Those batteries are each made up of two sets of two cells in parallel then together in series for 2s. The output is still the same 2s 5000mah.
Ok. So what’s the point of having 2S2P then? (In this situation).
I recommend using 2s1p Lipos. that way you are balancing every cell individually. With a 2s2p Lipo, you would be balancing 2 cell groups as 1cell. The 2s2p Lipo is made of 4 2500mah cells in parallel and in series. (personally, I would not recommend these for any application) $125 for 5 2s1p 5000/60-120c packs might seem a little pricey but you get what you pay for. They are high quality packs with low internal resistance. Because of this and their high amp capability, they will be less prone to overheating like some cheaper lipos. To answer your question, higher mah would not affect the bms as long as you wind up with 10s voltage
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Couldn’t have said it any better than Namasaki. This thread is an inspiration for me on a future build.
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This setup will work with five 2s lipos or two 5s Lipos. It’s basically the same thing though because you have more balance wires coming for each pack, you need to be all the more careful and find out using a volt meter which cell each of the colored balance wires goes to. Red is always the last cell in each pack. The black balance wire is ground and is not needed with the Bestech BMS. As you can see by the diagram, The pack that supplies the Black power wire to the system is pack 1 Cells 1,2,3,4,5 and the pack that supplies the Red power wire is pack 2 Cells 6,7,8,9,10 Just connect everything correctly and double check it before turning the power on and it will be fine.
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Thanks for all the schematics, I learned allot! I ordered the same BMS but I have an anti spark as well. Now I read somewhere that isn’t needed with this BMS cause you it has an e-switch. But I’d rather use my anti spark, just to be save. What do I do with the e switch wires?
Drawn up a wiring scheme, hope you can help out what to do with the e switch wires and if everything is in the correct place.
Might want to add some leds as well, what’s the best place to connect those?
(the anti spark got a switch, but forgot to draw it)
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The built in E-switch has to be on during discharge and charge as well. The E- switch is also needed to reset the BMS in the event that one of its protection circuits is activated and shuts the system down. There is no easy way to bypass using the built in switch. You can use an anti spark switch in addition if you want, you’ll have to have 2 switches then. I really wouldn’t recomend it. Because adding the anti spark switch means more connections which means more resistance across the system and those external anti spark switches are prone to failure and could leave you stranded. The built in E-switch eliminates the spark issue anyway and it has been very reliable for me since last summer when I started using it.
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I would also recommend getting a couple 5s extension cables, plug those into your batteries, cut the plug off the other end of the extension and wire that to your BMS balance cables. Then you can quickly disconnect your batteries from the BMS for inspection and maintenance. Keep your hobby balance charger for maintenance in case you ever need to replace a pack because you’ll need to manually balance it with the existing pack. The BMS will keep your packs in balance during charge and discharge cycles but they need to be balanced manually at first because the BMS won’t be able to balance them if they are too far out of balance.
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One more thing. When using five 2s packs, the balance wiring is very simple but when using two 5s packs, it can be easy to make a mistake with the balance wires and their correct order. If you get it wrong, you will fry the BMS. So use a voltage meter to determine which cell each wire comes from and double check to make sure it’s wired correctly before connecting the main power wires from the battery and powering up the system.
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Aha, can I attach a led switch to the eswitch?
Thanks for the extension cable tip. I was hoping for the BMS to do all the dirty work, but some manual won’t be too bad.
Any recommendations on the charger or any 42v 5a from aliexpress will do?
And sorry for being such a noob, but how can I check if the balance wires are correct? What makes them correct?
Thanks for all the help, don’t want to blow up my BMS (:
No need to apologize for being a noob. All of us where noobs starting out. that’s a really nice JST-XH chart. It looks correct but I would still double check my balance wires with a voltage meter. This BMS does not use the Black ground balance wire from the Lipos as illustrated in my diagram. The BMS balance jack is numbered on the bottom side of the PCB. My updated diagram show the bms layout as it is on the real thing.
There is one more important point that I almost forgot to mention: These modules are static sensitive so you need to have some type of static protection before you open the bag and remove them. I use these wireless wrist bands. They seem to work well. They absorb any static charge that is on your body.
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I have a lot of experience with RC cars but I am new to eskate. After reading a lot I have the feeling that 10s 5000mah lipo performs as good as 10s3p liion and almost like 10s4p.
That shouldn’t be that way because 10s4p with Samsung 25NR is twice the mah but in practice this looks true… Anyone else have the same impression???
Those are pretty good, I have one similar that I got from Battery Supports. It charges the pack fairly quick but cant quite charge the pack fully to 42v. It does get the pack up to 41.8 or 41.9 before getting the green light. The only other option is to use an Adjustable CC/CV lab power supply. Which is what I use. I like to get my pack fully charged for maximum performance and range and I am less concerned about their longevity.
Well, If you buy quality Lipos with high C rating then Li-ions can not compare is performance per pound. Example: My packs are 10s 5000mah 60/120c Thats a rating of 300a continuous and 600a peak A li-ion 10s3p is only 60a continuous a 10s4p is only 80a continous So, some may ask why would you need a 300a battery? The answer is VOLTAGE SAG. With a 300a battery, there minimum voltage sag under demanding conditions. With a 60-80a battery you will see much more sag under the same conditions. On top of that, the 300a Lipo pack is smaller and lighter than the 80a Li-ion pack. Some feel that Lipos are too hazardous and I for one have said as much. But recently I am finding that Li-ion cells can be just as hazardous.
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Yes you can but the bms will not power the light. You will need a volt/ohm meter to test continuity and find the 2 poles that connect when the button is on and connect the E-switch wires to those 2 poles. then find the 2 poles that energize the light when the switch is on and connect those to pos and neg 5v source. I used an open channel on my receiver to power the light on my switch. It is ultimately powered by the 5v coming for the Vesc.
Adding to @Namasaki here, Performance is relative. Are you measuring performance with range, power output, efficiency, or something else???
If we talk about range, the 10S4P is better as you have more energy. 360Wh vs 185Wh in the LiPo If we talk about power output, the 10S 5000mAh LiPo is better as they are designed to run at high power conditions, you’ll see this in the power ratings. (18650 cells rated between 1.5C-10C, while LiPos are rated between 25C-120C) The LiPo is smaller (8.4% smaller in volume) and lighter (17.2% in weight), but that is only because it has about half the energy than the 10S4P pack. If you compare two packs with identical energy the LiPo will be much heavier and bigger.
25R cells are pretty terrible cells in my opinion, the only good thing about them is that they’re cheap and really they’re not that cheap…
I suggest you use 30Q cells.
- They have 3000mAh which means a 10S4P pack will have 432Wh, which is 20% more than the 25R and 134% more than LiPo.
- They have much lower voltage sag than 25Rs which means you can push your board as much as you want without it cutting out on you.
- Can be found under $4 per cell.
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I am running the same battery pack but a single 6374 and a vedder e-switch+ big hobby charger. I am wondering what kind of range you are getting on a charge, and how long it takes the BMS to charge from empty to full? Is it charging at like 2A?