Electric Bikes - My first ebike -Schwinn Foldable AL1020

Recently bought a new Schwinn foldable AL 1020 from CT. This e-bike could do a range of 40 km with partial pedalling. The max speed on flat without pedalling is about 20 km/h. This bike seems to be well-built but a bit on the heavy side althought the frame is of 6061 Aluminum. It weights 60 lb with an 24V 12Ah SLA battery pack and 40 lb without battery.
There is no gear-change for pedalling. So it is difficult to pedal to assist the motor when the speed is over 20 km/h.

I have another MTB bike (not e-bike) with 7005 Aluminum frame with 21 gears. I could pedal it faster than the e-bike on flat.

What is the difference between 6061 and 7005 aluminum?

Hi,

I too have had the AL1020 for about 4 weeks and am enjoying the bike. I am a 60 year old retiree and have to ease into any physical workout.
I was getting up to 24 km/hr on perfectly flat with absolutely no wind. Just this morning I added an additional 6 volt 12ah battery in series and got a bit of a performance boost. I now get around 30 km/hr on flat. Before the extra battery the motor would sort of give up at a certain speed. Now it seems to want to keep pushing beyond the original rpm. I find the biggest difference in the hill climbing though. I can now climb small inclines with no assist at a decent clip.
Although I still have to test it out I am quite happy with the results. I don't notice any big increase in heat either on the hub or the controller. They seem to be about "lukewarm" after climbing a medium hill.
I am still in the testing stage but I can post a picture if you want.

7005 aluminum is stronger or lighter, and has longer life.

Hi,

Just this morning I added an additional 6 volt 12ah battery in series and got a bit of a performance boost. I now get around 30 km/hr on flat.
I am still in the testing stage but I can post a picture if you want.

Hi,
Glad to hear your test result and would like to see your picture if available.

Recently I opened the controller and noted the 3 big capacitors are 100uF 100V. Wonder if the controller could work at 36V?
If it could work at 36V, the ebike will have a much better torque for slope and speed.
Is it wise to do such a test?

Check the part numbers on the MOSFETs. Chances are it would work fine at 36V. In fact if the MOSFETs are 55V, you could run 4 SLA's in series as long as the other components are ok for 48V.

My local Canadian Tire just got that model in recently, the the display unit seemed to be fully charged. I took it for a few wheelies down the bike aisle, and it could definitely use more torque and speed :)

Check the part numbers on the MOSFETs. Chances are it would work fine at 36V. In fact if the MOSFETs are 55V, you could run 4 SLA's in series as long as the other components are ok for 48V.

My local Canadian Tire just got that model in recently, the the display unit seemed to be fully charged. I took it for a few wheelies down the bike aisle, and it could definitely use more torque and speed :)

Unfornately the circuit board is potted to the inside of the housing. The housing is used as an heat-sink for the 6 FETs. It is impossible to see the marking on the FETs unless the potting epoxy is removed.

Is there anyway to remove the epoxy without destroying the circuit board?

Data on the controller:
Ananda Drive Technologies Co Lld of Shanghai, China
Model No: 2415DLC-11Z0 / N12C
Date of Manu: 2006-11-29

It seems to be well built.

Any chance to obtain more details or circuit diagram for this controller?

Could an higher-powered controller (say 36V 20A) used for upgrading?

Sorry I took so long to respond. I did some further work on the bike today and I also had to figure out how to host the photos.
My personal opinion is that the controller may take the extra voltage. The controller has some sort of cast aluminum housing. It sits inside an aluminum box which is welded to an aluminum frame - almost a perfect heatsink.
The motor though may be questionable. It is quite small and I wonder if the small amount of heat on the housing is any indication of the heat on the windings. I don't know and at this point I'm too chicken to try.
Here goes with the photos. The first shows my initial temporary setup. The next shows my semi-permanent setup (I'm still not happy with it). Notice how I left room for another 6 volt battery.

http://users.vianet.ca/pdonato/bike1.JPG

http://users.vianet.ca/pdonato/Bike2.JPG

For 24V, the max speed at no-load is 30km/h.
The speed is measured by a digital speedometer via the magnet/speed sensor.
The magnet/sensor is installed at the rear wheel.
The digital speedometer is mounted on the right-hand side of the handle bar.

My e-bike on the stand for no-load test.

The hub motor is a brushless motor with an internal fixed gear.
I am confident that the motor should be able to stand 36V with no problem.
Only thing to be concerned is the controller.

From no-load test on 24V supply, the max speed is 30km/h.
What will be the max speed on flat?
I think that it should be about 24 km/h by taking 80% of that of no-load. (To be verified by to-morrow).

If the 36V supply could be used,
then the max speed would be 45 km/h at no-load and 36km/h on flat.

I think your numbers on the speeds are correct. I also take back what I said about the motor being the weakest link. The controller box (outer one) does heat up slightly when I climb a lot of hills and is not welded to the frame but bolted on. If we can find a way of keeping it cool perhaps with external heatsinks and assuming the heat transfer between the actual controller box and it's external housing is good then 36 volts won't be an issue.
Even as it is now it may work alright on 36Volts.

Anyway let me know what you find out.

Thanks for the info.

Some observerations as learnt from other typical BLDC controllers:

1) The control supply voltages are typically 12Vdc and 5Vdc which are stepped down from the battery voltage by ICs. These regulated-ICs should not be a problem when battery voltage increases from 24V to 36V.
2) There is a max current limiting circuit. I think that it is 15A for our controller because Schwinn uses 24V 15A controller for a smaller size (physically) BLDC motor on IZIP ebike.
3) For the same power output, the battery current should be lower if the the battery voltage is higher. So the temp of controller would be lower at the same speed/power. But it would be almost the same at its max load since the battery current is limited at the same value. So the heating of the controller should not be a problem.
4) The 100V 100uF capacitors should not be a problem when working at 36V.
5) Unable to know the voltage rating of the FETs !!????. If they are 55V or higher as Lowell said, then they should be no problem for 36V.
6) The main risk is to replace all these FETs (or an upgraded controller) if they do fail at 36V battery. ???? !!!!.

Question: To risk or not?

Question: To risk or not?

Where would we be had we not taken risks?

Hiding in the trees and eating nuts and leaves probably.

The hub motor is a brushless motor with an internal fixed gear.
I am confident that the motor should be able to stand 36V with no problem.
Only thing to be concerned is the controller.

From no-load test on 24V supply, the max speed is 30km/h.
What will be the max speed on flat?
I think that it should be about 24 km/h by taking 80% of that of no-load. (To be verified by to-morrow).

If the 36V supply could be used,
then the max speed would be 45 km/h at no-load and 36km/h on flat.

I road tested my ebike today on flat by riding both direction on the same road with full throttle and non-pedalling.
The max speed towards North was 27 km/h and towards South was 25 km/h.
Thus the average on flat is approximatly 26 km/h which is about 85% of the no-load speed.
So my prediction is quite close.

In my opinion, 25 km/h is a bit too low. I would like if it could be 30-35 km/h on flat and it is difficult assist to pedal if the speed is above 20 km/h because it has a single-speed pedalling.
That is why I try to find an way improve it.
36 V battery supply would be the suitable soluttion if the stock controller could stand.

Where would we be had we not taken risks?

Hiding in the trees and eating nuts and leaves probably.

What's the matter with eating nuts and leaves, other when the twigs stick in your teeth?

My tree house is very comfey except there's nowhere to plug in the battery charger.

Recently bought a new Schwinn foldable AL 1020 from CT. This e-bike could do a range of 40 km with partial pedalling. The max speed on flat without pedalling is about 20 km/h. This bike seems to be well-built but a bit on the heavy side althought the frame is of 6061 Aluminum. It weights 60 lb with an 24V 12Ah SLA battery pack and 40 lb without battery.
There is no gear-change for pedalling. So it is difficult to pedal to assist the motor when the speed is over 20 km/h.

I have another MTB bike (not e-bike) with 7005 Aluminum frame with 21 gears. I could pedal it faster than the e-bike on flat.

What is the difference between 6061 and 7005 aluminum?

7005 is the strongest aluminum-it is a high silicon alloy. It is unweldable, but brazable. Usually lug assembly of the frame is used in view of the non-weldability, but there has been an increase in brazing on mountain bikes with this material lately.
6061 is the strongest weldable aluminun alloy.

If your folder were made of 7005, it would be between 1 and 2 lbs lighter than 6061 construction. Most of the added weight is due you batteries and motor.

hey i just saw your video ziping at home depot parking lot. LOL looks so much fun. i live in Vancouver, do you think i can take a look at your bike? you can do the driving and i'll watch. =) im thinking of getting one for short trips around vancity or driving around car show. hehee.

7005 is the strongest aluminum-it is a high silicon alloy. It is unweldable, but brazable. Usually lug assembly of the frame is used in view of the non-weldability, but there has been an increase in brazing on mountain bikes with this material lately.
6061 is the strongest weldable aluminun alloy.

If your folder were made of 7005, it would be between 1 and 2 lbs lighter than 6061 construction. Most of the added weight is due you batteries and motor.

Thanks for the info about 7005 and 6061 aluminum.
I could see a lot of welding in the 6061 frame.

The battery pack weights 20 lbs.
The motor could weight about 6-7 lb.
The bike weights 60 lbs with battery and motor.
The weight of the bike would be about 33 lbs if the battery and motor were removed.

The stock controller was tested at 36 V battery voltage:

No-load test results on AL1020

A)Using 24 V 12 Ah SLA Battery

1) Quiescent Current = 0.06A

2) Max Throttle
Max No-load Speed = 30.7 km/h
Current = 1.22 A
Then input power = 24X1.22 = 29.3 W

B) Using 36 V supply ( 24V 12Ah + 12V 14Ah)
3) Quiescent Current = 0.07 A

4) Max Throttle
Max No-load Speed = 45.7 km/h
Current = 1.60A
Then input power = 36X1.60= 57.6 W

5) Partial Throttle at Speed = 30.7 km/h
Current = 0.95A
Then input power = 36X0.95= 34.2 W

Comments:
1) The 24V stock controller was used for both 24V and 36V test.
2) Quiesent current is only increased slightly from 0.06 to 0.07A.
3) Max no-load speed is approximately proportional to the battery voltage.
4) For the same speed, current for 36V battery is lower. But the input power in higher. This means the heating of the FET would not be a problem.
5) It seems that the stock controller could work at 36V. The 3 big capacitors are rated at 100V 100uF while the voltage ratings of the FETs are unknown because they are potted inside the casing.

Road test with 36 V will be coming soon.

Excellent tests!!
If you do a road test do some uphill @WOT and see if there is any significent heating of the controller or the hub. I am looking forward to your results.

hey i just saw your video ziping at home depot parking lot. LOL looks so much fun. i live in Vancouver, do you think i can take a look at your bike? you can do the driving and i'll watch. =) im thinking of getting one for short trips around vancity or driving around car show. hehee.

PM me your #, and we can meet at the www.ebikes.ca store at 30th and Main st. After trying out a few small tire bikes, and doing some wheelies on the folder in the aisles of Canadian Tire :) I've just changed over to a 20" rear wheel.

The stock controller was tested at 36 V battery voltage:

No-load test results on AL1020

A)Using 24 V 12 Ah SLA Battery

1) Quiescent Current = 0.06A

2) Max Throttle
Max No-load Speed = 30.7 km/h
Current = 1.22 A
Then input power = 24X1.22 = 29.3 W

B) Using 36 V supply ( 24V 12Ah + 12V 14Ah)
3) Quiescent Current = 0.07 A

4) Max Throttle
Max No-load Speed = 45.7 km/h
Current = 1.60A
Then input power = 36X1.60= 57.6 W

5) Partial Throttle at Speed = 30.7 km/h
Current = 0.95A
Then input power = 36X0.95= 34.2 W

Comments:
1) The 24V stock controller was used for both 24V and 36V test.
2) Quiesent current is only increased slightly from 0.06 to 0.07A.
3) Max no-load speed is approximately proportional to the battery voltage.
4) For the same speed, current for 36V battery is lower. But the input power in higher. This means the heating of the FET would not be a problem.
5) It seems that the stock controller could work at 36V. The 3 big capacitors are rated at 100V 100uF while the voltage ratings of the FETs are unknown because they are potted inside the casing.

Road test with 36 V will be coming soon.

The photos of the test are:

The 36 V battery = 24V 12Ah Stock Battery + 12V 14Ah Jump Start Battery

Road test this morning ( Thursday 2007/07/26)

Place: Vancouver BC
Temp = 19 deg C
Weather = Excellent

A) 24 V battery
1)Max speed at flat = 25 km/h
Current = 6A to 9A
2) Slight Slope speed = 19 km/h
Current = 13 to 14 A
3) Max current is limitd by controller to 14.8A
Then max input power = 24X14.8= 355 W

B) 36 V battery
1) Max speed at flat = 35 km/h
2) Slight Slope speed = 25 km/h
3 Max current is also limited by controller to 14.8A
Then max input power is limited to 36X 14.8 = 532 W
5) The testing time = 75 min
6) Average Speed about 19.8 km/h
7) Distance travelled = 25km
The 36 battery are all "EMPTY" with 11.93 V, 11.99V and 12.0V at the end of the road test.
9) Pedalling was only used to assist starting and could not be used at all if the speed was over 20 km/h.
10) Both controller and hub motor were only luke-warm.



Comments:
1) The ride using 36V was much enjoyable.
2) There was no heat problem for controller and motor.
3) Higher speed and torque.
4) If the stock controller does fail, wll ungrade it to 36V 20A one.
5) Will take the risk to use the 36 V version from now on

This is great. I now have the green light to add another 6v battery to my setup.
The problem is I already have a transformer set up which charges my present batteries at about 3 amps and trails off to less than 100ma when the batteries are fully charged. I would have to set up another charger as I prefer to charge all the batteries at once and at the same charge rate.

I do agree with you that the bike is much nicer to drive with that bit of extra power.

My modified 36V version.
Now it would weigh 10 lb more due to tha added battery in the red bag.

I've always wondered, what made you decide to get a foldable electric (as opposed to a standard one)? I always thought that a foldable electric would be great, simply because in some situations you don't want to lock it up outside and you could take it on a train with you or something.

I've always wondered, what made you decide to get a foldable electric (as opposed to a standard one)? I always thought that a foldable electric would be great, simply because in some situations you don't want to lock it up outside and you could take it on a train with you or something.

Because it could be put in the trunk of a car.

I've always wondered, what made you decide to get a foldable electric (as opposed to a standard one)? I always thought that a foldable electric would be great, simply because in some situations you don't want to lock it up outside and you could take it on a train with you or something.

Let me add my 2 cents worth here. Besides the folding feature of this bike I like the construction quality. It appears to be made of a thick light aluminum alloy, much lighter than it's Izip big brother. For $599 Cdn it's a great "bang for the buck".
The 13 inch tires make it a bit more unstable (when you hit holes) but on the other hand they also make it very manouverable (great for avoiding pedestrians on the sidewalk).

This morning . I took my ebike to downtown Vancouver, touring around English Bay and Stanley Park. The whole trip recorded 43 km.

On most roads, I could manage 30-38 km/h.
Pedalling is only used to assist starting. Pedalling could not be used if the speed is over 20 km/h due to one pedalling speed.

On gentle slopes about 25 km/h. If I had multiple gears I would pedal assist to 30 km/h for this gentle slope and also save battery energy.

On difficult slopes about 20km/h with pedal assisting. I don't think that I could pedal only on these slopes.

Around English Bay and scene routes 15km/h mainly by pedalling. Bicycle-style ebikes on these routes will be definitely more friendly than Vespa-style ebike.

On the way back for the last several kms, I could only do 20 km/h or less because the batteries were EMPTY.
Voltages for the stock 24 V 12Ah battery: 12.03V and 12.03V (EMPTY).
Voltage for the added 12V 14 Ah battery: 11.68V (too weak).
It seems the 14Ah has less Ah than the stock 12 Ah.

Comments:
1) There were no heat problem in both controller and motor when working at 36V battery. Both controller and motor remained luke-warm during the whole trip.
2) Higher speed and better accelleration.
3) The stock 24V 15A controller could work at 36 V happily.
4) One could ride the 36V version with much pleasure than the stock 24V version.
5) Lastly, I am very tempted to try it on 48V!!!

Test results with output waveform could be seen at:

http://endless-sphere.com/forums/viewtopic.php?p=22972#22972

Test results with output waveform could be seen at:

http://endless-sphere.com/forums/viewtopic.php?p=22972#22972

I have added the additional 6 volt battery to bring it to 36 volts and I am getting similair results to you. Max speed approx 35 km/hr and better acceleration and hill climbing. I haven't done any distance tests yet.
One question I have is why the Strong GT-S210 gets mileages of >50km with a similair battery pack of 36v 12ah and it is a much heavier bike. Is it that much more efficient? Do the large tires give it that much less rolling resistance? Or do they discharge their batteries to the point where they offer no assist at all?

One question I have is why the Strong GT-S210 gets mileages of >50km with a similair battery pack of 36v 12ah and it is a much heavier bike. Is it that much more efficient??

It has a higher power motor and seems to be so.
The strong has 21 speed so that one could pedal assist at any speed (even upto 35 km/h).
With only one speed on AL1020, it is very difficult to pedal assist over 20 km/h. If AL1020 has multi-pedalling, one could pedal assist at easy to extend it to a longer range.



Do the large tires give it that much less rolling resistance?

Yes, I think so. 26" wheel seems to have less resistance because my 26" MTB with 21 speed is much easier to pedal.



Or do they discharge their batteries to the point where they offer no assist at all?
Not quite so.

All I have to say about the Schwinn fold able AL1020 is "WOW", i cant believe i can have so much fun on a bike! It happen at Canadian tires in Langley and i was speed walking around the store looking for the bike. Once i found it i start doing a circle check like i was buying a car. Moments later, a couple "at their 50s" walk up and we start talking whats the benefit of an electric bike. The man quickly start looking for the plug and switch to turn the bike on. After we found it out, He let me to have the first ride around the aisle. I pedal start and hold the throttle until I ran out of road. The Schwinn AL1020 felt a bit loose steering other than that its perfect. The frame was solid. Didn't give me a feeling its going to fall apart. I am 6 foot 4 and I can pedal comfortably without stressing my legs or my arms. Too bad I just missed the $100 off sale last week at canadian tires. oh well guess i'm going to wait for the next sale! The7 i will pm you my # after i come back from my trip victoria. thanks The7 and don't stop modding your bike. haha

I suppose a good question would be: how much do YOU weigh? I am about 6'6" and about 235lbs. While I can fit well on the bike, I find the 24V to be a bit sluggish underneath me (I got about 12Km before EMPTY). I would love to try mod one of our AL1020 bikes with the added 12V, but I don't know where to start. Is there a good place to get those extra 6V or 12V batteries? Also, can you post pictures of how you hooked them in serial?

Another question: How would the bike handle two batteries in parallel? Would this just increase the range?


John

I suppose a good question would be: how much do YOU weigh? I am about 6'6" and about 235lbs. While I can fit well on the bike, I find the 24V to be a bit sluggish underneath me (I got about 12Km before EMPTY). I would love to try mod one of our AL1020 bikes with the added 12V, but I don't know where to start. Is there a good place to get those extra 6V or 12V batteries? Also, can you post pictures of how you hooked them in serial?

Another question: How would the bike handle two batteries in parallel? Would this just increase the range?


John

12 km range for people of your size for 24V12Ah battery sounds a little low. 20 km range is reasonable on flat But it depends on the condition of road.

For 36V, connect the extra 12V 12Ah battery in series with the stock 24 V 12Ah battery.

For 2 in parallel, top speed will be remain the same but you may feed better torque because the parallel batterys could maintain the voltage at high current. The range will be more than double.

Further modification:

Bought an used 48V Xtlye controller to replace the stock Ananda controller so that 48 V battery could be used for the motor.

The phase-sequence of Xtlye and Ananda are reverse such that same color connection will not work at all. Some modification is required to match the Hall sensor supply.

Initial bench test shows very promising.
With 24V and 36V, X-controller has the same results as A-controller. No-load top speed are 30 and 45 km/h. But X has a higher current limit of 19A ( vs 15A for Ananda).
With 48V, the no-load top speed is 61 km/h using X-controler. The expected top speed on flat would be 40+ km/h.

Will road test with 36V and 48V battery later.

Good work! 40+km/h makes the 1020 start to look interesting, and it would be priceless to pass roadies on a Canadian Tire folding ebike.

12 km range for people of your size for 24V12Ah battery sounds a little low. 20 km range is reasonable on flat But it depends on the condition of road.

For 36V, connect the extra 12V 12Ah battery in series with the stock 24 V 12Ah battery.

For 2 in parallel, top speed will be remain the same but you may feed better torque because the parallel batterys could maintain the voltage at high current. The range will be more than double.

That 12km was actually about 14km.. It was our first ride on the bikes, so it was a bit lower. Today, on our second charge since purchase, we went about 21km on a slightly hilly paved path and still had one light showing. My GF is 110lbs and she had two lights left lit on her bike.

Do you have a recommended place to buy a 12V battery? I wouldn't know where to look.

The speed is fine for me (local path laws kind of cut down what you can do), I just want more range out of it. I was even considering just buying two, and swapping the cable from Bat 1 to Bat 2 when the first one dies. In your opinion, would there be any extra stress on the controller to use two of the original 24V batteries in PARALLEL?

J

All of this info can be great for other owners of this bike.. We should set up a small micro site with a small forum for this bike. :)

No extra stress on the controller with parallel packs. 12V SLA batteries can be found almost anywhere. If there are no battery specialists near you, try a motorcycle shop.

No extra stress on the controller with parallel packs. 12V SLA batteries can be found almost anywhere. If there are no battery specialists near you, try a motorcycle shop.

Ahh yes, I did a quick search and found some local battery dealers. I might just buy a second original 24V from CT and run 2 in parallel. I also plan to find a keylock to control the flow of power so I can have a handlebar-mounted ignition key. :)

I converted my Crystalyte controller to a keylock switch instead of a push button. Highly recommended if you're a commuter and have to lock your bike up.

Do you have a suggestion of where to find such a lock? I did some searching and came up empty. :(

Try an electronics shop, or security/alarm place.

Further modification:

Bought an used 48V Xtlye controller to replace the stock Ananda controller so that 48 V battery could be used for the motor.

Will road test with 36V and 48V battery later.

Bad news:
The X-controller died on the first day of road test with 36V battery after a few minutes.
At first, it was suspected due to faulty FETs.
But it was found later due to an faulty driver (IR2101S) for the yellow low side FET.
Why the driver failed is unknown. It is an used controller and could die of old age.

Will use the stock controller at 36V until further action.

Bought another newer version 20A X-controller (also used) and after a long bench test.

It was finally road test this afternoon.
Excellent weather.
Temp 20 C.

Using 24V and 36V (sorry don't have 48 V battery at present)
With the 20A X-cont (Crystalyte controller).
Hard driving (pushing to the battery current most of time) about 18 km
With 20A limit at 36V battery, the motor did take peak power of 720W
Battery voltages at end of test = 12.23V, 12.22V and 12.14V


Comments:
1) Top speed at flat at 24V and 36V are not much different from
A-cont (Ananda controller 15A).
2) The accerelation is better with higher battery current limit of 20A (vs 15 A of A-cont).
3) Faster speed on slope due to a higher battery limit.
4) Battery current limit is same (about 20A) for 24V and 36.
5) I could ride a bit faster due to better torque and higher battery current limit
6) The motor and the controller were only lake-warm during the road test.
7) X-cont will stay in AL1020 with A-cont as spare.

Will road test with 48 V battery when available

Using 36V battery on road test again using 20A X-controller this afternoon:

1) The ebike pulled up slopes with higher speed (about 3 -5 km/h faster than that of 15A A-controller)
2) On flat, it could reach and cruise at 35 km/h with greater easy.
3) Soft start is also in incoperated in the brake switch. That means that you press the brake and twist FULL throttle, the ebike motor remains OFF. As soon as you release the brake, the motor will still ramp up to FULL throttle effect slowly by soft-start circuit. This is not the case with A-controller.

Finally using 48 battery on 20A X-controller at AL1020 ebike:

The 48V was composed of 2X12V12Ah (stock) + 12V14Ah (car jumper) + 12V7Ah (car jumper)

After 10 km of hard riding, the batteries read
12Ah => 12.79V and 12.80V (<70%)
14Ah => 12.74V (<70%)
7Ah => 12.21V (<25%)

Using fast accelaration such that the battery current reached its limit of 20A most of the time. Riding with FULL throttle on most road if possible.

This afternoon, the weather is very good.
Temperature = 19 deg C.

1) Top-speed on flat = 45km/h (c.f. 35 km/h with 36V battery)
2) Speed on gentle slope = 32 km/h (c.f. 25 km/h with 36V)
3) Faster acceleration with better torque.
4) Better control with reserve power at same speed as that of the 36V battery.
5) The motor and the controller remained lake-warm during the hard test.
6) Peak input power = 48X20 = 960 watt
7) Seems there is no problem to maintain an input power of 500 watt at 48V.
Now going to shop 2 new 12V12Ah to replace the temperary car jumpers.

Wonder whether it is the fastest foldable 16” ebike ! ?