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[pacificcricket]

Reconfiguring all cells into a single string sounds hard.

Not any harder than reconfiguring four 12 volt lead-acid batteries between parallel and series configuration. The only additional consideration is around BMS.

[Doug S]

It would also be possible to have a box to convert DC charge current to 240V AC then run it into the onboard chargers and a bigger charge tank charger. Not as efficient though or cost-effective but possible. The whole setup would just be a DC charge tank in one unit.

Assuming the first thing on the AC charger is a properly sized full-wave bridge, you don't need to convert it to AC. The bridge's purpose is to rectify the AC to a raw DC voltage, which the charging circuitry filters and regulates to the proper DC voltage and current to charge the battery. If you run DC into the bridge, it still comes out rectified, though only two of the four diodes is used, so you may need a higher-rated bridge, but a lot of chargers already have them. IIRC, Brandon has stated that the Diginow charger can run off of AC or DC.

So really all you'd need is the front end to handshake with the DC charging port, to tell it what DC voltage the charger wants to run on. Kinda defeats the purpose of level 3 charging, since the whole idea there is to put the charger off of the vehicle, but it would work.

[minronnee]

Perhaps this bike will be attractive to some buyers, but as a long time Zero DS owner I wouldn't buy one. Wake me up when the battery pack voltage is upped so the bike can do ChaDeMo / CCS without issues.

Well said... in fact after getting my hopes up for this I just may be selling my 2016 DS when the lightning comes out or the Kymco. If I was going to spend over 20k I would buy the Energica just for how fast it charges. my DS 13.0 gets me around to all the places I need and I do like it but after the massive let down on this  new world/industry changing SRF release  I will not waste any more money on zero until charging is faster than 35 min or the bike goes 300 miles on the freeway. I have a feeling this will be my second/last zero.

[togo]

> Assuming the first thing on the AC charger is a properly sized full-wave bridge, you don't need to convert it to AC...

The point of a fast DC charger is for it to match volts and amps and then push current directly, so there's no need for an onboard charger and its limitations, just signaling.  I.e. the charger is in the station, not the vehicle.

That said, I wouldn't be surprised if the Diginow could charge off high DC voltage, I've heard rumors of experiments in that direction...

[pacificcricket]

That said, I wouldn't be surprised if the Diginow could charge off high DC voltage, I've heard rumors of experiments in that direction...

Like it was stated earlier, many switching power supplies will readily operate on DC input within the same voltage range as the intended AC input. The problem is the current will still be limited by the output circuit of such converter, so the only thing hooking up Diginow to a Level3 charger is solving is ability to charge in the absence of Level2 chargers but presence of Level3 ones

[Killroy]

I don't have a lot of confidence that the cooling fins on the battery pack will do much to cool the core of the pack, but why did they not design the fins in the direction of flow when the bike is moving?

See>>>

[pacificcricket]

I don't have a lot of confidence that the cooling fins on the battery pack will do much to cool the core of the pack, but why did they not design the fins in the direction of flow when the bike is moving?

Pack is more likely to heat up more during charge than discharge. I did some number crunching, max continuous discharge given 600A Sevcon could be a bit over 200A spread across multiple strings, so with 4P only some 50A per string (and thus per cell). And that is only "max of continuous", which won't happen when cruising even at 70MPH, only when accelerating to 70MPH. So really position of the fins doesn't matter, as they'll be more helpful when bike is stationary and charging (fast).

[Killroy]

I'm rethinking this now and what are the 3 most important Electric Motorcycle specs?

Range, Recharge time, cost. 

Cost is tricky right now, but I would like to see improvement in Range and Recharge time.  Now they are hinting at >6 kW, but that is only practical if you are Double J charging, which I know a lot of people do with Diginows, but it's not ideal. 

CCS would of been very handy and maybe it would save some weight.  A higher voltage system has efficiency advantages, right?

Range. Wouldn't it be easy for Zero to allow a small bump in the battery box size to allow a ~16.5 kWh standard battery size?

The other improvements are great, but they are lower priority.  Nice to haves: new dash, app, connectivity, ABS and Traction control, heated grips, Cruze control, LED lights, ect

[NEW2elec]

killroy the "fins" are shaped in a way to give a lip to bolt the batteries (looks like two long bricks to me) together and get some frame support.  The material used may be more heat conductive but the over all shape of the fins is more for structure from what I can see.

I see you posted again. OK
Zero has always had a plan to use up all the old batteries before making new ones.  The FX models kept the old bricks long after the S bikes had moved up.  The 2018 S and DS still had the 13kWh batteries and now they all moved up to share the 3.6 brick platform.
The new frame design does seem to be able to modify the size pretty easy and make it wider or longer or deeper to hold new batteries in the future but my guess and only a guess is the 3.6 bricks will run through 2021.  That lets them make some money from the R&D of the 14.4 before moving ahead.  Or until someone else offers a bigger one than Zero.

[Killroy]

I don't have a lot of confidence that the cooling fins on the battery pack will do much to cool the core of the pack, but why did they not design the fins in the direction of flow when the bike is moving?

Pack is more likely to heat up more during charge than discharge. I did some number crunching, max continuous discharge given 600A Sevcon could be a bit over 200A spread across multiple strings, so with 4P only some 50A per string (and thus per cell). And that is only "max of continuous", which won't happen when cruising even at 70MPH, only when accelerating to 70MPH. So really position of the fins doesn't matter, as they'll be more helpful when bike is stationary and charging (fast).

OK, then what is the limiting factor when riding fast? Motor controller?  From Zero presentations on the motor improvements I thought that the Battery, Controller and Motor were optimized to near the thermal limit at similar times.

[ashnazg]

I don't have a lot of confidence that the cooling fins on the battery pack will do much to cool the core of the pack, but why did they not design the fins in the direction of flow when the bike is moving?

Pretty sure I read that the bellypan is now a scoop that channels air toward the battery and motor... thus the air moves upward from the bottom.  That might explain the vertical fins, at least partly.

https://www.zeromotorcycles.com/zero-srf/
Rotate the 360 pic about 45 degrees between front view and a side view... you can see two openings in the front of the pan.

[Richard230]

I don't have a lot of confidence that the cooling fins on the battery pack will do much to cool the core of the pack, but why did they not design the fins in the direction of flow when the bike is moving?

Pack is more likely to heat up more during charge than discharge. I did some number crunching, max continuous discharge given 600A Sevcon could be a bit over 200A spread across multiple strings, so with 4P only some 50A per string (and thus per cell). And that is only "max of continuous", which won't happen when cruising even at 70MPH, only when accelerating to 70MPH. So really position of the fins doesn't matter, as they'll be more helpful when bike is stationary and charging (fast).

OK, then what is the limiting factor when riding fast? Motor controller?  From Zero presentations on the motor improvements I thought that the Battery, Controller and Motor were optimized to near the thermal limit at similar times.

From reading motorcycle magazine road tests of the SR/DR recently, it would seem that the limiting factor for those models is battery heating. The complaint is that when the battery hits around 130 degrees F, everything shuts down, including charging, until the batteries slowly cool off.  Needless to say, the motorcycle testers have not been happy cooling both their heels and the battery packs somewhere in the middle of nowhere.    Apparently, Zero has attempted to address this problem on the SR/F.

I am happy to see the radial fins of the new motor and I agree that they should cool better than the longitudinal fins of the older motor case.  But oddly, I like the looks of the older motor more than the new version.   

[pacificcricket]

OK, then what is the limiting factor when riding fast? Motor controller?  From Zero presentations on the motor improvements I thought that the Battery, Controller and Motor were optimized to near the thermal limit at similar times.

When cruising fast I don't believe anything will be pushed near their limits. Sustained high speed takes a fraction of current spent on acceleration at full throttle. So unless you're repeatedly doing 0-60, you're not pushing the bike to the limit. If you're doing just that, sort of like in a racing setting, then I'm not sure what will reach the limit first without looking at the specs and some testing charts. The thing about Lithium cells though, they often have a lower thermal ceiling for charging than for discharging.

Here is the datasheet for one of the Farasis pouch cells used in previous models : https://evmc2.files.wordpress.com/2013/12/fei-datasheet-imp06160230p25a-pouch-25ah-v5.pdf
There are two thermal ranges specified :

Operating Temp. -20°C to 60°C
Charging Temp. 0°C to 45°C

[ultrarnr]

Battery overheating is a bigger deal for charging than it is for the motor. Last summer I rode my Eva to Charlotte, NC when the temps were in the low 90s. On the second DCFC it started to taper earlier than I had seen it before. When I took off I noticed the battery icon was yellow and it stayed that way for 15-20 minutes of riding but no reduction in power. On the third and last DCFC it started to taper even earlier and the battery icon styed yellow all the way home, about an hour ride. Again, never noticed any decrease in available power.

[Killroy]

OK, then what is the limiting factor when riding fast? Motor controller?  From Zero presentations on the motor improvements I thought that the Battery, Controller and Motor were optimized to near the thermal limit at similar times.

When cruising fast I don't believe anything will be pushed near their limits. Sustained high speed takes a fraction of current spent on acceleration at full throttle. So unless you're repeatedly doing 0-60, you're not pushing the bike to the limit. If you're doing just that, sort of like in a racing setting, then I'm not sure what will reach the limit first without looking at the specs and some testing charts. The thing about Lithium cells though, they often have a lower thermal ceiling for charging than for discharging.

Here is the datasheet for one of the Farasis pouch cells used in previous models : https://evmc2.files.wordpress.com/2013/12/fei-datasheet-imp06160230p25a-pouch-25ah-v5.pdf
There are two thermal ranges specified :

Operating Temp. -20°C to 60°C
Charging Temp. 0°C to 45°C

Sustained highway speed for my 2015 Zero is only 80-85 mph in the summer.  It does have the non IMP motor, so I am not sure if that is the limiting factor, but that is not repeated 0-60, that is just fast cruising.