Endless Sphere

Thanks Mike, I figured I would only need one of them.

Of all the weird redundancy measures... Surely a couple of 200 ohm resistors on either end of the pot would create a safe buffer and protect against accidental WOT or chopped?

Seems as good a place as any to post... I'm looking for an electronic throttle for a car conversion I'm working on. Looks like many late model vehicles (and all electric vehicles :wink: ) use a dual potentiometer system. That is, instead of the usual 3-wire pot (5 V, analog wiper and ground) you see...

This crazy contraption: https://www.facebook.com/TodayTonight/videos/1173124852726969/ Only flew because of the massive pile of LiPo I built for it. It was about 6 kWh of 40 C peak cells. The system was powered by six separate motors and controllers, each running on a 100 volt bus. In hindsight high...

Yeah when you look at the major loads in an EV, they probably stack up like so: Driveline (inverter, motor): 100 kW+ Aircon: ~6 kW Heater: 2-5 kW Pumps_fans: <1 kW Headlights: ~100 W So anything that draws more than 2 kW is best run from the traction pack. At 12 volts, 2 kW is 167 amps - far too muc...

Not sure if this is the best place to put it, but in any case, I recently got a quote to send batteries from Australia to the east coast of the USA. I had an enquiry about a 5 kWh battery build, which I'm happy to do, but shipping it to Baltimore was going to cost AUD$1766. This was for a 1 cubic me...

I have some data on the specific heat capacity of a Li-ion cell in my literature collection. I'll dig up the relevant papers, but from memory it was a range between 1100 and 1700 J/kg.

My shipment of 7000 mAh pouch cells is due to arrive in a few weeks time. Unfortunately all of 1100 of them are spoken for, but if you want more let me know - minimum order is 1000 unfortunately, and at $20 AUD landed they aren't cheap (but no worse per Wh than the other FEP cells). Stand by for som...

cheeko wrote: ↑

May 14, 2018 12:21 am

Hi i wouldn't mind this for 22S6P can you let me know if i can get them.

I bought 1000 of them and sent 200 across to Ryan in Brisbane (I think he needs all of them though). If you need 100 or so I can send you some of mine.

Interesting thing about voltage, is that after about 350 volts, you're dead. From 350 to 1000, you're still dead. Above 1500 V, you're dead and cooked, so the neighbours have to smell it... My point is, provided the drivetrain is designed properly, voltage is just a number. After 1500 V there are HV...

I'm looking to do some thing similar with some iMiEVs here in Perth, but a few Nissan Leafs are in the same boat now. Try to use the existing BMS wiring looms and so on, so that there's minimal interruption to the current system. And a Liquid cooled battery is quite feasible wit the Leaf packs - hea...

Consider using an intumescent material between and around the cells. It will hold the fire back for a while and buy you time.
Firestop is a popular material.

Otherwise polycarbonate is a fire-suppressing / self extinguishing material which can work well in the right structure.

Every BMS on a vehicle other than an e-bike uses a monitoring system and an electromechanical breaker. Cars, motorcycles and any other large EV doesn't bother with FETs for allowing or disallowing current to flow; it just opens a contactor.

So the rapid increase in CO2 concentration co-occurring with the industrial revolution is purely coincidental?

Im sure you dont need reminding that use of fossil fuels only contributes <4% of all CO2 emmissions. I had to read and re-read this. I presume you're referring to the total planetary CO2 production? As a global system, respiration produces most of the CO2, and photosynthesis absorbs almost all of t...

Personally I think the 1 C discharge test is one of the most useful figures a manufacturer could quote. Testing at some rate which is so far below normal operation for a capacity test is a bit like shaving your pubes to make your Johnson look bigger. If you know you need 15 amps continuous to push y...

+1 on temperature control - it's probably the number one factor in cycle life. If you can hold the cell temperature as close to 20'C it will live a long life. Ambient can be constant, but the cell will heat up and cool down a lot as it cycles. It's the same benchmark everyone else uses, so there's n...

The innards of that old forklift are amazing - the things we did before power electronics eh?

I've found Admiral Steel in the USA to be pretty reliable. They sell it as a 150 mm wide, 914 mm long sheet. You just cut what you need in the shape you want.

In terms of outright energy density the Panasonic 18650GA cells are up there, but only at very low C-rates. They claim 3400 mAh, but I've tested them at less than 1 C and never got more than 3100 mAh, and plenty of sag. The 30Q cells might be the best compromise.

No, you only gave a shit about supercapacitors when you learned there was an opportunity to bash lefty/greenies

Nuclear is the answer ... Nuclear is an answer, but it might not be the best answer. One of the upshots of a tightly regulated nuclear industry is that you know exactly where the material is at all times (within reason). Your typical fleet of Filipino seamen will be the cheap part of the crew now t...

Modern sea-container ships travelling slower than ever before: https://www.theguardian.com/environment/2010/jul/25/slow-ships-cut-greenhouse-emissions Almost as slow as sailing ships. Granted they can carry a lot more stuff, but super efficient electric / wind assisted shipping seems entirely feasib...

Awesome - thanks for that Warren!

Makes sense now. Looks like a solid design.

Re: the media - yes the focus on 'balance' is the source of this. Everybody can see how successful Tesla has been in the grand scheme of things, so rather than leave it as is, reporters and commentators will double down on the criticism and scrutiny... I think the inter-cell insulation is no doubt f...

@Pajda - just my thoughts and observations. I know that earlier reports suggested a radial cooling approach where the cells were glued to the micro channel extrusions, but they aren't obvious from this video. Also, it's hard to see where the coolant enters and exits the battery pack other than the b...