AEVA Forums

yes i remember that thread. id have to disagree that 72v 180AH will be any better than 144v 90AH though, unless the controller wasnt actually capable of maintaining rated motor side current (which is what gives acceleration off the line). unless there isnt enough motor inductance to maintain continu...

ouch.

when i went to kenards to borrow a car trailer to move my prelude wreck, they wouldnt let me take it without written documentation that my uncles landcruisers tow ball (which had its own suspension) was rated to 1500kg.
they really werent kidding it seems.

Matt

have a look at what the FETs (i assume for such a low voltage controler theyd b using FETs) are rated to. u might only have a part number, so google can help.
have a look at the caps, see what theyre rated to.
ditto for the logic power supply.

most controllers can be over-volted a litlle.

Matt

Richo: how would switching between 72v 180AH and 144v 90AH help with peak power output? surely the switching losses at low duty cycles cant be that significant? Tuarn: how are you measuring the 20% between 3.7v and 4.2v? is the 20% in AH or wh? is that 3.7v at 0.05A and 4.2v at 0.05A? it just doesn'...

30 40AH,
should be good for 10kw.

HINT: do insulate and do 2x full (ie 1C to 2.6v) discharge-recharge cycles right before the event.
get those cells toasty, they then might be good for 20kw.

Matt

alll good questions, unfortunately the file didnt have any background to it, i just recieved a notification that someone had uploaded it to the thundersky yahoo forum. the values jive with what i have experienced however. on a side note, i may have killed one of my cells. it seems a weak cell preten...

its a series wound motor rated to 48v.
increase the voltage, increase the speed.
same thing us EV'ers do with everything.

for a point of reference, the kostov 11" that white zombie used to use is rated to 36v, doesnt stop us putting 200v through it (except for maybe the arcing).

Matt

just one more point.
A123 cells are 3.2v nominal not 3.6.
so for 36v, you will need 12 cells (there are only 10 in a dewalt "36v" pack).

Matt

that must be one strong tandem trailer to have survived two accidents.
i trust both you and Kevin were ok?

out of curiosity, what car were you using to do the towing?

Matt

thought id upload some data i just scored from the thundersky user group:
TS-LFP90_sag.pdf

"The power is finally delivered to the rear wheel via a maintenance free cog belt."

bahaha now theres some optimistic thinking.

lol, i know....240v x 6.5 x 1.414 = 2200v DC bus at sag (so 2.5vpc) (so i can put it in breakdown at 6xrpm) lol, if i were to use 4000v IGBTs, not alot of current, say 250A for good measure? if i had that $15k i started my mr2 project with again, id be busy ordering stuff rather than dreaming :) pip...

didnt have to be from the US, but i does have to be low voltage. if i used a 415v motor, id need a DC bus of 3400v....starting to get a bit big...though feel the power between ur legs :D i was thinking of getting the a motor that was originally intended for 208v star, rather than do a rewind (i woul...

oops my math is a bit off...1400v 5AH would mean 880 cells or there abouts.

Matt

lol, yeh it is a few.
i was thinking 600 of those K2 26650P cells Ian reviewed, 1400v 5AH = 7kwh.
twice range of a vectrix....oh to dream lol

i might be a bit wishful in thinking a 5.75kw motor could do 9000rpm, though tuarn bench tested a 2kw one i think? at 9000rpm.

Matt

if you are going to go for chain drive, make sure you either use a motor intended for a chain drive, or reinforce the motor for side loading. most motors aren't designed with side loading in mind. The bearings will wear out much faster if you dont account for side loading. im liking the aprilla RS12...

the posts on the other threads were deleted because they are spam. spam is exceptionally counter-productive as a sales technique. i am willing to allow this thread (it is still public and searchable from places such as google), as long as you don't make sales pitches on the other threads. good ways ...

tempting.

Jack: bewarned, further spam on other threads will result in account termination.

Matt

looks like you found the posts aswell andrew....i couldve sworn i hadnt hit the delete all posts buttons yet

Hi Jack, You have found the create your own thread function, this is good. Please stick to this thread for discussion of your cells. I will be deleting your other posts shortly, please do not actively try and make sales on all threads, as this clogs the discussion. If someone posts a question specif...

hi Lowndsy,

yes wye means the same as star, and it is indeed the stator poles that are being switched (there aren't any other poles that are accessable from the outside electrically in a 3PIM).

Matt

lol....so something with faster current limit?
and maybe a big fat "this motor is too big u dolt" light?

loving the exporting controllers idea though, keep it up Ian

Matt

Hi Karl, Welcome to the association. 2000E+shipping is $AUD3800+shipping which is alot of money for what your are proposing. for that amount you can buy a factory built electric scooter that already passes local regulations, has 3500w and does 60kmh, then modify it with lithium for 5000w and 70kmh. ...

30A continuous wont bother a 20AH agm any. i used to run he 20AH silicon batts on my scooter at 40-50A continuous shortly before i changed over to lithium. You could always do a longer test if interested? (i only ran those batteries for 50 cycles or so, they were still fine, i just wanted to get my ...

Hi Karl, We have done group buys in the past, particularly for components that would have a significant variance in price from what an individual could buy from a retailer, and what a group could buy from a factory. eg, thundersky batteries. The group buys are usually handled by individual members o...