methods 26kwh Emoli bug build

[evblazer]

The new motor is a few inches shorter that the last. It can still reach an honest 60mph but I have to really pay attention to my foot. I have gotten this motor hot enough to light a cigarette already The motor came with a thermal switch that is set to 150C. The insulation is class H so it is rated for 180C. You can smell the motor cooking long before it sees significant damage.

Good to see it up and running and lighting a cigarette on your electric motor might impress the ladies! I remember long ago reading on the evlist that the switch, at least on the old 9" motors, was more like a BTW your motor is dead notifier rather then a warning switch though so don't put too much trust in it
What rpms are you running it at? I always found the worst was when I climbed a nice long hill and had to stop at a light. I tried to put in in nuetral and keep the motor spinning some to keep it cool but I know my wife didn't do that! An external blower to keep air flowing could be good stuff.

[methods]

Good to see it up and running and lighting a cigarette on your electric motor might impress the ladies! I remember long ago reading on the evlist that the switch, at least on the old 9" motors, was more like a BTW your motor is dead notifier rather then a warning switch though so don't put too much trust in it

Actually I characterized the switch - it flips over right at 150C and the motor (or at least the insulation) is rated to run continuous at 180C. I would agree however - once a motor is that hot it is a matter of about 3 seconds at 30KW to put it over the edge. I dont have hte switch hooked to anything. I have pretty much figured out that if I can keep it at 10kw average (with only short bursts to 20Kw and 30kw) that the motor stays well below 150C.

What rpms are you running it at? I always found the worst was when I climbed a nice long hill and had to stop at a light. I tried to put in in nuetral and keep the motor spinning some to keep it cool but I know my wife didn't do that! An external blower to keep air flowing could be good stuff.

I dont know to tell the truth - I am mostly driving between 30mph and 40mph in second gear (78V) - so I am revving it. I did some tests on the fan - it is basically useless unless you really get it spinning - so I try to keep the RPM up.

I just scored two old VW blower motors for cheap. I am going to hook both of them up - each one blowing two "brush holes". I think that with this mod I will be able to hammer on it pretty hard.

Thanks again for the motor - really has lifted my spirits

-methods

[icecube57]

This seems quite fitting to you Methods.

[methods]

What rpms are you running it at?

I was ashamed that I could not answer this question so i went out and did some research.
Found the gear ratios, final ratio, stock tire size, etc.
Here is a chart - looks like I am running the motor a touch over 5k RPM when I am doing 40 in 2nd
(note that this table assumes stock tire size - so when I am going 40mph that is 45mph in the table - since that is how fast the motor is actually turning. I am not running stock tires)


Assuming a 155/80/R15

Code: Select all

	1st	2nd	3rd	4th	Rev
 	3.8	 2.06	  1.26	  0.89	  3.62
 	4.125	4.125	4.125	4.125	4.125
 					
500	2	4	7	10	
600	3	5	9	12	
700	3	6	10	14	
800	4	7	11	16	
900	4	8	13	18	
1000	5	9	14	20	
1100	5	10	16	22	
1200	6	10	17	24	
1300	6	11	18	26	
1400	7	12	20	28	
1500	7	13	21	30	
1600	8	14	23	32	
1700	8	15	24	34	
1800	8	16	26	36	
1900	9	16	27	38	
2000	9	17	28	40	
2100	10	18	30	42	
2200	10	19	31	44	
2300	11	20	33	46	
2400	11	21	34	48	
2500	12	22	35	50	
2600	12	23	37	52	
2700	13	23	38	54	
2800	13	24	40	56	
2900	14	25	41	58	
3000	14	26	43	60	
3100	15	27	44	62	
3200	15	28	45	64	
3300	16	29	47	66	
3400	16	29	48	68	
3500	16	30	50	70	
3600	17	31	51	72	
3700	17	32	52	74	
3800	18	33	54	76	
3900	18	34	55	78	
4000	19	35	57	80	
4100	19	36	58	82	
4200	20	36	60	84	
4300	20	37	61	86	
4400	21	38	62	88	
4500	21	39	64	90	
4600	22	40	65	92	
4700	22	41	67	94	
4800	23	42	68	96	
4900	23	42	69	98	
5000	23	43	71	100	
5100	24	44	72	102	
5200	24	45	74	104	
5300	25	46	75	106	
5400	25	47	77	108	
5500	26	48	78	110	
5600	26	49	79	112	
5700	27	49	81	114	
5800	27	50	82	116	
5900	28	51	84	118	
6000	28	52	85	120	

Notes:
5.6-15	 = true stock				
155R15	= equ				
165R15 common replacement					
					
					
It was 155/75 or 80 x15. Common replacement is 165/75x15 or 195/65x15 or					
185/70x15.					

methods

[amberwolf]

You might want to put a tach sensor on the motor shaft or coupler, to hook up to the tach on the dash. If you think anyone but you will drive it, you could also hook that up to a circuit that will alarm audibly and visibly to advise shifting or slowing down is absolutely necessary *right now* to prevent overspeed of the motor and destruction (which will look a lot like your old one when it happens). I don't know what RPM to set it at for alarm but the motor plate may say.

EDIT: looks like the plate says 3480RPM; at 5000RPM that's a lot over. Not sure what it's actual max RPM before exploding the comm is, but I wouldn't push it.

Was just trolling through YouTube and came across this neat VW electric bug damn quick acceleration too i thought

That RebirthAuto bug video shows one of the later beta tests of the Soliton1 controller; IIRC the transaxle broke not long after that on that bug from the torque.

[katou]

Are you testing the cells before assembling into a pack? That is a massive number of cells. I have a large # of Emoli cells so I'd be very interested in how you are weeding out the bad ones.

Katou

[methods]

You might want to put a tach sensor .....

EDIT: looks like the plate says 3480RPM; at 5000RPM that's a lot over. Not sure what it's actual max RPM before exploding the comm is, but I wouldn't push it.

Why not just use the tach signal to limit the throttle similar to how the CA works? That was my plan. That way you could just step on the gas and run it no load without any worries. Just like an IC engine. I will probably throw together an Arduino to monitor motor temp and RPM. Maybe even do it with the BMS so that I can display.

Bah - RPM is a guideline Though if you look at the efficiency graphs these brushed motors are not like our BLDC... They start to fall off at higher RPM due to brush BS. The sweet spot really is in the middle... I am mostly over-revving the crap out of it to keep the fan speeds up. Should have my new blower(s) in the next day or two so we will see how it works supercharged.

Are you testing the cells before assembling into a pack? That is a massive number of cells. I have a large # of Emoli cells so I'd be very interested in how you are weeding out the bad ones.

Katou

http://www.endless-sphere.com/forums/vi ... 39#p244776

I dont have time to weed or test them individually. I tested them in banks of 12P since that is how a lot of them came in.
I was seeing a huge range - from 26Ah to well over 32Ah - but I dont care because I call a 140Ah pack only 100Ah. At first I was collecting all sorts of data - by the end I was just checking to make sure they were not trashed. With 48P you can get away with a lot.

So... Where did you get your cells and do they have tabs?

As soon as I have a free moment I am going to make my new 48P solderless box.

-methods

[evblazer]

EDIT: looks like the plate says 3480RPM; at 5000RPM that's a lot over. Not sure what it's actual max RPM before exploding the comm is, but I wouldn't push it.

That 3480 is the max rpm of his blower motors he just sorta snuck that pic in there at the end. I don't recall a rating on the motor I sent the nameplate was rather void of any information. A post on the electric motorcycles list makes it look like methods is ok at 5k but unless you really know everything is balanced and the motor is very well tuned and overbuilt I wouldn't go much higher. It shouldn't fly apart at 4k.

"I have two of those motors over at Jim Husted's shop that just got 'loved
on' by Jim. According to Jim and John Wayland (who has info on these
motors), the factory spec is 6K, but like someone else chimed in, they
should be kept around 5500-5600 RPM. "
http://www.mail-archive.com/listserv@el ... 00442.html

[amberwolf]

Ah; somehow I missed that the pic was of the blower motor.

I have seen a number of general guidelines for max redline RPM on motors, generally based on their case diameter. I've commonly seen an 11" is generally rated 5000RPM max and 3500-4000 continuous, but sometimes a nameplate shows otherwise.

Here's a partial table of Netgain's motors, for instance:

1.GIF (28.52 KiB) Viewed 2189 times

[methods]

Actually that name plate was off of a 7kw PERM motor that I was thinking about selling.
http://www.zeromotorcycles.com/shop/ind ... ucts_id=50

But - speaking of blowers...

My two blowers showed up today. One draws around 150W - 300W and the other draws around 20W.
I picked up some fittings at Lowes and I should have it rigged up soon. I will post pictures - but for now I am really busy prepping for an event this weekend.

-methods

[katou]

My Moli cells came from toolpacks from a local tool repair place. After I figure out how to test them all, I'll weed out the bad ones. Yes, they have tabs. You just curious or are you shopping?

I thought that having each parallel strand about equal was best? I remember a thread from DocBass about how he carefully matched them all. I seem to remember LFP saying something similar in post somewhere...

Seriously, I thought it was really important that they all have (as close as possible) similar capacities?

Katou

[methods]

I thought that having each parallel strand about equal was best?
Katou

There is a small flaw in that logic. It sounds like you are assuming that you are going to string matched cells in series first, then tie these series strings in parallel. That would result in a nightmare situation where you have many, many balance taps all hooking together in a big mess.

What you actually want to do is sort the cells out into "bins" - call them A, B, and C
Then when you build up your pack, you want to build them in parallel first and series second.
If it were a 20S 6P pack then you would want each 6P chunk of cells to be comprised of A,A,B,B,C,C -> a perfect balanced mix of strong and weak.
You would then tie twenty of these in series and set up one set of balance taps.

The strong will help the weak, the high AH will make up for the low AH, the high impedance will be offset by the lower impedance.

Important? yes... Critical? No -> not if you have a random sampling and you are going massively parallel like I am.
I have 48 cells in parallel - somewhat randomly matched together - 960 cells in total. The prospect of actually trying to characterize 960 cells is just retarded. It makes much more sense to just hook them all up, drive the car, and when I am feeling especially ambitious - run the battery down until the first bank reaches LVC. That is obviously the "worst bank". I can then just replace that bank - or - better yet - I can then find the bank with the highest voltage, remove both banks, and take them into the shop.

Now we are working with a more reasonable number of cells to characterize: 8 banks of 12S2P.
Match the weak with the strong and reinstall

repeat until happy.

Successive approximation is much faster and easier than brute force characterization. Got me on the road ASAP where I can do cell testing with my ass and the gas pedal The doc is a brave man for sorting all those cells but he was only building a 2kwh pack where as I am in the process of building a 26kwh pack (10kwh running as of today). Just not worth the trouble.

If I were you - I would spend less time fretting about it and just build them up
Get your bike ready for this beautiful summer weather that is heading our way.
The last thing you will want to be doing is characterizing cells while everybody else is posting pictures of girls with big boobs riding ebikes in tiny bathing suits.

-methods

[katou]

Where would I find these posted pictures? I am always interested in build pics. Well built bikes with big healthy battery packs.

Thanks for the explanation, I understand your reasoning, and it makes sense. Your approach allows you to get on with the business of driving the vehicle, while providing information to match the packs down the road as needed.

I think that this will speed my battery building. I will have 15p myself, so that is right up there. I will just weed out the bad ones with my CBA III until I get something faster.

Knowing that the cells were used in parallel strings previously, that does simplify your pack building. You can (more or less) treat each parallel group like a single cell.

Katou

[methods]

Did the damn server crash again in the last couple of weeks?
WTF?

This is the second thread where postings I have made are gone. Very lame.

So behold the GHETTO BLASTER

Recycled heater out of a similar bug
Inlet facing forward to suck up that 60mph wind
Dual outlets blasting into either side of the motor

016_PERM.jpg (87.97 KiB) Viewed 1863 times

017_PERM.jpg (110.88 KiB) Viewed 706 times

018_PERM.jpg (96.97 KiB) Viewed 706 times

014_PERM.jpg (98.9 KiB) Viewed 706 times

Results?

F'ing awesome - that is what the result is. Those following the thread will know that i used to have a long can 6" motor with tons of torque and now I am running this tiny little go-kart / motorcycle motor and it really is being stressed. I have been keeping the average loading under 12KW and it has worked out .... but I really had to be conscientious. With this new mod I was able to run 32KW for 3 minutes straight and the brushes only got up to 100C and the can was hardly warm to the touch. In comparison - without the blower I was seeing upward of 150C on the brushes and the can was untouchable.

I declare at this point... Anyone who does not force cool their large format motor must be retarded
Cost me about $20 for the blower and parts.
Took my only 20 minutes to install everything - and that was after a very long day at the track racing - so I was functioning at about 15%

Yea.. yea... painters tape and zip ties are not a permanent solution.... But before anyone criticizes I might say that at least I am doing shit

"A proof of concept is worth 10,000 criticizing posts"

-methods

P.S. I have in my possession a 120V 1,200A Kelly controller. I think you know what THAT means. . . . .

[amberwolf]

P.S. I have in my possession a 120V 1,200A Kelly controller. I think you know what THAT means. . . . .

I smell smoke in the near future.

Question--is that blower higher off the ground than it looks? Cuz the first pic gives the impression of a caterpiller-killer.

Maybe you can sell the original motor as a repairable core to someone that does that kind of work, like Jim Husted. Better if they're local to you though, with shipping costs these days.

[BiGH]

Results?

F'ing awesome - that is what the result is. Those following the thread will know that i used to have a long can 6" motor with tons of torque and now I am running this tiny little go-kart / motorcycle motor and it really is being stressed. I have been keeping the average loading under 12KW and it has worked out .... but I really had to be conscientious. With this new mod I was able to run 32KW for 3 minutes straight and the brushes only got up to 100C and the can was hardly warm to the touch. In comparison - without the blower I was seeing upward of 150C on the brushes and the can was untouchable.

I declare at this point... Anyone who does not force cool their large format motor must be retarded
Cost me about $20 for the blower and parts.
Took my only 20 minutes to install everything - and that was after a very long day at the track racing - so I was functioning at about 15%

Yea.. yea... painters tape and zip ties are not a permanent solution.... But before anyone criticizes I might say that at least I am doing shit

"A proof of concept is worth 10,000 criticizing posts"

-methods

P.S. I have in my possession a 120V 1,200A Kelly controller. I think you know what THAT means. . . . .

I think i love this post!

makes me feel good about the fact I can only fit a 9" motor in an MR2.

EDIT: what was your average temperature at 12kw without cooling?

[amberwolf]

makes me feel good about the fact I can only fit a 9" motor in an MR2.

Don't be so sure about that:
http://www.diyelectriccar.com/forums/sh ... hp?t=34774
Somewhere in there toward the end he's got a bigger-than-11" motor he's working on sticking in his.

[BiGH]

makes me feel good about the fact I can only fit a 9" motor in an MR2.

Don't be so sure about that:
http://www.diyelectriccar.com/forums/sh ... hp?t=34774
Somewhere in there toward the end he's got a bigger-than-11" motor he's working on sticking in his.

Yes, true, but he's going through a lot of effort to get that motor in. I'm looking at running high voltage, and i don't think a kostov 22R or a Warp 11HV would fit. Once i have an mr2 though i'll be able to measure better

Australia's laws as to what you can do are so strict with regards to conversion projects. I've already had to put up for sale one donor car because the conversion can't pass

[BiGH]

back on topic... video of the blower running? I bet it sounds pimp.

[methods]

EDIT: what was your average temperature at 12kw without cooling?

That really depended on how it was driven. The problem is that the internal fan is very weak - you can not even feel the output from it until you rev the motor up over 3K RPM. So the term "12kw" can be very deceiving. If I tooled around in 3rd gear (translated low RPM) I could not even sustain 12kw - motor would blast past 150C and car would start to stink of brushes. If on the other hand I kept the revs up in the stratosphere I was seeing around 130C on the brushes - but remember all this is heavily dependent on ambient temperature, driving style, etc. etc.

Anyone who gives straight numbers is not telling the whole story.

back on topic... video of the blower running? I bet it sounds pimp.

Actually you cant really even hear it. Just a slight hum from inside the cabin.

Here is a note: If you want to try this attention must be paid to how the blower is set up. There is a weird thing that happens with blowers like this... if you apply too much back-pressure at a certain point it just stops pushing air - back off a little and the CFM go through the roof. I am sure Luke could explain why this is - but for a "flow retard" such as myself I just know that playing with the mounting setup while monitoring the actual airflow through the motor I found a sweet spot. The sweet spot was *not* and airtight seal.

This was just my $15 used VW blower though... If you purchase a pressure rated fan then it is all about sealing it up.

AW -> Ground clearance is really good on the fan - many inches. The picture was an optical illusion.

-methods

[BiGH]

That really depended on how it was driven. The problem is that the internal fan is very weak - you can not even feel the output from it until you rev the motor up over 3K RPM. So the term "12kw" can be very deceiving. If I tooled around in 3rd gear (translated low RPM) I could not even sustain 12kw - motor would blast past 150C and car would start to stink of brushes. If on the other hand I kept the revs up in the stratosphere I was seeing around 130C on the brushes - but remember all this is heavily dependent on ambient temperature, driving style, etc. etc.

fantastic thats exellent info thanks! I like the idea of high rpm driving pitty the brushes wear faster.

Anyone who gives straight numbers is not telling the whole story.

Completely agree. I was looking for a maximum temp that you were observing trying to keep it under 12kw. (sorry I didn't mean in a scientific way)

Actually you cant really even hear it. Just a slight hum from inside the cabin.

What about from outside of the cabin?

Here is a note: If you want to try this attention must be paid to how the blower is set up. There is a weird thing that happens with blowers like this... if you apply too much back-pressure at a certain point it just stops pushing air - back off a little and the CFM go through the roof. I am sure Luke could explain why this is - but for a "flow retard" such as myself I just know that playing with the mounting setup while monitoring the actual airflow through the motor I found a sweet spot. The sweet spot was *not* and airtight seal.

This was just my $15 used VW blower though... If you purchase a pressure rated fan then it is all about sealing it up.

AW -> Ground clearance is really good on the fan - many inches. The picture was an optical illusion.

-methods

excellent tip, it makes sense, as the motor would have a peak power level that couldn't be exceeded, but i'm no expert in fluid/gas mechanics either.

[katou]

I know a thing or two about blowers (or so I think), and the problem is the static pressure that the blower is designed to produce. Static pressure is how much pressure you feel if you put your hand over the end and cap it completely.

For instance, axial fans (like a room fan that swivels) has very low static pressure, nearly zero, I don't think you could even measure it in psi.

A centrifugal fan develops higher static pressure, which is why most things use them instead of axial fans. Axial fans are great for unrestricted airflow though.

General Rules
the thinner a centrifugal fan is, the less Cubic Feet per Minute (CFM) it will produce.
the larger diameter a centrifugal fan is (where the rotating vanes go from center all the way to the edge), the higher the pressure.
the faster the fan runs, the higher the CFM, but also the more noisy, and power consumption goes way up too.

Want to see some crazy stats on a blower? Look up blowers used for blast furnaces. They're nuts. Like 300 cfm at 20 psi or something, but I don't remember exactly.

If you want to know more, I highly recommend the David Gingery book, called "building centrifugal fans" or something like that. Excellent info pitched squarely at the sort of people we are.

Katou

[methods]

Eliot (Emoli bug) has a new friend.
Meet BlueBug.

002_Bluebug.jpg (58.13 KiB) Viewed 699 times

BlueBug has 72V of lead, a 4hp motor, Zivan charger, 450A controller, ~20 mile range, and a very classy 1966 body.

One of these fine bugs is going to get the 9" treatment soon (no Luke - not like when your Uncle used to come to your room at night.... A different kind of 9" treatment ) - just as soon as I can figure out how to un-max my credit cards That 120V 1200A controller is just growing mold on the shelf.....

-methods

[liveforphysics]

One of these fine bugs is going to get the 9" treatment soon (no Luke - not like when your Uncle used to come to your room at night.... A different kind of 9" treatment )

lol

[Arlo1]

One of these fine bugs is going to get the 9" treatment soon (no Luke - not like when your Uncle used to come to your room at night.... A different kind of 9" treatment )

lol

Lmfao! So you didnt just use lipo How about some 12kw continous liquid cooled outrunners for this? I know they are not sure what to use for a contoler but I might be able to find you someone Methy I love seeing work like this great job man!