Lurkin
100 kW
^true.
BUT =-DIY at it's best!
BUT =-DIY at it's best!
MXUS 5T - 4 Banger Build
- Thread starter Jestronix
- Start date
Thumb throttle tested, half grip tested now for the full grip.
I like the volt meter, probably the best fuel guage I have.
Thumb = safer .... But I didn't have nice throttle control over the bumps, jerky acceleration was the result.
Half grip = better control , great for holding the same revs too as u can grip the bar and the half grip. Down side, all my weight on outside of my hand, sore and less safe as I didn't have full grip.
I like the volt meter, probably the best fuel guage I have.
Thumb = safer .... But I didn't have nice throttle control over the bumps, jerky acceleration was the result.
Half grip = better control , great for holding the same revs too as u can grip the bar and the half grip. Down side, all my weight on outside of my hand, sore and less safe as I didn't have full grip.
markz
100 TW
I like the volt meter, where did you buy that?
markz
100 TW
Thanks, it was the very first one lol
http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR4.TRC2.A0.H0.Xebike+throttl.TRS0&_nkw=ebike+throttle&_sacat=0
Good stuff!
http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR4.TRC2.A0.H0.Xebike+throttl.TRS0&_nkw=ebike+throttle&_sacat=0
Good stuff!
markz said:
Was a little scary this morning , i kept looking at the volts! under full wot to see how far down she was dipping. 60amps @70v was dropping to 64v ,, 3.4 per cell. .4v sag. according to my ebay trusty meter though. would this be acceptable sag ?
nutnspecial
10 MW
Sag under 3.5v /cell was too hard on mine, at least the questionable cells. The decent packs didn't seem to mind.
Idk if you can trim the halfgrip down, but I really like a nice short halftwist. Mines like 1/3, and it could be shorter. The right hand got a little tired with hard riding at first, but it got stronger eventually. Also, on custom displays, there are 2-4$ volt/ammeters from china there are a nice addition to the more plainjain throttles/setups.
Jest, are you considering getting the frame fixed? Aluminum is far more rigid than steel, but can only be 'loaded' so many times before breakage. Nothing wrong with AL, but it has more of an expiration date. A fix on the weak spots could lead to 100% increase in life, but if a modified bike makes it way past the natural obsolescence, one would want to be extra careful of more critical areas, such as headtube etc.
Idk if you can trim the halfgrip down, but I really like a nice short halftwist. Mines like 1/3, and it could be shorter. The right hand got a little tired with hard riding at first, but it got stronger eventually. Also, on custom displays, there are 2-4$ volt/ammeters from china there are a nice addition to the more plainjain throttles/setups.
Jest, are you considering getting the frame fixed? Aluminum is far more rigid than steel, but can only be 'loaded' so many times before breakage. Nothing wrong with AL, but it has more of an expiration date. A fix on the weak spots could lead to 100% increase in life, but if a modified bike makes it way past the natural obsolescence, one would want to be extra careful of more critical areas, such as headtube etc.
Had a good test ride today, charged my pack to 4.1 per cell and down to 3.6 , sag was to about 3.5. Charging to 4.1 instead of 4.2 was about 8% difference in storage but easier on cells. I may need to beef up my connectors and wires, 60amps thru XT 60 connectors, time for XT 90.
I'm thinking I might take the bike in and get it welded, depending on cost, it's not the main structure of the fram more the rear suspension arm link on one side. I'm keeping an eye on it for now, as much as one can.
I'm thinking I might take the bike in and get it welded, depending on cost, it's not the main structure of the fram more the rear suspension arm link on one side. I'm keeping an eye on it for now, as much as one can.
nutnspecial
10 MW
I'm happy with 5.5mm bullets for my 71 amps. Cheap and not hard to do with a torch.
Because of the frame area in question, it's a good canditate for a fix without worrying about reheattreating and aging the area (plus it may be 7005 al, which doesn't require treating to begin with). I spent the 150 on an al 'spool'gun for the mig welder this year, and although the welds look like hell, they can be cleaned up, and it's been working great for the structural mods (actually whole new mounts) I've made on two aluminum bht motors- no treating or aging, and they see a fair amount of torque.
A hobbist or small shop could prob fix it fairly cheaply, and it should be well worthwhile. I'll certainly consider it if/when my 16yo al frame develops its potential chink into a hazard.
I like the ride!
Have fun!
Because of the frame area in question, it's a good canditate for a fix without worrying about reheattreating and aging the area (plus it may be 7005 al, which doesn't require treating to begin with). I spent the 150 on an al 'spool'gun for the mig welder this year, and although the welds look like hell, they can be cleaned up, and it's been working great for the structural mods (actually whole new mounts) I've made on two aluminum bht motors- no treating or aging, and they see a fair amount of torque.
A hobbist or small shop could prob fix it fairly cheaply, and it should be well worthwhile. I'll certainly consider it if/when my 16yo al frame develops its potential chink into a hazard.
I like the ride!
Have fun!
Yep its 7005 so no heat treating needed. Im pretty sure all this happened the other week, full speed through the grass and hit a tree root! i was sure i was gonna get a puncture, but id say this is when those cracks showed up. Sounds like a good idea, im gunna get it fixed up and maybe get them to beef up the existing stuff a tad. chop shop style, not interested in looks 
Decided it was time to house my batteries in something stronger and fireproof. I plan on capping the ends with just a small vent. Hoping for more heat transfer when the batteries warm up.
50mm x 50mm aluminum square extrusions. Housing two 4s 6600 packs, thinking of maybe running 24s and charging to 4v for a 96v pack. peak charge of 4v and down to 3v , hopefully this will stretch my lipo life a bit further.
50mm x 50mm aluminum square extrusions. Housing two 4s 6600 packs, thinking of maybe running 24s and charging to 4v for a 96v pack. peak charge of 4v and down to 3v , hopefully this will stretch my lipo life a bit further.
Lurkin
100 kW
Random question - is lipo capable of melting aluminium when it goes off?
Lurkin said:
exactly what i was thinking, 660c is the melting point, lipo burns at double this, however this would be internal flashpoint temps. maybe i could look at lining it a fireproof material. also very interested in how starving a lipo effects the burn rate and temps. if i can seal it well enough i may never see a fire.
This is a good read, oxygen is produced at the later stages, the key is keeping temps down by the looks,
The first stage is the breakdown of the thin passivating SEI layer on the anode, due to overheating or physical penetration. The initial overheating may be caused by excessive currents, overcharging or high external ambient temperature.The breakdown of the SEI layer starts at the relatively low temperature of 80ºC and once this layer is breached the electrolyte reacts with the carbon anode just as it did during the formation process but at a higher, uncontrolled, temperature. This is an exothermal reaction which drives the temperature up still further.
(Lithium Titanate anodes do not depend on an SEI layer and hence can be used at higher rates.)
As the temperature builds up, heat from anode reaction causes the breakdown of the organic solvents used in the electrolyte releasing flammable hydrocarbon gases (Ethane, Methane and others) but no Oxygen. This typically starts at 110 ºC but with some electrolytes it can be as as low as 70ºC. The gas generation due to the breakdown of the electrolyte causes pressure to build up inside the cell. Although the temperature increases to beyond the flashpoint of the gases released by the electrolyte the gases do not burn because there is no free Oxygen in the cell to sustain a fire.
The cells are normally fitted with a safety vent which allows the controlled release of the gases to relieve the internal pressure in the cell avoiding the possibility of an uncontrolled rupture of the cell - otherwise known as an explosion or more euphemistically "rapid disassembly" of the cell. Once the hot gases are released to the atmosphere they can of course burn in the air.
At around 135 ºC the polymer separator melts, allowing the short circuits between the electrodes.
Eventually heat from the electrolyte breakdown causes breakdown of the metal oxide cathode material releasing Oxygen which enables burning of both the electrolyte and the gases inside the cell.
The breakdown of the cathode is also highly exothermic sending the temperature and pressure even higher. The cathode breakdown starts at around 200 ºC for Lithium Cobalt Oxide cells but at higher temperatures for other cathode chemistries.
By this time the pressure is also extremely high and it's time to run for the door.
The first stage is the breakdown of the thin passivating SEI layer on the anode, due to overheating or physical penetration. The initial overheating may be caused by excessive currents, overcharging or high external ambient temperature.The breakdown of the SEI layer starts at the relatively low temperature of 80ºC and once this layer is breached the electrolyte reacts with the carbon anode just as it did during the formation process but at a higher, uncontrolled, temperature. This is an exothermal reaction which drives the temperature up still further.
(Lithium Titanate anodes do not depend on an SEI layer and hence can be used at higher rates.)
As the temperature builds up, heat from anode reaction causes the breakdown of the organic solvents used in the electrolyte releasing flammable hydrocarbon gases (Ethane, Methane and others) but no Oxygen. This typically starts at 110 ºC but with some electrolytes it can be as as low as 70ºC. The gas generation due to the breakdown of the electrolyte causes pressure to build up inside the cell. Although the temperature increases to beyond the flashpoint of the gases released by the electrolyte the gases do not burn because there is no free Oxygen in the cell to sustain a fire.
The cells are normally fitted with a safety vent which allows the controlled release of the gases to relieve the internal pressure in the cell avoiding the possibility of an uncontrolled rupture of the cell - otherwise known as an explosion or more euphemistically "rapid disassembly" of the cell. Once the hot gases are released to the atmosphere they can of course burn in the air.
At around 135 ºC the polymer separator melts, allowing the short circuits between the electrodes.
Eventually heat from the electrolyte breakdown causes breakdown of the metal oxide cathode material releasing Oxygen which enables burning of both the electrolyte and the gases inside the cell.
The breakdown of the cathode is also highly exothermic sending the temperature and pressure even higher. The cathode breakdown starts at around 200 ºC for Lithium Cobalt Oxide cells but at higher temperatures for other cathode chemistries.
By this time the pressure is also extremely high and it's time to run for the door.
Samd
10 MW
Speaking from experience, when encapsulated in a full frame it doesnt melt aluminium on excessive discharge. Overcharge may be different.
A few back I deliverately overdischarged some old 20c batteries nside one of my older custom frames - it couldnt get hot enough for thermal runaway.. The top tube got pretty warm, but that's it.
One of these:
https://endless-sphere.com/forums/viewtopic.php?f=31&t=56712&start=25#p927554
Hey Jestronix, are you still running that controller in reverse mode or forward? I am wondering if you have a false phase combo, sag seems a bit high.
Try this
https://endless-sphere.com/w/index.php/Determining_the_Wiring_for_a_Brushless_Motor
A few back I deliverately overdischarged some old 20c batteries nside one of my older custom frames - it couldnt get hot enough for thermal runaway.. The top tube got pretty warm, but that's it.
One of these:
https://endless-sphere.com/forums/viewtopic.php?f=31&t=56712&start=25#p927554
Hey Jestronix, are you still running that controller in reverse mode or forward? I am wondering if you have a false phase combo, sag seems a bit high.
Try this
https://endless-sphere.com/w/index.php/Determining_the_Wiring_for_a_Brushless_Motor
Hey Sam interesting , ill have to try and over charge scenario.
Yep still running backwards, I currently have the controller off as I'm going to mount batteries in its place. So haven't had a chance to change the phase wires as you said.
Just waiting on the 100v 80a controller to roll in
Yep still running backwards, I currently have the controller off as I'm going to mount batteries in its place. So haven't had a chance to change the phase wires as you said.
Just waiting on the 100v 80a controller to roll in
Samd
10 MW
Yep, can't wait for the 8kw mothers too
In the bottom right you can see a box that says to exchange yellow/blue sensor wires and yellow/green phase wires. I'm gonna give it a go myself the first time I can. I've not had to exchange hall wires before....
In the bottom right you can see a box that says to exchange yellow/blue sensor wires and yellow/green phase wires. I'm gonna give it a go myself the first time I can. I've not had to exchange hall wires before....
Samd
10 MW
(Bloody Golden Week)
Finally mounted the batteries under the front bar , along with the controller. I've tried to neaten up the install this time round, but my main reason was to shift the weight to the front and lower, along with the safer protected battery tubes.
A test ride today was promising, I really noticed the effect of lowering the weight and moving it forward.
I also bought some 20c single 5ah cells to fit into my 50x50 aluminium extrusions.
I can fit 5 cells in, I will add some spacers to get a nice snug fit. I'm contemplating on hooking them up in parallel for 25ah at 18 or 20s , this should give me some good range and cell longevity by shallower charging and discharge. Plus pulling max of about 3c, which should really help. but not cheap. $800 AUD. $660 for 3x 20ah multistars is also an option, but can't make a nice fit for theses.
A test ride today was promising, I really noticed the effect of lowering the weight and moving it forward.
I also bought some 20c single 5ah cells to fit into my 50x50 aluminium extrusions.
I can fit 5 cells in, I will add some spacers to get a nice snug fit. I'm contemplating on hooking them up in parallel for 25ah at 18 or 20s , this should give me some good range and cell longevity by shallower charging and discharge. Plus pulling max of about 3c, which should really help. but not cheap. $800 AUD. $660 for 3x 20ah multistars is also an option, but can't make a nice fit for theses.
Samd
10 MW
Nice work on the tube.
FWIW Bunnings sells a 90x50mm downpipe that works ok too. Think I still have some 3d printed ends for it somewhere.
https://endless-sphere.com/forums/viewtopic.php?f=6&t=15567#p394735
FWIW Bunnings sells a 90x50mm downpipe that works ok too. Think I still have some 3d printed ends for it somewhere.
https://endless-sphere.com/forums/viewtopic.php?f=6&t=15567#p394735
90x50 darn, missed that one, I haven't been able to find that one. I should take a look around at Masters too. Whilst on the subject I think its time to find a local welder that can do me up some custom battery boxes. Drives the cost up, but would be nice to have a fully customized setup. Next thing we need to do is reduce these controller box sizes, they are huge. One thing i have noticed is the batteries don't get warm anymore, the aluminum must be acting as a heat sink. The fact they do get warm is an issue, pushing 10c max out of them on full WOT.
Samd
10 MW
Full metal frame with the controller removed from casing and heatsinked directly to frame inside is where we are mostly at 3 or 4 years later...
