My 2021 TC Max.
Well done Pete! Looks like your making a good job of it. Thanks for sharing.
@LHK I'd imagine they'll take more than the standard limit. Super Soco seem to be pretty cautious with their BMS. The standard charger is under charging a bit too at 83v. They should take 84v if they're CATL cells.
Cheers. Hopefully it will help others if they decide to disassemble the battery if they need to.
I have realised putting the battery back together that, the handle can actually be left attached as can the bottom plate. leaving the handle attached allows it to be used to slide the battery out of it casing.
I am fairly certain the battery is made using CATL cells from looking at the construction. As to maximium discharge I have no idea what it would be but as I am only aiming for 110A maximum (which will be the best part of 8Kw) I am comfortable that the cells will be fine. Yes I will need to charge the battery more often, but that fine if I can get the increase in performance I am aiming for.
The 35mm2 cable is overkill for what I am trying to do, as are the connectors, however they were what I had laying around so made the mod essentially free and being over sized will help to keep any volt drop to a minimum and will keep the cables nice and cool.
Right more progress.
Next I cut the original charge/discharge cables off the connector, but left a small tail on each so I could then solder some 12AWG (4mm2) silicone cable on, I had to do this as with 2AWG (35mm2) installed the stock cable would no longer reach to the positive terminal to allow the battery to be charged through the stock connector. Oh for information the stock cable, in side the battery is 6AWG (16mm2)
I also added an XT60 connector to make removing the lid easier in the future.
Soldered on the matching half of the XT60 to the new charge cables from the battery/BM. I also applied some hot glue to all the battery connections to stop the bolts from backing out due to vibration.
Last step before re-assembly was to drill a hole in the top plate large enough to pass the 35mm2 cable through. The battery was then reinstalled in the casing and the top and bottom plates were installed, don't forget to plug the data connection cable into BMS before sliding the battery into the case 😉.
With top plate back on I made off the ends of the cable, installed the connector and silconed the hole to seal it.
With the battery re-installed in the bike, the next step was to route the rest of 35mm2 from the battery compartment to the controller cut to length, crimp the terminals on the end and having disconnected the stock cables from the controller connect the new ones. To do this I ended up removing the side panels and the front panel.
I already had a 3amp charger installed so I can just plug the bike in and charge it when and where ever I need to.
Whilst the panels were off I also installed a new horn that is a little more manly than the stock wimpy one. I also removed the immobiliser/sound unit cut it open and and disconnected the speaker, which got rid of the start up chimes. then reassembled it and put it back on the bike.
I checked that everything still worked and refitted the panels. I will try and test ride it tommorrow, with the stock settings in the controller to confirm everything still works as it should under load and then I can commence the tuning process.
Thanks again for looking.
I realised that in my first post I mentioned I had replaced the rear shock but kept the stock spring, but didn't go into any detail of why I chose to do this.
Even before purchasing the Max I had seen reports that ride could be harsh. I rode the bike stock for awhile and indeed found the rear suspension to be harsher than I would like.
I had found that I had, had to increse the preload on the spring a fair bit to stop the shock bottoming out, as I weigh around 95Kg. The problem with this was it of course increasd the spring rate, hense the harsh ride.
When I had a spare saturday I took the stock shock off the bike and removed the spring so that I could measure the eye to eye length of the shock see how much travel it had.
I was surprised to find that the 280mm shock has a massive 18mm of stroke before it hits the bumpstop. Ok so that translates into more travel at the rear wheel but still seemed to be very short.
Having used a set of DNM forks on my E-MTB build (same forks as used on a Sur ron) I looked at what rear shocks they make, as they seem to be reasonable quality for not a lot of money. What I settled on was a DNM MK-AR shock with rebound adjustment. I choose to go for a 290mm long shock as this would slightly raise the rear ride height and allow the shock to have a decent amount of sag with weight on. The stroke of the shock is around 65mm.
I used the stock spring, but with a lot less preload, setting the static sag to around 10mm. This has greatly improved the ride quality, I am still fine tuning the rebound setting. The other thing this has done is slightly steepend the head angle making the steering a touch more responsive I also feel that it has moved my weight slightly forward placing it more over the front making the bike feel more planted.
So there you go that's why I swapped out the rear shock 🙂
Hmm, well I have ridden the bike to work for the last couple of days, monday was with the stock settings and it pretty much rode like stock, no surprise there 😆. Today I maxed out the current 110A upped the starting phase current to 45A from 15A, the phase current was already maxed @280A from stock. I also increased the motor RPM from 3000rpm to 4000rpm, i'll comeback to this in a minute.
These settings gave noticably better acceleration but about the same top speed. I was thinking about this at work and realised that the field weaking works at a percentage (86% as standard) of the motor speed so with the speed set to 3000rpm this would be 2580rpm but at 4000rpm this would be 3440rpm and I don't think it will get to this kind of rpm without fieldweakening.
So this evening I have changed the motor rpm to 2900rpm, which should enable the field weakening to start at 2490rpm and be hopefully be more effective.
I also suspect the stock BMS doesn't like the way the battery discharges when set up in bypass as when I switched the bike off this evening it was showing 60% charge. when I went out to change the settings it had dropped to 0% and the BMS had switched off. Putting the battery on charge has switched the BMS back on. I think what has happened is that the cells are discharging unevenly and the BMS is protecting the battery.
I see what tomorrow brings, but have also ordered a new 300A peak BMS so if the problem persists I install that and see what happens.
Ridden the bike a fair bit this week and have nearly refined the settings to where I like them. once I have them where I am happy I will post them up here.
The bms is still shutting down at around 60% battery which has to be due to the bypass. I am getting round this at the moment by charging the battery before @ around 65%, however I now bought a crack unit and a 300A BMS which I will fit next time I have some time off from work.
I have concluded that to get significantly more performance from the bike the stock controller will have to be replaced. I think if I decide to go this route in the future I will try and source a Lingbo HC5XP which is the same physical size as the stock controller but has a higher current and power output. :- HC5XP