[pogo0120]

Are you saying children should not ride two wheeler?

I still don't understand. I am stating facts. People use two wheeler to carry children to school, hospital and for most people, it is the primary means of transport.

Back to ola S1, the battery pack design seems to be 6500mAmpH if it is 120Vpack level with 3.7 or 3.8V cell.

Still I am wondering what is there in the hump?
Also, I am doubtful about this design if people start loading stuff on foot board. For eg, for some minor house repairs, I brought few bricks in my Activa. if anyone has a user manual after purchase, If they could share, may be more light will shed on loading issues,

Regarding rain, I am still concerned. Foot board gets exposure to sunlight when parked, unlike inside of seat compartment. Foot board also gets exposed to water while washing, raining etc, unlike seat compartment. Not sure how things will work out in long term.

[pogo0120]

Some useful info on battery capacity. I know that 21700 cells take up to 5500mamph.. may be ola has a 6600 mAmph. Otherwise it will be 6 parallels with 32 in series.

https://www.google.com/url?sa=t&sour...QE_A06ait994LZ

[drt_rdr]

Originally Posted by Lobogris

I don't see why you are trying to justify a dangerous practice that would put a small child at risk. If the child loses his or her grip and falls off the scooter, the consequences can be disastrous. Just because many people are doing it is not a justification. Here at TeamBHP, we absolutely condemn any unsafe driving practice without exception. Otherwise why use seat belts or a child seat as many people don't do so?

This is an overreaction. A child could also lose grip and fall off the rear seat of a scooter\motorcycle. So, where's the advocacy for banning children off 2 wheelers altogether? While we're at it, we could also get a ban to prevent them from riding bicycles till they're voting age too. If you look up the accident stats of 2 wheelers, we would be better off banning adults from riding 2 wheelers too, right?

[efuture]

Originally Posted by aim120

From battery cell picture, it has a 120v pack 32s5p.
Because of the higher volts, the motor and electronics is more efficient compared to ather which has a system voltage half of ola.

I do not know how you calculated 32S here, but i'm 100% sure its not 5P from that picture.

My guess from the picture - It must be 2170, even Ather moved to 2170

1. The series connection is not from left to right (longer length side)
2. Most probably the positive is starting from her left hand side, since she is holding the positive probe in her left hand - total 4SxP
3. Then the long busbar on top is going to the next set of 4SxP on the left side of the picture
4. Now these 2 * 4SxP adding up to 8SxP, so she must be measuring 3.64*8=29.12V. Normally NCA's are 3.60 to 3.65 depending on brand, so took the average for calculation, no idea if it is Panasonic or Samsung - LG do not have NCA to my knowledge
5. I'm assuming 16P based on the picture - not sure since the picture is not clear. Assuming 4.75Ah per cell which is the market average for 21700. For 16P at 4.75Ah, the total capacity would be 76Ah
6. Since the total pack energy is only 3.97kWh, I don't think it is going to be 120V at 76Ah. 32S16P -> 116.5V*76Ah = 8.85kWh
7. So it should be 2 * 8S16P modules 16S16P -> 58.2V * 76Ah -> 4.43kWh which is again more than the listed 3.97kWh
8. My guess is that the usable energy is 3.97kWh out of the total 4.43kWh or it may be 14S16P-> 51V*76Ah = 3.9kWh which is close to the rated 3.97kWh, with 2S lesser to accommodate BMS and other electronics

Hope someone will do a teardown and share it in Youtube soon.

[DIY410]

If its NCA chemistry it has to be a panasonic, they also had a odd size of 20700 instead of the 21700.

Do note you cannot use high mah battery in low voltage packs. Take for example a samsung 21700 battery you get two types one with high capacity upwards of 5000mah but can only discharge at 1c and any higher will need liquid cooling or else it goes to thermal runaway and then you also get 3000mah cell but this one can discharge at 10 to 15c before it needs liquid cooling.

On a tesla they get away using high mah batteries with higher resistance then low mah batteries with lower resistance because in a car system voltage is much higher then two wheelers. Volt x Amps =Watt.

So if they are indeed using a NCA chemistry that falls under high mah capacity but high internal resistance which means it can only discharge at 1c. So to make for the low amps that it can give you run it with more in series.

Ather on the other hand isn't using NCA, since it has a low pack voltage it has to be a NMC type chemistry with low internal resistance and high discharge rates.

[efuture]

I don't know if anyone can confirm if it is Panasonic or Samsung or any other brand from outside. I know Panasonic and Samsung NCA cylindrical cells are available in the market now. Also my market knowledge is very small, I don't know if any other brand have NCA cylindrical cells.

To my knowledge, there is no limitation on number of cells in parallel (Ah) irrespective of voltage of the pack. If you have any reliable literature or low voltage pack design reference, please share the same, it would be really useful for many and especially I would be really happy to learn them.

I do not want to comment on c-rate because it is impossible to discuss on them without knowing the cell and pack characteristics. On energy cells and power cells, yes energy cell can only do close to 1C, but it can do 2C or 3C for 10 to 30seconds based on cell model. I don't think OLA would risk their billion$ company with cheap ON/OFF based BMS. This scooters might have current derate option based on cell temperature and SOC. BMS will continuously monitor temperature of the cells and based on the temperature, max allowable discharge power will be communicated to vehicle controller or motor controller depending on their architecture. This will help reduce the further rise in temperature. Again these are my guess and I think it is difficult to comment/confirm any of these form outside without knowing anything about the actual design.

I can prove that its not 120V pack from the picture in previous post and I have given my detailed explanation. If you feel it is different please share your theory.

[DIY410]

Originally Posted by efuture

To my knowledge, there is no limitation on number of cells in parallel (Ah) irrespective of voltage of the pack. If you have any reliable literature or low voltage pack design reference, please share the same, it would be really useful for many and especially I would be really happy to learn them.

The limitation is not on the battery but rather the speed controller and the motor. Running a low voltage speed controller rated to say 8kw will needs more cooling, thicker pcb traces, beefier mosfets, since more current flowing creates lots of heat. Same goes to the motor, the windings will need to be thicker and as will the battery cable to carry more amps.

Even in off grid solar inverters which convert DC to AC, the one which uses more panels in parallel weighs a lot more vs a inverter designed to use more panels in series, same goes to the solar panel wiring you can get away with a 4sq.mm cable for a 5kw solar inverter with series connected panels where as the same 5kw capacity inverter designed to take more panels in parallel would require 16sqmm wires.

Originally Posted by efuture

I do not want to comment on c-rate because it is impossible to discuss on them without knowing the cell and pack characteristics. On energy cells and power cells, yes energy cell can only do close to 1C, but it can do 2C or 3C for 10 to 30seconds based on cell model. I don't think OLA would risk their billion$ company with cheap ON/OFF based BMS. This scooters might have current derate option based on cell temperature and SOC. BMS will continuously monitor temperature of the cells and based on the temperature, max allowable discharge power will be communicated to vehicle controller or motor controller depending on their architecture. This will help reduce the further rise in temperature. Again these are my guess and I think it is difficult to comment/confirm any of these form outside without knowing anything about the actual design.

I can prove that its not 120V pack from the picture in previous post and I have given my detailed explanation. If you feel it is different please share your theory.

Even if its a NCA chemistry from the koreans, the same principle applies.
Since people are riding in warp/hyper modes for a long duration. A company like ola or ather cannot bet that the battery will used for 3c for 10seconds only.

We know the system voltage of the Ather, so they will have to uses batteries like the samsung 30T or 40T which are rated for 30Amps, with their system voltage they are not using NCA chemistry, otherwise you can forget about warp mode, even sports mode will cause it to heat up.

Ola for fact uses NCA chemistry and there motor power is a lot more, so they can only go for a pack with higher voltage.

[efuture]

Originally Posted by DIY410

The limitation is not on the battery but rather the speed controller and the motor. Running a low voltage speed controller rated to say 8kw will needs more cooling, thicker pcb traces, beefier mosfets, since more current flowing creates lots of heat. Same goes to the motor, the windings will need to be thicker and as will the battery cable to carry more amps.

I agree on low voltage and high voltage vs current and low and high resistance, its universal. What are you trying to say here? OLA S1 has high voltage pack? If so please share your valid theory. I really don't understand what is your point and what are you trying to prove. Please be specific on what your are trying to say, it would be really helpful for many learners like me.

Originally Posted by DIY410

Even if its a NCA chemistry from the koreans, the same principle applies.
Since people are riding in warp/hyper modes for a long duration. A company like ola or ather cannot bet that the battery will used for 3c for 10seconds only.

We know the system voltage of the Ather, so they will have to uses batteries like the samsung 30T or 40T which are rated for 30Amps, with their system voltage they are not using NCA chemistry, otherwise you can forget about warp mode, even sports mode will cause it to heat up.

Ola for fact uses NCA chemistry and there motor power is a lot more, so they can only go for a pack with higher voltage.

I really don't understand the comparison on Ather and OLA cells here, infact I don't see a difference between them. Both are using high nickel cathode (NCA & NMC) which proves both are similar irrespective of manganese or aluminium. Unfortunately it is what it is, not just OLA or Ather, all OEM's are depending on this 10s (High cylindrical) and upto 30s (pouch and prismatic) peak discharge power if they are using energy cells. But this doesn't mean the hyper/warp modes are not repeatable. I don't know if anyone has tested this in ather and OLA yet. May be some one can test the repeatability of warp and hyper mode in these scooters and share the result.

Again only OLA know their design and battery pack and I cannot comment from outside without knowing anything about their pack design and vehicle performance target. Anyone can guess but i'm really surprised to see your conclusion with just two images. Lets close this here, you have one two pictures - Invoice and one module, I'm guessing the pack is less than 60V based on those two pictures which is the only authenticated and valid proof from OLA and i've listed 8 points why i'm guessing so. Please prove my guess is wrong, I'm really happy to learn from your observation.

[pogo0120]

May be a skeleton section like this would have helped to understand Ola scooter better.

https://www.youtube.com/watch?v=0CwomabgDj4

Ola is packing 1 KW more in the same space as Ather.
Ola should give more technical details to gain more faith in their products.

[fordday]

Originally Posted by pogo0120

Regarding rain, I am still concerned. Foot board gets exposure to sunlight when parked, unlike inside of seat compartment. Foot board also gets exposed to water while washing, raining etc, unlike seat compartment. Not sure how things will work out in long term.

Concerns of footboard getting exposed to sunlight and water is valid. But isn't Ather battery in the footboard too, although a flat one? Are there any incidents with Ather battery? Would be good to know.

[fordday]

Took the test drive today of OLA S1 Pro. What to say. All the earlier reviewers have made all the observations. Here are a few from my side.

Sleek package and everything about it is sleek and oozes thought and design engineering. I love curves and hate edges and corners. This scooter satisfies that perfectly.

As someone said the SEAT is a sofa. Yes, its wide, soft and sticky for rider. My Activa pushes the rider to the front by a few mm on every braking action. I need to slide back my back after a few kms. Ola has it all good.

Three modes Normal, Sport and Hyper can be changed on the move. It gives an audible alert on change. Tried the Hyper mode many many times, simply mind blowing. On full throttle it feels almost like sitting in an aircraft taking off, except that you need to hold the handle bar tight and no backrest to feel safe. I can foresee youngsters doing all kinds of stunts on the roads with the hyper mode.

Couldn't test if one full face helmet will make it into the under seat storage. I hope it will. The steward said for two helmets to go in, only the Ola supplied helmet (half face) or its equivalent size will be possible.

The indicators when turned on gives an audible beep on every flash. They are not auto turn off like Ather. You need to press the same button again to switch it off. Coming from normal scooter, I pressed the opposite button (as in muscle memory) and the indicator switched to the other one.

There is no main stand. The protruded part of side stand fouls with my shin. While coming to stop or on standstill, it tends to touch on the shin bone or the lower calf muscle.

Lag in response. I was specially looking for it and found this many times. One scenario I could reproduce. Apply brakes to come to almost standstill like 1 kmph and then turn the throttle nothing happens. It was scary.

Overall:
It has Torque, style, speed and fun. A complete package.

I think it will suit my wife, she rides a scooty pep now. Her work location is 1 km away. Obviously any ICE vehicle will create problems if this is the daily running and hers is no exception. She hates the starting issues and other associated tasks like filling petrol and such :-)

[DIY410]

Originally Posted by efuture

OLA S1 has high voltage pack? If so please share your valid theory



I really don't understand the comparison on Ather and OLA cells here, infact I don't see a difference between them. Both are using high nickel cathode (NCA & NMC) which proves both are similar irrespective of manganese or aluminium. Unfortunately it is what it is, not just OLA or Ather, all OEM's are depending on this 10s (High cylindrical) and upto 30s (pouch and prismatic) peak discharge power if they are using energy cells. But this doesn't mean the hyper/warp modes are not repeatable. I don't know if anyone has tested this in ather and OLA yet. May be some one can test the repeatability of warp and hyper mode in these scooters and share the result.

Lets close this here, you have one two pictures - Invoice and one module, I'm guessing the pack is less than 60V based on those two pictures which is the only authenticated and valid proof from OLA and i've listed 8 points why i'm guessing so. Please prove my guess is wrong, I'm really happy to learn from your observation.

So again what we know for a fact are the picture, ola chemistry and Ather battery voltage, motor kw of both scooters.
Ather with its lower pack voltage and the quoted kwh, its guaranteed to have a cell like the with a samsung INR type chemistry.
https://www.samsungsdi.com/lithium-i...ower-tool.html
These cells can discharge in excess of 20amps for a 2500mah 18650 size and upto 35amps for 3000 mah 21700 size.

Then you have samsung ICR type chemistry these can discharge upto 5amps for a 2600mah 18650 cell and 6amps for a 2900mah 18650 cell.
https://www.samsungsdi.com/lithium-i...ower-bank.html

Panasonic NCA chemistry can discharge upto 10A safely for a 18650 size cell. Like the 3400mah 18650GA.

We know the motor power of the ather 450x 6kw and motor power or ola s1 8.5kw. We also know the battery voltage and charger max voltage of of ather 51v, which means it has a 12s battery, since any lithium battery(except LFT,LTO,special HV versions ) out there as a nominal voltage of 3.6 to 3.7v and max voltage of 4.2v. Ather states its pack as 2.9kwh, but usable is 2.6kwh typically they quote the battery kwh based on the nominal votlage but many manufactures quote it on max voltage. So from all of this data, it has a 12 cells in series of cell capacity of approximately 3000mah.
At 4.2v per cell is fully charged voltage but as soon as you remove the cell from the charger it drops to 4.1v. So with 4.1v full charged voltage you get a 12s20p battery pack of 2.9kwh, with a nominal voltage of 3.6v you get 2.6kwh.
FYI when a lithium cell shows a reading of 3.6v its state of charge is about 40%.
If Ather uses one of those samsung ICR type cells, yes at 12s20p battery pack it can power 6kw motor, since that battery pack can give out 5kw to 6kw peak. But in doing so the temperature of the cell will be 65c or more.

But if they use a INR type chemisty, the same 12s20p pack can give out 26kw of power at 65c. It can do 6kw of motor power all day long until it runs of juice.

Now lets shift to OLA we know its a NCA chemistry and its a 8kw motor, which direction do you think ola went with to get more kw from the battery. volt x amps=watt. By increasing the battery voltage in series, they can get away by using cells such as NCA type chemistry.

NCA chemistry cannot discharge high amps like Samsung INR batter or king of the hill the Sony VTC battery series but they do have higher discharge rate then a samsung ICR type battery with higher capacity then a INR battery.

[DarthVeda]

Originally Posted by pogo0120

i am little concerned now with battery under foot board. We use this foot board for lot of things apart from keeping our foot down there. Kids stand while riding, 20 litre water bottles, gas cylinder if size permits and mostly cargo stuff, from rods, metals etc..

Is this designed to with stand the load? Activa does very well. Just go to any market and see how activa is loaded with stuff and it takes them like a champ.

Ather also has it on the same location albeit placed differently, i have carried all that you mentioned in it, no issues at all. You are fearing the unknown, which is ok, just don't think too much about it.

[efuture]

Originally Posted by DIY410

So again what we know for a fact are the picture, ola chemistry and Ather battery voltage, motor kw of both scooters. Ather with its lower pack voltage and the quoted kwh.....

Unfortunately your calculation and theory is wrong. FYI - Pack voltage and pack energy is calculated at 50% SoC (mid voltage) and not when it is at top of the voltage. Also discharge power at 100% is not equal to 50% and so on.., and discharge power (kW) at low SoC <5% will be atleast 20 to 25% less than the power at 100% SoC.

[DIY410]

Originally Posted by efuture

Unfortunately your calculation and theory is wrong. FYI - Pack voltage and pack energy is calculated at 50% SoC (mid voltage) and not when it is at top of the voltage. Also discharge power at 100% is not equal to 50% and so on.., and discharge power (kW) at low SoC <5% will be atleast 20 to 25% less than the power at 100% SoC.

I have said manufactures can quote as they wish, typically is quoted at nominal voltage which is 3.6 to 3.7v during which the capacity is less then 50%.
Exactly discharge power varies, as the voltage drops to compensate to get same kw you need more amps, so that is the reason Ather uses a INR type battery.

You must also factor in that as you draw more amps, battery voltage will sag. This is to a lesser extent in INR type cells, which are designed for this sort of high discharge applications.

My calculations atleast to the number of cells in series in ather is irrefutable. Depending on the battery cell capacity the number of cells in parallel can be different. There are only so many INR type cells out there of 21700 ranging from 3000mah to 4000mah. They cannot use high capacity ICR cells like those over 5000mah, since to match a single INR type cell for continuous high amp discharge they would need 4 to 5 cells minimum in parallel that would increase the cost because it will raise the kwh of the battery pack, you don't want to be doing that.