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.
@drift Yeah for sure will take more than standard but with 35mm2 cable going in and a 175a connector that’s x3 it’s original continuous rating. That’s quite a lot more for cells that have an unknown discharge rate.
As for 84v that’s fairly standard for li-ion anyway not Catl assuming super soco even use high quality like catl. That extra volt in reality will only give a small amount of range and the tiniest bit of rpm gain all be it for a short time.
@lhk I think Pete was just going for a bit of overhead with the wire. Sounds like he's aiming for a reasonably sensible increase in current. I think the standard 7 pin connector is only good for 90A. My connector gets warm after a ride out.
Agreed we don't know the exact source of the cells. The importer here says they are ATL cells. I looked on CATL website, they say 4.2V per cell on the specs. In any case as you say the difference is 0.05V per cell.
The advantage of charging to 84V would be the ability to use any standard 84V charger. With the Soco BMS in place it disconnects the charger before 84V which, according to the charger manuals is not good.
@drift yeah think you are correct. Guess you can’t have too thick a wire only too thin.
Ah that’s interesting that your connector gets warm? Is that with the higher amp 7pin cable? I’m upgrading from the older tc max with the 60a controller and lower amp 6 pin connector. Im replacing for a 7pin so possibly still under sized for my 100a target?! Will possibly need to keep an eye on that. Maybe just good for bursts and not continuous.
I have heard charging to the full 84v is good for balancing etc. I use standard chargers on the original battery too though, if you open the charger case there a pot inside that you can adjust the output voltage with so I just set mine down to 83v and then it works fine with stock battery.
@lhk Mines the 7 pin connector and it gets a bit warm. But it only gets warm if I ride it flat out the whole journey. I should think 100A bursts will be ok.
Good call on adjusting the charger. Which one do you have? Mine doesn't have an adjustment pot.
@drift great thanks for the feedback that’s good to know.
I use a fairly basic charger for slow charging, max 3a and have another capable of up to 12a which is handy when I’m in a rush.
iv attached a photo of the slow charger where you can see the adjustment pots inside where you can adjust the current, voltage and cut off current. It’s a handy little charger.
@drift excellent, just double check voltage and polarity before you hook it up to your battery just to be sure. And you need to power up the charger before plugging it in otherwise you get a small spark at the connector due to the capacitors charging
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.
Pete.
@petesscalefabshop 110a should hopefully make a noticeable difference. I’m aiming for 100a to start and just in the process of installing a temp sensor into the motor so I can monitor its internal temperature and see how far I can push it. The motor seems like a high quality design not far off a QS 138 design. I think maybe the weak point will be the belt, but time will tell. I just keep a spare in the box.
the horn looks good is it noticeably louder? you have details on the one you used?
The horn is a Low tone Hella unit I got from amazon :- https://www.amazon.co.uk/gp/product/B00H8QOLNG/ref=ppx_yo_dt_b_asin_title_o01_s01?ie=UTF8&psc=1
It is noticeably louder and also has a deeper tone which I prefer.
@petesscalefabshop Looking good mate. I thought about getting rid of the stupid music box but decided to keep it for the alarm. I've seen on youtube the normal TC model doesn't play a tune on start up. The module looks identical. I wonder if they're interchangeable.
@petesscalefabshop Why you didn't use the power cable also to charge battery?
@tonyb, I didn't want to use the power cable to charge as it bypasses the BMS and therfore the cells would not get balanced during the charging process.
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.
@petesscalefabshop that sounds about right regarding your field weakening theory. Iv got the max natural speed of the motor down as 2800rpm before it needs field weakening to increase it. Hopefully your adjustments will fix it.
So you planning on replacing the BMS completely and now using the discharge port? You can get the hack module with the ant BMS so that the can bus still sends the soc info to the screen and app which is useful.
@lhk Interesting that you have 2800rpm and the controller was set to 3000rpm as standard.
Reducing the motor rpm to 2900rpm made a noticable difference as I gained around 5mph top speed, with the weaking current set to 25amps.
This evening I have reduced the motor rpm to 2800rpm and increased the weaking current to 50amps.
I will report back with my findings tomorrow.
If I replace the BMS, I will continue to use the new cables and connector for discharge just not bypassing the BMS and the stock connector for charging.
@petesscalefabshop I guess that figure moves up and down depending on the soc battery voltage but that’s great you got an extra 5mph out. That’s a neat improvement. I imagine that extra 25a will make a difference again too
@lhk Yeah that sounds likely.
So the changes made last night have again increased performance, I can't say by how much as I didn't get a clear run either going to or from work today, however what I found was that I could acheive the same speed as yesterday but without having to peg the throttle, which was a nice surprise.
I should point out that the piece of road I use as a test is about a mile long and is a slight uphill going to work and obviously a slight downhill coming home. Stock the best I could get was 50mph going to work and 55mph coming home and it would take most of the mile to get to this speed with the throttle pegged wide open.
Now I can get to the same speed in about a 1/3rd of the mile and can now maintain speed with about 3/4 throttle.
Hopefully over the next couple of days I get a chance to find out what it does flat out 😀
@petesscalefabshop that sounds very promising. Are you still running stock tyres or have you swapped out for a higher quality brand? I swapped mine out for some Pirelli angel city and they felt much nicer at higher speeds
Have you thought about putting in a shunt for a coulomb meter so you can see exactly how may amps your drawing at those speeds?
Definitely interested to see what you max out at.
@lhk Yes currently still on the stock tires, I have been looking at getting some better ones and possibly a slightly larger rear at the same time.
I have a shunt and meter ready to go in, I ran out of 35mm2 x M6 terminals when making the new cables so haven't been able to wire it in yet.
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
@petesscalefabshop woodniu on AliExpress does direct controller replacements of higher power which could work well for you.
im running one of their battery’s and its real nice. Possibly the same person you got your crack module from?
@lhk It is where I got the crack module from.
I actually have one of their controllers already, it's dead but thats another story, The main issue I have with it is that it can't be mounted in the original controllers position as it's a different size and shape, and it also can't be mounted in the position it is designed to fit without extending the motor wires.
'the other story' Oh and if you accidentally plug the interface connector, which fits the socket either way round, in the wrong way round it fries something in side and stops working hence having a dead one. I might get round to taking it apart and seeing what I killed at some point.
@petesscalefabshop ah ok What a nightmare. Seems like a huge design flaw in the connector. Mine was the old design where it’s mounted up front but I made the mistake of connecting up the data cable before the main negative and the capacitor charging fried the negative feeds in the data connector. Hence now the sabvoton instead.
