ElectricMotorcycleForum.com
Makes And Models => Energica => Topic started by: MikeL on January 17, 2023, 12:18:21 AM
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According to the Experia manual, you should charge to 100% every 15 days to maintain cell balance. See screen grab below. Usually everyone on here is like 'never charge to 100% unless you have to for a trip' etc right? What do you all think?
Also it seems like cell balancing starts at 98% and only on AC. I always thought cell balancing started earlier on the other bikes.
(https://i.imgur.com/oUxwMYl.jpg)
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Not everyone here…I balance before most rides. I usually don’t charge directly after arrival (when >50%) but do the charging (timed) before departure. In that way the time spent at 100% is limited and cells wear evenly. Also there are no surprises driving in lowish SOC with well balanced batteries.
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I do not understand why the batteries will not balance with a DC charge. In fact, it makes no sense, because even an AC charge is a DC charge to the battery. The only difference is a CCS charge is much faster. Does balancing require a slower charge? And if so, why does my SS9- say to let the balancing finish, right on the screen when charged with CCS when it gets to above 80 SOC?
-Don- Reno, NV
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https://www.batterypowertips.com/active-cell-balancing-basics/
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Excellent general explanation of cell balancing techniques. Thanks. While Energica obviously is not interested in sharing their exact implementation, there seems to be a current limitation in the balancing process, which extends charging time and would possibly violate fast charging protocols. The alternative would be to allow - still active - cell balancing after/without (fast) charging. This would cost some capacity because cells with a higher voltage/soc would have to donate to those with a lower one.
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Excellent general explanation of cell balancing techniques.
Now if it would only explain why the Experia will only balance on an AC input charge.
-Don- Reno, NV
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I do not understand why the batteries will not balance with a DC charge. In fact, it makes no sense, because even an AC charge is a DC charge to the battery. The only difference is a CCS charge is much faster. Does balancing require a slower charge? And if so, why does my SS9- say to let the balancing finish, right on the screen when charged with CCS when it gets to above 80 SOC?
-Don- Reno, NV
Yes, balancing requires a lower charge rate (~4amps as observed) because the cells that reach full capacity will have their charge current bypassed to a shunt load while depleted cells continue to charge. This BMS method of operation can take significant time and isn't practical for L3 charge mode.
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Yes, balancing requires a lower charge rate (~4amps as observed) because the cells that reach full capacity will have their charge current bypassed to a shunt load while depleted cells continue to charge. This BMS method of operation can take significant time and isn't practical for L3 charge mode.
Is this also true on my 2020 SS9-? If so, my screen lies to me during a CCS charge.
-Don- Reno, NV
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If I may add.
Cell balancing typically happens when the battery is almost at full charge. Being this, there should NOT be a heck of a lot of balancing needed if the battery is working correctly. Also, at that SOC, there is not much current needed anymore either, it's pretty much just topping off. Think of when you are topping off your gas tank on your ICE, you are dribbling it it, not full force like an empty tank.
With that, balancing typically only is slinging a few amps at most between cells. Think of a DC fast charger that is able to send 250 KW to a battery pack, and you are telling it, ok now, I need you to send 0.3 kw now... for the next hour.... Most of them probably can not control the current down to 1 amp of flow, 'down that far' reliably anyways. Id also take an edumacated guess and say if I was waiting in line behind someone at the fast charger for 45 minutes for them to squeeze in that last extra KW, I'd be a bit upset, and that's not making the owner of that charger much profit either.
Equalizing is a like smoking meat, it's best done slowly, you know... on an AC charger.
Aaron