinity: You always told me to stay off the freeway.

Morpheus: Yes, that's true.

Trinity: You said it was suicide.

Morpheus: Then let us hope...that I was wrong.

[Zaphod]

ah.  Interesting.  Well, so... is it your thinking then that a ten-mile trip at, say, 50-55 mph would be  deleterious to the bike?

I wouldn't want to fry or otherwise over-tax it.

[protomech]

It shouldn't hurt the bike. The thermal cutbacks and the fan rampup are there to prevent the bike from damaging itself.

Will it use a ton of battery? Yes. 10 miles @ 50-55 mph will use around 40-50% of the Enertia's capacity.

[BrammoBrian]

ah.  Interesting.  Well, so... is it your thinking then that a ten-mile trip at, say, 50-55 mph would be  deleterious to the bike?

I wouldn't want to fry or otherwise over-tax it.

No, the drive you've described won't over tax the bike. The bike should perform very well at that speed and distance.

[860]

I think your freeway is much different than the ones that run through my city.  Speed limits here are 65 mph on the freeway in most places, with 70-75 being typical traffic speeds.  Nobody goes 50-55 on our freeways.  So what I said about my personal situation wouldn't apply in your situation, because the demands on an EV motorcycle as just so much higher here than where you are.

Here if you want to do 50-55 MPH, we have miles and miles of city streets (not even limited access freeway) that are marked at 45+ MPH, with 50-55 being typical traffic speed.  It's a whole different world here....