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[TNCreator]

I will maybe have to do a 400km (250mi) trip each way by hot weather, 32°c (90°F)

I was wondering if limiting the power, for example to 60A instead of 75, would lead to sufficiently less heating to improve the thermal situation on a longer trip.
On one hand I feel like putting less heat in the battery would make the thermal throttle happen later and cool faster when riding.
On the other hand I guess the time lost charging slower just makes the thing balance itself out and the result is the same.

any experience on this ? do I try to manage it or just send it full blast and let it regulate itself ?

[Stonewolf]

If you're doing more than one charge in a day you're better off charging at 65A rather than 75A generally. You might get some benefit from charging at 60A, I found with my battery's anomalous thermal issues that dialling it down further helps give a more predictable charge time but for a healthy battery you should be ok at 65A for two charges unless the air temperature is particularly high.

[szczur333]

in theory yes

but it is pointless to slow down charging first chargng and wait, only for slightly faster 2nd or 3rd charging


I always going at full power at trips, besides at situations when I am stopping for a little longer - then I calculate and reduce amps

PS
I made 600km fun ride at mountains with friend on ICE bike - breaks every 100-120km, 20-23*C ambient - 15-80% charging - always starting with full speeds (battery temp always below 30*C


I charge faster than friend can eat his sandwiches

[Specter]

slowing down maybe 10 amps may help a bit but i don't think it's super major.  once you get on the road again, air flowing past the battery will help cool it down again fairly quick... unless... you are doing 100 mph  pulling 100 amps, then it'll stay hot.

another thing to remember, even with slower charge, breezy cooling etc, the heat inside the battery has to make it's way outside by going thru all the other battery shit, it's not like those inner batteries are right against a cooling fin, if what i understand is correct.  Therefore no matter what you do, there are just limitations on how effective it will be.

aaron

[ElectricRebel]

slowing down maybe 10 amps may help a bit but i don't think it's super major.  once you get on the road again, air flowing past the battery will help cool it down again fairly quick... unless... you are doing 100 mph  pulling 100 amps, then it'll stay hot.

another thing to remember, even with slower charge, breezy cooling etc, the heat inside the battery has to make it's way outside by going thru all the other battery shit, it's not like those inner batteries are right against a cooling fin, if what i understand is correct.  Therefore no matter what you do, there are just limitations on how effective it will be.

aaron

Well, the cells themselves are grouped in 9 "modules" if you can call it so. The only part that would be able to dissipate great amounts of thermal energy would be the right hand side battery cover. That's basically the "short" side the Cells are resting against. So the worst and ineffizient way of dissipating the heat generated, so the battery will warm up. But there's WIP by me and another dude from the nordics regarding this issue😉 Will get a separate post when finished 😉

[ElectricRebel]

I will maybe have to do a 400km (250mi) trip each way by hot weather, 32°c (90°F)

I was wondering if limiting the power, for example to 60A instead of 75, would lead to sufficiently less heating to improve the thermal situation on a longer trip.
On one hand I feel like putting less heat in the battery would make the thermal throttle happen later and cool faster when riding.
On the other hand I guess the time lost charging slower just makes the thing balance itself out and the result is the same.

any experience on this ? do I try to manage it or just send it full blast and let it regulate itself ?

Something I found out in 30°C+ weather
-40/45A: You'll be able to Charge 3-4 Times at that rate continuous
-50/55: Will drop down to ~45A during the second charge
-60A+: Same as 50/55, but your first charge is faster.
-It is also helpful being easy on the throttle and reducing the Regenerative brake, as high levels of regen do heat up the battery as well

I personally do 60A.
Good compromise for first fast charging the first session and heat generated during the second one 😉

[Motoproponent]

Its been my experience that it doesn't make an appreciable difference.

The first charge of a long day is "fast". Subsequent charges are much slower. Like first stop is around 45 minutes to an hour on hot days (about 100°F) . 2nd and 3rd stops are more than an hour.

I don't throttle the charge rate. When I travel (Experia) i shoot for 350 to 400 miles a day. Riding slowly to give more time between charges helps more than limiting charge power. Also taking a long lunch and letting the bike sit in the shade without charging or discharging for 20 minutes can help the charge rate start in the 20s instead of the high teens.

[Specter]

That is one huge thing for your battery temp, the sun.
letting the bike sit in the sun basically puts it into the oven.
im not going to get into a chemistry doctoral here but long story short, that plastic is real good at converting the sunlight into long wave heat... translation the shit gets very nice and toasty under there.

keeping your bike in the shade helps much more than you can imagine, and even when you can't, even a mere throwing a towel over the tank / where gas tank would be / battery area does huge help towards keeping it cool .vs. just letting direct sunlight on the black/grey plastic, cooking everything under it.  the towel absorbs the rays, and any heat conversion gets pooftied in the towel instead of directly under the cover and into the battery compartment / inverter compartment.

even on track days, a simple towel over the cowling while charging or sitting in the sun, would mean the difference between warm to the touch vs, literally it will burn you if you touch it.

Aaron

[ultrarnr]

Aaron,
Completely agree. NC has had temps in the upper 90s the past few days and the battery on my Ribelle is yellow without even leaving the parking lot.

[Dryer667]

I believe Hans did an experiment and posted a video that 50A was the best balance between speed and repeated charging. Its has actually become my default speed for my 20min charge sessions. Ill knock it up higher if I am just doing a quick stop when riding with ICE bikes or something like that.

100% agree on the sun's impact.

[MVetter]

Basically we're all in agreement: We should be sporting dainty little parasols for charge sessions.

[Specter]

maybe hook a portable ac unit to the battery and have an inflatable little garage you can put the bike into while charging.   make sure it has one of those rooster weather vanes on top so you can see the wind direction.

Aaron

[ms_smart]

May be this does not answer the question, but it might be interesting anyway. I have connected a OBD2 dongle to my Experia for a year or so and gained some data I would like to share with you.
First graph is a charging session on DC from 10% to 70%. Ambient temp was 24.8 Celsius. Learning from this graph:

• 10% SOC increase heats up the battery ~2 degrees Celsius
• <= 40 deg Celsius you get full DC speed
• > 40 deg Celsius <= 50 deg Celsius: DC speed throttles down 1KW for each degree
• Although not visible from this chart: > 50 deg Celsius DC charging speed will dramatically throttle down

Second graph is captured while driving the same day.
The blue area in the chart reflects the consumption. Most interesting is the yellow line (battery temp in Celsius).
Learnings from this chart: The battery temp increases while driving. The increase is partly due o increased ambient temp (green line), but as you can see it gets ~10 deg Celsius higher than ambient temp after 220km of riding - this was the time of the charging session. After DC charge the battery temp is 49 degrees, a delta of 23 deg Celsius to ambient temp. The battery temp than decreases while riding to 44 deg Celsius. It looks like it does not decrease further (18 degr above ambient temp).
The last chart is captured while riding at a day with two (short) DC charge stops. For me it is evidend, that the fundamental findings are still true.

This would be my advise if you want to ride long distance:
Keep the battery as hot as possible but below 50 deg C. Reason: The hotter the battery the more it will cool down while driving. Below 50 deg Celsius you still have acceptable charging speed.
Charge DC until charging speed drops to ~16 KW (49 deg C batt temp)
Ride  ~80km and bring down battery temp 5 deg C. Riding further will only decrease SOC, but not significantly battery temp.
This 5 deg delta will allow you to charge up ~25% SOC. If you drive very efficient you can keep running this way.

All data I captured is in Summertime and riding in the mountains with lots of regen.

[DonTom]

I personally do 60A.
Good compromise for first fast charging the first session and heat generated during the second one 😉

Another good reason is to help protect the DCFC fuse located inside the battery pack.  My 90-amp DCFC fuse recently blew inside the battery pack on my 2020 SS9-, which is a big hassle to repair because the battery must be removed from the bike. I used to just let it charge at max., but from now on I will also be setting all my Energicas  for 60 amps.  Not a big noticeable difference in the time it takes to charge but it has to make a nice difference in the battery heat.


-Don-  Reno, NV

[TNCreator]

thanks all for your answers, very interesting.

yesterday I had a good confirmation of the importance of the sun, with the battery going to yellow only by driving after sitting in the direct sunlight by ~35°c with no charging that day, I would not have guessed that was even possible.

so dumb question but wouldn't a simple reflective cover on the exposed parts make a huge difference ? like some space blanket material or even a white fabric sheet that could be lightly sprayed with water for a strong evaporative cooling while riding.