Chinese ESC + Charge Only BMS

So, Meepo 3.0 ER’s use a 40T 10S2P pack. The 40T is capable of 70A drain, I want this to be accessible if the rider decides to switch to a VESC/unity. Which means the BMS needs to also be a high drain rate.

However, I have not managed to find a BMS that is ~40mm wide, to would fit in the enclosure, anywhere near that drain rate. The one linked below may work, 60A cont, but I can’t exactly tell the size and I still think it’s to wide.


I also like the dickyho waterproof ones, but the 60A version is definitely to large to fit in the meepo enclosure.

Which brings me to my question, can the Meepo, lingyi, ESC properly function with a charge only BMS and not overdraw and damage the cells? I’m pretty confident it will, but just wanted to get some other opinions so I don’t burn a board to the ground.

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On the lingo escs I have there is a low voltage cutoff at 3.1v per cell so you should be good!

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I will be more concerned about the regen , im pretty sure the value of regen of this esc its pretty high …
i have the same dilemma, let me know what you find about this :slight_smile: @A13XR3

Could implement a rheostatic brake if regen is too high?

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I assumed they had to have a low voltage cutoff since even my meepo 1.0 would turn itself off after the battery voltage was low enough, and to force the BMS to be the only method of cutting the board off seems foolish since it would likely be a harsh cut. Speaking of, any input as to if the ESC has a soft voltage cutoff or not?

The regen question is an interesting one, but regen is pretty inefficient, so I’m not sure how much more than 30A they could be pushing back to the battery even under heavy braking. I’ll have to do more research into this bit and see what amps people are peaking at during regen in their data log’s.

Trying to implement anything else basically defeats the purpose. I need it to drop into an existing enclosure and be worry free. Either because I’m confident in bypassing the BMS or because I’ve found one that fits.

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make sure the nickel strips they use can support 30a+
they might be single strips…

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Long term update to this, Meepo V3 and V2.5 ESC’s function completely normally with a discharge bypassed BMS as would be expected. With about 100 cycles between myself and a friend (mostly him) I fell confident the low voltage cutoff is fully and properly implemented in Meepo LIYing ESC’s, at about 31V. I didn’t check the cutoff voltage of the pack after the first 10 or so full drains, but it never ended below 30.7V.

As for pulling 60A from them, I haven’t built either of the packs with enough nickel to support it because I haven’t needed to. When someone comes along and wants to eventually switch to a VESC I’ll be able to cross that bridge and find out, but I use enough nickel to pull 40A all day and may pickup a smart BMS one day to track how many amps the pack is discharging from the Meepo ESC just cuz.

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the meepo v3 ESC is 30a max total right? (for both motors)

They’re on V6.0 of the ESC’s so I’m now not entirely sure what ESC’s I was testing on. The V3 board has a V5 esc. The V2.5 was from an og NLS, not the pro. So I guess it was ESC V4?

Anyhow they say the V5 and V6 ESC’s are 32A, which I assume means 32A per motor. No idea what the battery draw is, also why I might get the smart BMS to track how much it’s pulling, I’d want to get myself a V6 meepo ESC tho. Dont feel like buying a whole meepo for a new set of hubs and the ESC. Wonder if Kieran would just give me the info…