I almost got cold feet about starting my thread after reading yours, so detailed and thought through… But now it is there!
Will be interesting, I read about it will check it out. Would prefer charge/discharge but will probably not be space for it…
there are some more to think about concerning ride safety and brakes etc than I’m used to from ebike. There you always have disc brakes and will not be thrown off if the electronics fail.
I need to try pneumies sometime.
Now that is interesting. What I heard so far is that DD are more or less incompatible with pneumatics, be it the 54KV elofty or TB 75KV. However, how is uphill performance with your 6 inch tires and what are the exact tires that you are using? Are you more on the heavy side, say 90 kg (198 pounds) and up, or more a light rider, say below 90 kg?
A question:
On the builds I have seen I rarely see any fuseing on the mains from the battery? How are you guys thinking about this, will the ESC burn and stop a major short?
Just my two cents, p42a is an amp powerhouse. I’d either find a unity on the forum, lots of those popping up around here these days. Or go for VESC, if you want all your amps available to you safely
I did this on my build. Check out the as150 switch I made: 150a bulletproof anti-spark AS150 [Gauging interest]
Yes unity would be nice!
About P42a, yes very powerful, the pack will be rated for 180A continuous.The pack will not be the bottle in this setup. But I will not use all that power, but I found no disadvantage with the cell… Very powerful, very high capacity, 8A charge and good lifecycle. But let’s see in real life. If I use it at say 100A max it will probably deliver with minimum sag and live a long life and if more power is needed it will be available.
Is that true? Can’t find a reliable datasheet online, but that’s a lot! IMR batteries list 4.2A as standard charge, maybe fast charge could be around 6A? 8A would be impressive
They’re fairly pricey
Here’s a useful spreadsheet for you to compare. Not knocking the p42 at all, just want you to see how a low amp ESC is a misuse of the P42a Glory
In the past year, I’ve hovered between 150 - 170 and I’m currently 165. I don’t really have any massive uphills around where I live but I do go up about 5 story garage and whilst torque is lacking from a standstill on the hill, I’ve found it adequate to pull me up. My motors don’t really get hot or even warm really (it is winter though) so I suspect I can get more power out of them if needed.
My feeling is this:
Compared to belts and geared drives, you don’t get the instantaneous torque with the DD but it is adequate or at least for me 
Great sheet, comparing specs! You dont need to be all sensitive with me. I am not married to these cells, just a piece of eguipment… and if there is info out there I always want to know both good and bad. From my point of view one of the advantages with a forum like this.
About p42a´s in general: battery strength and stamina doesnt go hand in hand, you rarely can have both strong amp pushing power and big capacity, 30T vs 40T. But in the p42a´s that seems to be true according to bench tests, it pushes current as the 30T and has more capacity than 40T. Which makes me a bit suspicious, but definitely worth testing in a drive train.
When comparing cells I trust this site. Extensive and trustworthy bench testing on different load settings from fully charged to lvc. Interesting stuff, see discharge graphs on 40T and P42a below.
P42a
https://lygte-info.dk/review/batteries2012/Molicel%20INR21700-P42A%204200mAh%20(Gray)%20UK.html
40T
https://lygte-info.dk/review/batteries2012/Samsung%20INR21700-40T%204000mAh%20(Cyan)%20UK.html
As seen on the discharge graphs the p42s will deliver more power on all loads tested during the entire discharge cycle of the cell. And at the same time deliver more total energy for all loads tested. Also interesting that it can deliver 30A continuous to lvc without exceeding 45C, meaning you can basically hold it in your hand. If you wish
Measured total capacity p42a vs 40T on 5A discharge are for example, P42a=3924mah, 40T=3779mah. What happens in the comparison after 100 cycles is still to be seen…
Anyway, I really like the Samsung cells 30Q, 35E, 40T. But the bench tests indicates that the p42a basically is a better overall cell, when new… Therefore it will be interesting to try it in a real drivetrain and let’s see.
Finally I agree that to release the full potential of 180 battery amps 12s in the drive train some serious esc’s will be needed. Dont know if the TB DDS can take the power or if I can… And I hope that wont be neccesary to put a grin on my face However I know from experience that torque is addictive!
@rusins 8A charge? I dont know but on the lygte site he states the official spec as below. Standard charge 4.2A, max charge 8.4A. His source I dont know, but if he say I trust. If true, will provide excellent stopping power!
Thanks for the comment, long reply…, Cheers
Thanks for providing those details. What are the exact tires that you are using? Got a picture perhaps?
thanks <3 I’m actually super proud of it. If there are any other batteries i should add, lemme know.
Its a very powerful tool with all the filters/ sorting and such
P42s rate very well on the sheet. the specific power (Watts per kg) are 150% of the 40T a
Looks like they beat out the 40T at everything. and the price difference is only $30 or 10% on a 12s4p pack
I think it would be useful to have the vtc5d and vtc6 cells in there as well. Nice work.
So the P42a cell is advantageous in almost every, if not all, aspects over the 40T except price?
Seemingly. You get marginal performance increase across the board and significant wattage increase for an increased price per cell of roughly %10
That price difference has come down significantly over the last few months
If buying in EU, even the price is better. NKON is charging 5.75E for the P42a and 5.95E for the 40T. If buying 50 or more the difference increases. Maybe it is different in elsewhere?
https://www.nkon.nl/rechargeable/li-ion/21700-20700-size/molicel-21700a-4200mah-30a.html
Esc & bms update:
I will use a Focbox unity on the build. A guy an the forum had a new in box. I bought it. Will be great, no need to mess around with loop-keys and Flipsky switches. Also seems reliable and powerful. Still curious on Neobox power and reliability.
BMS
Will start with D140, charge only. Will continue to look for solution where I can limit charge to 4.15V and get individual cell reading via Bluetooth with minimum current draw when sleeping. Very reliable balancing. Contenders Neptun, jbd/ltt(30A), BieDieBMS.
@love2scoot There is a mod in the Neptun to allow supervised discharge of +100A. Includes changing the mosfet resistor to 1m Ohm. Thread on endless sphere forum. ”Supported” from the manufacturer. Seems to be very competent on the product, positive to mods and great customer service overall. Will be very interesting to hear your views when implemented on your build.
