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[Squelch]

Greetings,

I hope I'm not being a bother with some of these questions, but this seems to be the one and only place to find good answers!

I am heading out of town for a few days and won't be riding the bike. I rode it a lot today and got it down to 20%. It's currently plugged in but it won't finish charging before I leave tomorrow morning. Is it better for me to let it finish charging while I'm gone and stay plugged in, or should I unplug it and finish charging it when I get home a few days later?

Probably a dumb question, but since this is a brand-new $20K+ piece of equipment I want to make sure I do anything to jeopardize the battery. Thanks for your help.

[ultrarnr]

The charger will turn off once charging is complete. I charge mine everyday after I get home, unplug the next morning when ready for the commute.

[PWM]

Good question.

Charge it to 80% and be assured it will have plenty of charge when you return - never top it off 100% unless you intend to ride it and pay attention to the 2-week balancing interval - work that into your routine and you will be golden.

[MVetter]

You should also look into LPR (Long Period Rest) mode for longer storage. But yes PWM is correct to set it no higher than 80% for the time being.

[Squelch]

Good question.

Charge it to 80% and be assured it will have plenty of charge when you return - never top it off 100% unless you intend to ride it and pay attention to the 2-week balancing interval - work that into your routine and you will be golden.

I know that with LiPo batteries it's bad to let them sit at full charge - is this why you suggest not topping off? That's why I asked the question in the first place because I know with the LiPo batteries that I have for various RC vehicles I have to discharge them if I'm not using them for a while.

I see the manual says "Charge the batteries of the motorcycle to 100% at least once every 15 days to balance the cells making up the battery pack correctly." (page 101) Is this what you mean by the 2-week balancing interval? The manual also says "Once the battery charging cycle has started, do not disconnect the plug until it is complete." (page 102)

[DonTom]

Greetings,

I hope I'm not being a bother with some of these questions, but this seems to be the one and only place to find good answers!

I am heading out of town for a few days and won't be riding the bike. I rode it a lot today and got it down to 20%. It's currently plugged in but it won't finish charging before I leave tomorrow morning. Is it better for me to let it finish charging while I'm gone and stay plugged in, or should I unplug it and finish charging it when I get home a few days later?

Probably a dumb question, but since this is a brand-new $20K+ piece of equipment I want to make sure I do anything to jeopardize the battery. Thanks for your help.

Use the LPR mode and forget about it. You can then leave it plugged in forever and a day, or just for overnight.


I often put mine in the LPR mode just for a few days. It will charge automatically then to the best spot the battery likes for storage. It can be used for short storage as well as for long.


20% is a good spot to use the LPR mode. You do NOT want to start the LPR with the battery at a higher charge than the LPR mode will leave it at.


IIRC, the LPR mode will make sure the battery is charged to just above 80% SOC and shut off. If the battery self discharges, the LPR mode will put it right back to that just above 80% SOC. 


You cannot overuse the LPR mode if you try.


-Don-  Reno, NV

[DonTom]

I see the manual says "Charge the batteries of the motorcycle to 100% at least once every 15 days to balance the cells making up the battery pack correctly." (page 101) Is this what you mean by the 2-week balancing interval? The manual also says "Once the battery charging cycle has started, do not disconnect the plug until it is complete." (page 102)

Don't worry about disconnecting when it says not to. I assumed that was BS, so I asked the same question here and the Energica Service Manager kinda  said to ignore that message--at least most of the time.


Use the LPR mode and only  fully charge (won't take long) the next time you want to ride by turning off the LPR mode.  That will balance the cells and you will start with a full charge.


FWIW, I most often disconnect during that message that says to not disconnect, especially on DC fast charge. And especially on DC chargers where I must pay for the time parked. As soon as the rate falls much below 10 KW, I am usually disconnected. I will get my full charge (and cell balance) when I get home with L2 charging.


The only time I let it charge to full is when I am home and expect to use the bike soon, or if I could need it for the extra range when it's a ways between CCS charge stations .  That will NOT happen on I-80 in CA, but can happen many other places.


I find it works out fairly well for me to get my cell balancing just from my normal riding. Once in a while I let it charge to full because of need, as I have the smaller battery.


It's best for the battery to not charge to full too often, regardless of that message, that IMO, they should change the wording of, or perhaps not have it at all.


I have noticed the time left to charge is NOT shown when that message comes on, which I would rather have displayed.


-Don- Reno, NV

[HoodRichOG]

So what's the actual benefit of balancing the cells to 100% that often and why is it a big deal if they aren't perfectly balanced? Doesn't charging to 100% introduce degradation, or is there a buffer left when the battery is fully charged?

Energica uses NMC batteries, right? So unlike LFP charging them to 100% damages them, no?

[DonTom]

So what's the actual benefit of balancing the cells to 100% that often and why is it a big deal if they aren't perfectly balanced?

Your range is effected by the lowest voltage cells in the pack. You want them all to be charged equally so there are none  that are  lower than the norm fully charged cell.

Doesn't charging to 100% introduce degradation, or is there a buffer left when the battery is fully charged?

You don't want to charge to full every time, just once in a while to help with the cell balancing.  Anyway, that's the way I have been doing it.

-Don-  Reno, NV

[Sklith]

Charging it to full is fine as long as you intend to ride it within a few hours but I would never make a habit of always charging to full. I use LPR mode to charge my bike since it maintains the State of Charge at 86% forever. I still do the cell balancing at the recommended interval which is 10 cycles I believe.

It's best to start the balancing with as close to 0% SoC as you're comfortable with.

[Richard230]

Some years ago I spoke with a fellow who had converted his ICE car into an EV at an electric vehicle event. He swore that the best way to balance battery cells was what he called "bottom balancing" when they were almost completely discharged, instead of balancing them when they are fully charged. It made a certain amount of sense to me, but I can't recall ever hearing that recommendation since then. 

[ultrarnr]

I think there is a difference between what the BMS tells you is 100% and what the true 100% of the cells are. Like many have said here you shouldn't charge to 100% at the risk of damaging the cells. But I doubt you can do that because of the BMS. Just like you can't fully discharge the battery, you can only go until the BMS says there is nothing left. The only exception to that is the military version of the Zero which has a special switch to access the rest of the battery that the BMS won't let you touch. Bottom line is 0-100% based on the BMS (and displayed on the dash)  may be 15-90% of what the cells can manage. Haven't seen any exact numbers on the Energica's cells though.

[Squelch]

Ok, from now on I'll just put it into LPR mode most of the time, and every ten or twelve charges I'll crank it up to 100%. That's fine, especially because there may be weeks where I can only ride it two or three times in the week, and times I travel and can't ride for a week, etc. I've been charging it to full each time due to the wording in the manual (and on the bike itself) that says not to disconnect the charging cable until it's complete.

I guess I would equate it to my laptop, which I put into Battery Saver mode when it's going to be plugged in at my desk for a long period of time. If that's an accurate equivalent it makes sense to me, and helps me understand LPR.

Thanks for all the thoughtful and helpful answers!

[PWM]

So what's the actual benefit of balancing the cells to 100% that often and why is it a big deal if they aren't perfectly balanced? Doesn't charging to 100% introduce degradation, or is there a buffer left when the battery is fully charged?

Energica uses NMC batteries, right? So unlike LFP charging them to 100% damages them, no?

Every pack will have a weak cell or sister of cells regardless at attention to grading where cells of matched internal resistance comprise a pack when they are born...balancing is important to carry the weak sister for the life of the pack.

The weak sister will always raise her hand first and say, I'm full @ 100 SOC so she gets constant voltage applied by means of a current shunt meanwhile healthier cells are allowed to catch up so the system can finally complete the charge cycle and calibrate to 100% - this is top-side balancing.

What happens when one doesn't balance is the disparity between the weakest and the strongest cells grows and the system gets out of calibration, so you may see 30% SOC displayed but really a couple cells are now at their low-voltage cut-off limit which the system may or may not react to...akin to whipping that weak sister cell for being weak...don't do it.

BTW - balancing, from observation on a single bike, starts at 98% and charge tapers to 4-amps because the capacity to shunt is the limiting factor - the more out of balance the longer that 2% takes to complete the charge session.  Execute on a routine balance interval and the balance-time will repeat.  Again, not certain how the system reacts to a low limit condition but that's where the damage is truly done, not at 100%.