THANKYOU GM...... AND WOW !!!!!!!!!

[MonkeyMagic]

My cast 20" dual drive had an issue a few weeks back with the rear wheel controller failing.
The same controller gave me some grief prior with hall sensor problems. It also seemed it was not as 'healthy' as the front motor.

After waiting for an OK - GM have sent me my replacement controller that went in today.

Replacing the controller itself was very easy, after I soldered the wires I gave it a quick power up test that immediately told me my wheel had some 'balls' to it.... nice

Tonight I took it out for a test run, thinking it would be just like old times.... No way!! I rode up the street with a big grin on my face but still felt something was missing... Looking down I realised I had my front motor power unplugged!! I shrugged and plugged it in...HOLEY CRAP my bike absolutely HAMMERS!!!! I really need to run some numbers but applying full throttle my top throttle LED disappears and the orange middle one dims to half so I expect I am juicing my GM 48v12Ah pack to it's full extent.. Might have to watch this actually.

Previously the front wheel felt more powerful than the rear, now its the other way around!!

So THANK YOU  - GM for a quick turnaround, and resolving it as per my request. I simply told them my problem in a point form email, and around a week later I now happier than before!

I felt the forum needed another happy post in here because right now I'm ecstatic

Need to go now because not having dual drive for a few weeks I'm craving a late night cruise, it's a hot night maybe there's still a few girls out I can impress haha

peace out MM

[Leslie]

Sweet.


Yeah watch that voltage drop there.  One cell could be getting squashed. I watch for a slump larger than single cell.  Say nominal is 51v anything lower than 48.8v is a worry.  Give the pack a good balance charge for a few days and see if it improves..

There maybe some physics to explore here when calculating C ratings to Series and Parallel cells.  The resistance is too high in the pack and load too high over the packs terminals.

Best you take your voltage readings pre BMS from the battery terminals.  I have no idea how much resistance shunt GM puts into their BMS's but you may get a good slump at this point of the circuit under heavy loads. If the cells are good 40 amps should be possible.  I don't lose any lights at 50 amps with a 1c rated 15ah pack, and I even use a 40 amp solid state relay and 25 amp continuos thermal breaker which I should get a drop over these devices too .

[Leslie]

Need to go now because not having dual drive for a few weeks I'm craving a late night cruise, it's a hot night maybe there's still a few girls out I can impress haha

peace out MM

When you pick one of those girls up you will need bike no.2 to take her for rides.  HMM  I think of the Blood Hound Gang Discovery Channel song when I think of Monkey on night cruises now.  Thanks for that .

I stated over at ES that Ebikes can be a selfish pursuit, but it doesnt have to be that way.   I have three people in my family that rides them now.  Its really good fun to take a friend or someone special for ride on the ebikes.

I have a brushed motor bike and a MP running now, so I guess I am up to Ebike no.3.

Haaa take a trailer out with you when craving what monkeys crave late nights, and say hey wana go to some nice spot with a bottle of wine.  Any gal too big wont fit in the trailer  and you can say no to her friends.  Any gal with a sense of adventure and a few drinks in her will jump into your trailer.  One way to sort out who to take for a ride.  

[MonkeyMagic]

Yes well I'm hooking up one of these Turnigy's I have on hand sometime today. It will connect from inside the battery case and mount on top in front of me... Gotta be careful inside there. I've also decided that I'm no longer riding in the rain and will keep a couple of garbage bags handy just in case. The Turnigy has what looks like vents on the back so I assume it doesn't like water at all.

Just went for a ride to the bakery, I have bugs in my teeth from smiling, this thing flies! - At cruising speed applying full throttle I nearly fall off I love it haha

I couldn't find my camera when I was re-fitting the controller but I really should have looked harder. I used a 80W soldering iron to properly seat the high gauge wiring along with protecting the ground rail with epoxy to fend off any potential short from the phase wires.

Nothing else was touched. I considered pulling the heatsink off the failed controller to double up on the new one. I thought that was a great idea but decided to leave it as is.

Until I monitor the power, I don't recommend running dual drive at full power on a single battery - unless it's a single 36V 16Ah then you should be okay with the current.

I need to get a sticker printed for the back of my helmet that reads "SUCK AMPS!!"

MM

[MonkeyMagic]

Any gal with a sense of adventure and a few drinks in her will jump into your trailer.  One way to sort out who to take for a ride.  

You are so right !

Okay so that is by far the best reason to own a trailer, if I don't buy one I should make a 2 seater just in case I get really lucky LOL

No joke though, I have met a few girls just from sitting on this thing - excellent investment

[Leslie]

Any gal with a sense of adventure and a few drinks in her will jump into your trailer.  One way to sort out who to take for a ride.  

You are so right !

Okay so that is by far the best reason to own a trailer, if I don't buy one I should make a 2 seater just in case I get really lucky LOL

No joke though, I have met a few girls just from sitting on this thing - excellent investment

I think it's evolution callling to the Ebike ethusiasts.  Its the new cool in geek about to be born.  Not reborn because it wasnt as practical as it is now.

 Hot summer night,  Breeze in you hair, speeding past the line of people walking.  A good head light on the bars and a bottle of wine and thermist of coffee in the trailer.   35 kms and LVC has you stranded some where by the riverside, you pull out some crackers and wine and a blanket, sounds rather romantic. More so presumptuous, but this is comming from a dude in wed for 14 years.

[Leslie]

I am seeing a pattern and connections to the C rating P/S cell and peukert's effect under load.

I maybe able to make a standing rule about the condition of the cells and how much current it is capable of with just a bit of data.

Some pre knowledge of the GM cells capabilities would be a good starting point.  Like we know all chemistry and cell form factors perform differently under load and have different tolerances.

Say a fully charged GM cell can perform under a heavy load slumped to 3.5v for 20 minutes then drop to LVC.  13 cells @ 3.5v is 45.5v

You may see some lights dim at those voltages.  

You can hook your TWM (turnigy watt meter) after all your doovelacies too, to get how much voltage drop the rest of your gear like the connectors, switches cables and BMS a load has on the rails.  

For the people who have CA or watt meter after their BMS and stuff. No way is one way better than the other, just gives different reading for different purposes.

Hook you watt meter up straight off the cells will tell you the true watts being used.  Hook it up off the motor you know what voltage drops you get just on any gear before the power enters the controller.  Both results taken from either point of the circuit are significant, alone, and or compared together.

[Bikemad]

I need to get a sticker printed for the back of my helmet that reads "SUCK AMPS!!"

Like these:





And you might want a top to go with it:




Alan
 

[Leslie]

Yer the women will love that attire.  It reminds me of Suck Eggs though.  Maybe "Packing Watts" may roll off the tongue better.

[Andrew]

"You've been passed by the Power" on the back of a dirty denim jacket with the sleeves cut off 

[Leslie]

Green Power just pwnd yo car,

You realize how lame this all sounds?  Wow I just did 290 watts on my last trip.  Maybe enough to heat up cup of coffee.

To efficiency and beyond.

 

Nope still sounds lame. 

[MonkeyMagic]

Haha Alan that attire is great!! I think I might have to grow a beard and big muscles to wear it though LOL

Okay I'm pulling off the battery and the Turnigy is going in. I'll just connect it to the output to the Anderson connector to monitor total load.

I've also ordered some Anderson connectors from ebay. What I'm doing is cutting out another rectangle hole above the original GM one in the battery and adding a second Anderson connector on top. Changing the wire guage to 10AWG to both wheels should be more than enough. Then I'll install the second Turnigy also mounted on top of the battery, so I can monitor both wheels.

To top it off, because I want to monitor speed - I was going to make something custom with a big dual 7 segment LED display for speed but until I design and build it, I will end up buying a CA in the next couple of weeks so I can adjust the LVC etc.

Hey with the CA - does it have a shunt built-in? If so, that means I need to run my power directly to that first, before splitting to the 2 x Turnigy's correct?

[Bikemad]

Hey with the CA - does it have a shunt built-in? If so, that means I need to run my power directly to that first, before splitting to the 2 x Turnigy's correct?

I believe the shunt is a separate unit which is mounted remotely rather than being built into the display unit.
So it would be best to put it near the battery as you suggested.

Alan
 

[MonkeyMagic]

Hey with the CA - does it have a shunt built-in? If so, that means I need to run my power directly to that first, before splitting to the 2 x Turnigy's correct?

I believe the shunt is a separate unit which is mounted remotely rather than being built into the display unit.
So it would be best to put it near the battery as you suggested.

Alan

Hey great, it may be possible to mount it inside the battery end caps because there is a lot of room in there !!

I'll post this in more detail in another topic, but I am very close to working out how to change all the pie settings on the fly hehe

[Leslie]

The CA-SA uses a pre calibrated shunt that seems on the mark.  The CA will show you your speed, AH, current watts or amps on the top display level.  You can flick through the menu and there are more details even % of regen that runs through the shunt.



The shunt is a little bit bigger than a 50c piece.  It labeled in the above picture as Molded shunt 45 amps continuous.  Im pretty sure it handles 100 amps max.

The tacho (speedometer sensor) assembly and cable is strong and durable.  But be sure to tie the cable in a good position on the front wheel.

The CA mounting gear is simple compatible to odd shaped stems and sturdy enough to hold it still with big bumps.  A screw needed tightening on the rear mount of my CA to stop it from spinning from there it was all good.