New Magic Pie is going to land!

[Bikemad]

As now I have a slide rack maybe I could put the rocket there, then I let you do the first ride 
But something like 50% of them exploded lol.

As long as they don't explode, it looks like fun:

Rack mounted rocket

This one's a little bit faster

Alan
 

[GM Brazil]

I was going to link that 245km/h video But I forget it when writing the answer, lol.

[GM Brazil]

New photos!

The velcro solution = elegant and completly solved the noise problem

"oficial" better photo for the GM gallery

[Jazzjerry]

Good Idear with the velcro.

I Should try and find some as well

JJ

[GM Brazil]

I used some auto adehsive velcro at the battery. I tried to put the velcro around the sliding plate but I do not know why it does not work, it is better to put all around the rack, then was just perfect, NO NOISE!

There is some video I edited for the bike

http://www.teslabike.com.br/TeslaTeaser_0001.wmv

[GM Brazil]

Today I did the range test!

The MP with me 110km, 28,5 kg bike (measured!!) and something like 2kg of stuff (photo camera, lock chain, etc). The test place is very plane and any hills where very light.

Most of the time I set the cruise control to something close to 30km/h, but the first 20 minutes I was riding at maximum throttle all time. I did not use the pedal until the BMS cut.

I did a total of 25,6 km with an average speed of 20,9 km/h and a maximum of 43,5 km/h. Total riding time 1:20 with 7  minutes of stop (my lunch! ). This data is from the GPS. From the cateye (correctly configured) the maximum speed was 44,5 km/hand the distance 28,2 km (this distance includes my way back to home pedaling!).

I think the distance is pretty nice for 140kg of bike plus rider without any pedaling, and as I know the battery takes a small time using to really reach full capacity (is this true? I do not remember where I read that). Using the crap multimeter the battery first showed 51v!!! This voltage dropped as the battery cool down and got stable at 45,5V. Now I'll put the battery to charge and take note about the time to recharge (I'll turn the recharger on at the exact time I post this topic ).

One thing important is that the battery gauge lights at the throttle does only showed that the battery was at half of capacity!!! But when acelerating it shows only the empty led.... I think that I'll take the load measure as reference in the future, as even now with the battery cold the "half" led still light up!

As soon as the battery finish it's charge I tell you

ps.: The Velcro solution worked really nice!!!  Not any noise, very  very nice to ride the bike like this. Even with the "elastic hook" was not that smooth and sometimes the battery kicked with that!! This velcro should came with the rack kit as default!!!

ps2.:Total ride distance so far 117,8 km!!! This is almost 10 dollars in gasoline for my car here

[Hardcore]

nice, do you have 36v or 48v

[GM Brazil]

I started to recharge  at 14:45 and at 20:00 it finished.

I let it for more 30 minutes to balance the cells.

Hardcore, I have a 48v12Ah HM batterry, and now after recharging the multimeter shows 53,7v.

[Bikemad]

Using the crap multimeter the battery first showed 51v!!! This voltage dropped as the battery cool down and got stable at 45,5V.

Bruno,

Your earlier readings appeared to be a bit on the low side for a 48V pack, unless your voltmeter is really as bad as you say!

Nominal voltage 3.8V Mean voltage during rated discharge after rated charge
End of charge voltage 4.20 ± 0.05V

These figures are what I would have expected:

48V pack = 13 x 3.8V = 49.4V  (54.6V ± 0.65V fully charged)

Alan

P.S.
Your video is very good!

 
 

[GM Brazil]

Hello Bikemad!

So it seems ok, fully charged it is 54V (with is inside the "54.6V ± 0.65V fully charged")

Only the discharged state that was 45,5 volts after the battery cooled down. Was something closer to 49v (51v and going down) the first time I checked it after the ride.

So: 45,5v / 13 cells = 3,5v each cell is this ok?

But what I did not like is that the "battery gauge" at the throttle was showing "half" battery when the BMS cut-off the battery...

ps.: Thanks! My cousing filmed but he do not know how to use the zoom It could be better

[Bikemad]

So: 45,5v / 13 cells = 3,5v each cell is this ok?

But what I did not like is that the "battery gauge" at the throttle was showing "half" battery when the BMS cut-off the battery...

These packs can safely be discharge as low as 32.5V (2.5V/cell) without damaging the cells, but I expect the BMS cut-off is set at a higher voltage to extend the overall life of the battery.

I'm pretty sure the LED battery gauge was originally designed for use with lead acid batteries, which tend to have a larger and more pronounced voltage drop throughout their discharge, and this would be more obvious to the battery meter.

Alan

[GM Brazil]

So: 45,5v / 13 cells = 3,5v each cell is this ok?

But what I did not like is that the "battery gauge" at the throttle was showing "half" battery when the BMS cut-off the battery...

These packs can safely be discharge as low as 32.5V (2.5V/cell) without damaging the cells, but I expect the BMS cut-off is set at a higher voltage to extend the overall life of the battery.

I'm pretty sure the LED battery gauge was originally designed for use with lead acid batteries, which tend to have a larger and more pronounced voltage drop throughout their discharge, and this would be more obvious to the battery meter.

Alan

Nice to know that the BMS cut off earlier! There is someway to "tune" my battery gauge? I'll open the spare twist throttle and see if there is some way

I hope my watt meter shows up soon, it is taking too long to get here. Then I'll do an 1.5C resistive loading test and take notes each 5 minutes to draw the battery graphic and check if it fits the expected

One thing that happend is that after some regenerative bracking the battery comes alive again, and was possible to use the motor again but any higher aceleration and/or up hill it shut off again, I did this just once . Then I tested turning off the key and on again, the battery comes live again but I did not used the motor because I know that if the bms cut off, it was time to pedal back home and not to squeeze the battery

[GM Brazil]

Today it is 34ºC here. The pie turned off SEVERAL times, a few times after some long regenerative breaking. Two times at flat terrain at full speed and other few times due to current limiting at some hills.

It is very uncomfortable to lose the motor torque while at a big hill without the time to change the bike gear. I should be more wise to program the controller to automatically reduces the torque, and reduce the heat, before the need to actually turn off.

But actually the most annoying was the after regen. cut, it should have some warning as a buzzer beep or something to know the reason for the motor's cut out.

[GM Brazil]

The battery connector is made of brittle plastic and is broken!! I fixed it with some glue, patience and tape but when I pass on rough terrain sometimes the negative pole slides out the battery connector...

They will give me a new connector, for the warranty, but they need to check their suppliers to have a better connector. I do not know how it was braked, one time was ok and the next time I checked was just broke. But nothing hard happened between these checks.