FAQ - How do I charge my Enertia?

[Brammofan]

From: Charging, Clarified:
It's a bit of a shock, pardon the pun, to title a post "For Enertia Owners" and realize that the intended audience includes someone other than a visionary in Iowa, Jay Leno, and this guy.

Anyway, one of the new owners of an Enertia was having some problems with the charging procedure and was able to get Brammo's Lead Designer, Brian Wismann on the phone.  Brian talked him through the procedure and it probably had to do with the handlebar not being in the lock position.  Brian shared a page from the new version of the owner's manual that had a much clearer step by step procedure for the charging mode.  Here it is, for your edification:

[valeek]

I was watching some YouTube videos and came across a certain competitor's video that stated that their bike could be plugged up for months with zero adverse effects.

I was wondering if the Enertia has a similar BMS that prevents overcharging/heating/etc.

[BrammoBrian]

I was watching some YouTube videos and came across a certain competitor's video that stated that their bike could be plugged up for months with zero adverse effects.

I was wondering if the Enertia has a similar BMS that prevents overcharging/heating/etc.

Valeek,

Thanks for the question. YES! The Enertia has a very sophisticated BMS (Battery Management System) comprised of 6 seperate "slave" microprocessor PC boards that monitor the individual modules as well as "master" PC board that monitors that receives communication from each module and makes system level decisions based on that information.  This master BMS is integrated into our VCU  (Vehicle Control Unit), which takes information from other systems on the bike (motor, motor controller, lighting, dash, etc...) and makes bike level decisions.  For instance, the VCU is what would tell the bike NOT to accelerate when you turn it on if it detects that the throttle is stuck in anything but the 0 (off) condition.  It would also throw the main contactor relay to shut the bike down if it detected a problem with the charger or if you took the batteries down to a critical threshold where damage could be done if you continued to drain them.  Determining the various states of the bike and potential logic scenarios that must be adressed to make the bike both safe and reliable are a strong point of the Brammo design philosophy and one of the many features that seperates our products from our "competitors". 

[BrammoBrian]

Oops... forgot to directly answer your question.  Yes - you can leave the Enertia plugged in for months at a time without adverse effect to the batteries.  The batteries will essentially enter into a "balancing state" after they've reached full charge, in which the actual current draw on the outlet the bike is plugged into is very low (about 40 watts).

[valeek]

Thanks so much for the reply.  And man, that was quite a mouthful, wasn't it? It's great to know that the Enertia is so well built and monitored.  Everyone can rest a little easier because of that.

Now, I have a second question on charging. 

I was stated somewhere (enter correct reference here) that the Enertia needs to be drained a couple of times to correctly establish a stable SOC.  I was wondering if you could expand on that.  Exactly how low should the Enertia get the first couple of times before it's charged?  And how exactly is that best accomplished without getting stranded in the process?

[ebiker]

another question!

is it possible to disconnect the battery and charge it away from the bike?  unfortunately, i live in a condo and don't have separate electrical outlets i can use in the garage to charge.  i love the bike, but would not be able to charge it any other way.

[Phantom]

Exactly how low should the Enertia get the first couple of times before it's charged?  And how exactly is that best accomplished without getting stranded in the process?

I tried to get the batteries really low to condition them. My goal was 10%.


To avoid being stranded, start with a full charge, ride until you are at 50% charge, then ride back the same route.

[Phantom]

is it possible to disconnect the battery and charge it away from the bike?  unfortunately, i live in a condo and don't have separate electrical outlets i can use in the garage to charge.  i love the bike, but would not be able to charge it any other way.

Disconnecting the battery pack does not seem like a practical idea from what I understand. You could charge another battery and go portable battery-to-Enertia battery.

I use my Enertia to commute to work. It is a short enough distance to go from home to work to home without recharging. Can you charge it at work?

[ebiker]

unfortunately i can't charge the battery at work. 

battery to battery seems to be my only option.

thanks!

[ALephart]

The batteries are not part of a modular "pack" and cannot be easily removed for charging. They can be removed for service, but its not something you would want to do on a regular basis.

All the best,
Aaron Lephart

[BrammoBrian]

Not to mention that the complete battery pack weighs about 90 lbs. Try lugging that up the stairs... !

[Brammofan]

After my first ride (which was shorter than I wished, due to the weather in Kansas City yesterday), I pulled into my garage with a state-of-charge (SOC) of 68%.  I started to wonder whether I should charge or not, and decided to ask Brian:

. . . .  I remember you had originally recommended that new bikes be ridden to within 20% of SOC, before recharging, and that this be done about half a dozen times.  (I remember that this was an issue with Schiff's bike during the first days of the shockingbarack trip).  But  then, I recall that Brammo was pre-conditioning the batteries so that new owners could plug in whatever the SOC was.

After yesterday's ride, I'm at about 68%.  Should I go ahead and take it down to 20%, or not worry about it. 

Here's his response:

I can understand your confusion over "conditioning" the batteries.  Our own understanding of the battery system has improved since the first posting went up about this after first customers received their bikes.  The information that's been provided to date is not wrong, it just needs further clarity.
 
Brammo does, in fact, "condition" batteries at the factory, but I still think a conditioning period by the customer is the best way to get the most out of your bike.   It is the discharge (riding) and charge cycles that work to balance the voltage between strong and weak cells and get the pack working as a "team".  I used to believe that it was necessary to take the bike down to below 20% for this conditioning, but we now believe that as long as you take it below 50% SOC (state of charge), you'll be just fine.  I will admit that part of the recommendation of taking the batteries below 20% was to get new customers over the "range anxiety" barrier and get them more comfortable with riding the bike at a lower state of charge.  If you leave your house and ride until you hit 50% or so and then turn around and go back, you'll end up with a pretty good "mental map" of your real riding range.  So... it's not only the batteries we're conditioning here... it's the rider!
 
Also... leaving the bike on the charger as long as you can (overnight) will allow the BMS to work its magic at the end of the charge cycle and begin balancing.  You can check the balance of the cells with the "secret" tank button press (8 seconds while the key is in the ignition in charge mode), where the high and low voltage of the battery stack will be displayed.  You're looking for somewhere around .050 - .070V difference between the two.

So there you have it, the definitive word on conditioning and charging the batteries on a new Enertia.  As I understand it, I need to take at least another 18% off of the current SOC of 68% before I charge it up.  I am debating with myself about going home for a quick ride at lunch. Given the round trip time of 40 minutes in ideal traffic, I might just have to take a bit of leave to fit in a proper ride.    

[Brammofan]

More on the charging/balancing subject:
Out to lunch

Even Brammofan had a bit of difficulty getting the bike to enter charging mode.  I was good to go with the handlebars in the locked position (which seems to be most people's issue), but what I missed was that the key wasn't quite turned all the way to the Park/Charge position.  Not sure why I couldn't feel it click, but once I figured it out, I was golden.

[Brammofan]

I've included a "Charging" section on the Brammoforum Wiki:
Charging
If you're familiar with Wiki markup language (or even if you're not, but want to learn), log on and add/edit to your heart's content.