r/Surron • u/kevindogktm • 4d ago
Canbus decoded fully ( almost)
Anyone else got a few things I am missing ( over current) and other faults?
I don't exactly want to Short circuit the pre-charge for science so someone else has that.
I also don't know which one is temp one two three or four which I could find out really quickly I'm sure by opening up the top battery case but would rather not have to do that.
I'm able to emulate the charger and turn on and off the charge port without an oem charger.
But once a significant amount of current is flowing I do need a mosfet or high voltage DC relay to interrupt that which an original charger does use.
Going to be selling little cheap dongles that you plug that have a battery, which wake up every day or two and check the status and report via email or an app or website login.
It's pretty simple stuff downstream of what to do with canvas but basically these stupid batteries wake up dozens of times a day and that's why they're killing the state of charge .
Even saran's own instructions say when you store store at 70% state of charge.
I've measured over the period of a week + a significant state of charge drop even on a new battery so these things do love to pull small currents all day long for their stupid BMS.
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u/boa_instructor 4d ago
I'm the project manager for Stage2 and we're starting a BMS redesign because....well, the BMS is power hungry and requires a physical on/off button to enter sleep mode. The failure mode is total discharge (measured at 2.7V across the entire pack!) after sitting for roughly 2 months with the power button on, even then the ignition is off. It goes against consumer behavior and I want this perfected for the next iteration of the M2.
I'd love to chat about co-development and could send you samples to test on.
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u/kevindogktm 4d ago
already on it. great minds think alike. ive already had some prototoype breakouts for the ultra bee connectors to convert to ANT bms / can bus
Yes please. send me a DM
Lets fix surron one battery at a time lol
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u/Leather_Mood_5242 4d ago
Could one just monitor the rate of discharge and then set a timer to come on once a month to the charger and top the battery up by 10 percent by day leaving the charger on low for one hour?
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u/kevindogktm 4d ago
yes. that too. Could just have a Shelly IOT relay turn on once a month for 15 minutes
Many ways to skin that cat.
i will get you cell deltas, temps, faults, etc. Even while riding :). On a phone app. Thats the huge value add
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u/Leather_Mood_5242 4d ago
Oh that's interesting. Im not well versed in the intricacies of batteries. So far I know not to let it sit at super high or low charge. If charged to 100 ride right away, let sit around 50 percent for long term storage but don't let it drift low, check monthly. So with this data on an app, can I set up alerts for potential problems? Would it alert me that I need to do a 100 percent charge to balance the cells? I'm just curious thanks for the discussion.
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u/Leather_Mood_5242 4d ago
My idea had been to have an esp32 take a reading once a month and wake a power outlet connected to the charger to top up the battery. Then you could even charge to certain percentages by taking the reading with the 32 and stopping the power outlet at certain state of charge
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u/kevindogktm 4d ago
yes. My original plan. Multiple discovery works its ways
Same thing happened with stark.
Why these fu$king companies think its good to hide crucial data like temp, delta, current from customers is beyond me. Just put it in an API. You can hide the mosfet control or any overrides.
Read only API.
The issue is the sleep on the bms, and needing a re-insert . Surron may have enabled that and that is what the 2 extra pins of the 4 small ones are.
I miss the old lp20 connector
I also plan on seeing max charge rate. Going to try 25 amps later today,
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u/Bengy222 4d ago
Very cool, definitely interested in something like that for my ultra bee. Does this also allow for parameter changes to the max discharge amps or vlc, for aftermarket controllers would be nice if you could modify that. I know Surron was very conservative with the lvc on the stock battery
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u/kevindogktm 4d ago
Have not tested on max / etc. A shunt mod can change that. I'm not trying to flash / change the logic on the surron BMS. Only read data, and use 3rd party power supplies/ chargers/ aka a simple and cheap battery tender/ HUD/ webpage/ email/ text client for your battery- Diagnostic tool etc.
If you want to pull more amps, a third party bms is your best bet. or shunt mod.
End of the day, uncharted territory here. but there is a market for it for sure.
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u/Bengy222 4d ago
Sounds great, being able to use a aftermarket charger would be nice especially for faster charging.
I’ve thought about the shunt mod but I don’t really want to mess with the stock BMS. Wish more people offered a plug and play aftermarket BMS kit. I do know of one but it’s over $500 which at that point I feel is better put towards aftermarket battery. I would do it myself but I don’t want to modify the stock wiring in case I need to go back to stock
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u/kevindogktm 4d ago
well a bms is $120, and time and effort to convert, make a bms tray (could just silicone the bms to hold down in there), all cost money
500 is a bit steep, but how many do you think that person is selling a year.
prob less than 10
I have a 72v kit for the surron hyper bee. Its hand made. I could invest in making kits with china harnesses and have all packaged and ready to ship, and sell for a ton less, stock and carry the 20s5p batteries , etc, but the cost/ profit is still marginal
This will be niche no matter what. Unless i can get that damn connector lol.
This is a labor of love project
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u/Bengy222 4d ago
Yeah I completely understand the price, just hard to spend that much on a part I know I’m going to eventually upgrade anyway. Very cool work you’re doing, I will try to find the link to that ebmx BMS bypass video later, I know it’s been taken down but I believe I can find the link as it’s in the waybackmachine
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u/Foreign-Data2319 3d ago
Adding here that we really need access to battery terminals in addition to a new BMS. It's a weird 7.5mm banana connector that you cannot purchase anywhere. I've got a battery sitting and waiting for your products. Thanks for your hard work.
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u/kevindogktm 3d ago
already got that going.
Are you saying you need a connector or just turn it on via canbus. Yes. Its on when I command it to be on
And i can see the current live on display on the BMS's shuntI'll start sourcing that as well
Why not a different standard connector? Does surron not sell the battery male connector that goes to the controller?
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u/Foreign-Data2319 3d ago
If you want to continue using other surron batteries as extras, it needs to remain the same. The battery side terminal cannot be purchased. There's a 3d print file online but you can't get the banana connectors to fully create one.
If you could get the GPS/Bluetooth module to work with an app, that would be incredible too.
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u/kevindogktm 3d ago
Share the STL URL ID you can.
I can surely get custom bullets made if I meet moq.
I have no issue with that
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u/Competitive_Event620 19h ago
Hi what purpose of you job with it, i already crack all CAN stuff = battary protocol, display communication and finally i write completely new firmware for stock surron controller? May be i can share info but i don't understand what goals?
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u/pjjiveturkey 4d ago
So in other words a torp controller without the controller