The Stormcore app stopped working this week and I had been using it to track rides, monitor stats, etc. (iOS, Stormcore 60D) What are my best alternatives? Should I get a Metr and just roll w/ that? Should I wait for the FreeSk8 remote that should have stats built-in?
The Stormcore has BLE/NRF built in, so maybe there’s an alternative option I’m not aware of?
Abec 11 is a screen printing colour hex
I need a RAL, NCS or BS code
Hi everyone,
I hope this is the right place to post this in.
I could really use some help on my build. I am so lost and confused about the BMS part of things that it is driving me crazy. I got 4 of the following batteries. https://hobbyking.com/en_us/turnigy-high-capacity-4000mah-3s2p-12c-multi-rotor-lipo-pack-w-xt60.html
with the dual fsesc 6.6 from Flipsky and 190kv 6380 Motors from torque boards.
As I understand it from reading and how I would want it. I need a BMS for charging but how do I chose the right BMS with the right charging port and charger? Any tips are appreciated.
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IIRC the general rule for charging batteries is to keep it within 1 C, or how much your battery can discharge in one hour. Since those batteries are rated at 4000 mAh it would be 4a. I’m assuming you’re joining those batteries to make a 12s2p (43.2v @ nominal voltage of 3.6) so 4a might be a good place to start. Though I would wait for someone else to chime in.
Also as a general rule, the lower the current coming from your charger the longer your batteries will last. I would chose a bms based on how fast you want to charge your cells, then look for a charger that fits that spec, then get the charging port that works with the charger. Amazon and aliexpress have plenty of those. You can also always swap out the charge port/charge head.
I think most of the bmses people use can handle up to 10 a (thinking of the Daly BMSs here) which probably would fit the bill for your batteries.
To add to this because @Jilixi asked about charging ports as well: the small white connector on each of those packs is a balance connector. It has one wire leading internally to each of the individual cell groups, +1 for battery negative. Because each of the packs are 4S it’s got 5 wires, these are used for balancing the charge across all cells.
If you want, you could just buy a balance charger and plug each pack in to it individually. It has a basic controller that would balance the cell groups out each time you charge, it’s not super expensive, but it’s a bit of a pain in the ass because you’d kinda need to take the packs out of the board to charge and you’d need to do them all separately. Here’s a link to one that can charge up to 6S packs https://hobbyking.com/en_us/imax-b6ac-v2-professional-balance-charger-discharger.html?queryID=77ad4f55fa03ce2983c3031e0ec651ca&objectID=45235&indexName=hbk_live_magento_en_us_products
A BMS also controls balance of cells, but you usually attach wires from cells groups yourself to one large connector that usually comes with your BMS and plugs into the BMS. My pack is also 12S (so 12 cell groups that need to be balanced) but they’re individual Li-ion cells so I soldered wires to them. For yours, you might need to find an adapter for 3 sets of 4S balance leads to 1set of 12S (people who use LiPos please correct me), or you could VERY CAREFULLY AND MAKING SURE THE LEADS DON’T TOUCH disconnect them and crimp them into a new connector.
BMSs usually start with a port for connecting balance leads (circled in blue), and a bare wire that gets soldered to the battery’s ground.
Depending on whether you use one port for both charging and delivering power to the VESC (called common port BMSs or just common), or have separate ports for each (can’t remember what they’re called, maybe just separate?) they will either have one other wire that goes to the port or one wire for each of the ports. The example above has a negative for the battery and a common negative for both charging and discharging. If this is still very unclear I’ll add wiring diagrams for this.
This is useful because it means instead of having 13 individual wires for each group of cells (+1 for ground) you just have a simple charge port with a positive and negative in one connector. This is preferred for most eskate builds, though as you can tell it’s a little bit messy.
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There’s some detail I left out like how you plan to connect these packs to the VESC in the first place (idk if you have or intend to make a wire that attaches 3 packs in series), but there’s also bypassing BMSs. This isn’t the place to start thinking about but basically:
Charge only BMS: monitors the voltage across the cell groups when being charged. If one group is full it just disconnects that group and runs the current that it would get through a little resistor to stop it overcharging. If the whole pack is full, it disconnects the battery negative from the charger to fully disconnect it. This is why it sits between battery neg and charge port.
Charge and discharge: does all this, plus monitors the voltage on the cell groups while the battery is in use. If a group drops too low and is out of balance while in use, cuts the negative again and breaks the circuit. Probably saves your batteries but could yeet you off the board. Same thing if the pack overall draws too much current, and some fancy ones have a port for a temperature sensor you can use to monitor battery health. If you want to use a BMS like this for extra safety, you need to make sure that it is rated to handle the amount of discharge you want otherwise it will constantly trip, and bigger high current ones are expensive. There’s looots of debate about which to go with.
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Less of a noob question and more of a noob moment:
Didn’t put much thought into the gear ratio when moving from 83mm urethane to 120mm cloudwheels and just got the biggest wheel pulley I could find, 44T in this case. My craptastic no-name motor combined with weighing like 100-110kg (220+ lbs) already meant I have no torque, but now… Well I’m hitting the max current draw from the motors at almost all times, and only drawing like <5A from the battery
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Yep! that one would work fine.
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With a pulley that big you should have pretty decent torque. What are your battery and motor current settings? What size is the motor?
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12S3P battery, each cell rated for 20A continuous but I don’t need that so it’s set to max 40A battery current.
Generic cheapo 5065, VESC detection reckons it can handle 55ish A but I don’t trust it so it’s limited to 40A and I’m consistently hitting that. Might push it higher when I have a replacement around, but when that arrived it’s going into the board too so the load won’t be as high on the bad one
14T motor pulley, 15mm belts, idlers with no tooth skipping
@MysticalDork forgot to reply to your post so editing this in soz
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Hmm, that sounds like it should be fine. If the motor has a temperature sensor, I’d say set the temp limit to something cautious like 90C, and then up the motor current to 55 or 60 and see what happens.
Usually the maximum motor current only lasts as long as it takes to get up to a decent speed (say one third or one half of the maximum or so), then falls off as the battery power limit takes over.
What conditions (speed and load) were those current readings at?
Yeah I think I was running it at 55A until recently but I’ve had a lot of silly stuff the last few weeks. Moved deck and enclosure but only have one fresh set of grip tape so I don’t want to put it on until everything else is final. Upgraded to 12S but was waiting for my BMS and only realised I messed up the order for my 12S charger after the BMS arrived so I haven’t taken it out properly in a week. Didn’t want to run it flat until I had a charger, and don’t want to go too fast or hard without grip tape. Looks like the end is in sight though, I’ll try the more aggressive motor current by the end of the week unless the postman stiffs me
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This is the correct strategy IMHO
You should strongly consider raising your motor max, what is it at? They can generally do a lot more than the autodetection would suggest.
edit: I see it’s a tiny 5065 and Ryan already asked LoL
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could someone explain what amp charger I need for 2x 5s 5000mah lipos, is it 8a? I wanted to use a 42v 2a hoverboard charger but that seems too small?
You should use whatever charge charges your batteries fast enough.
What “fast enough” is for you, is a judgment call you have to make.
That will work (as in, it will charge the batteries and not explode itself or the batteries), but it may not be fast enough. See above.
A general rule of thumb is that charging at 1C (a charge rate matching the capacity of your pack, in your case 5A) will charge your pack from empty to full in a little over an hour. Doubling the charge rate cuts the time roughly in half, and vise versa.
Charging too fast can shorten the lifespan of your cells, so don’t go too crazy - I wouldn’t regularly go over 1 or 1.5 C personally, since I value cell lifespan over speed.
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This isn’t too small, but is likely too cheap to last very long.
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This is what I have come up with so far.
BN 270 hangers , longer motor mount, a new set of motors and wheels.
My idea is to have both set assembled and just disconnect motors and change the whole set up.
BN hangers should fit on TB baseplates since they are both based on caliber trucks?
Is this even a good idea? Will I be able to have the motors fitted underneath the board while going AT or is it just stupid? Otherwise I will have to use longer cables.
yes, because they are VERY easy to short out.
u can still do that, but i would suggest not.
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Thanks for the answer, what if you sealed it with heatshrink after connecting them so no metal is exposed, still short issues?
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