Quick charger question

Do you have a recommendation for fuse size? I’m guessing an 80a fuse

I also have bot focboxes set at a max for 40a each

No no no no. On the charge port. It’s only going to see a four-amp charger, right? So put like an eight or ten-amp fuse on it.

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ooooo i see i see. thats jsut for if the charger fails or something? cause the charger im picking up tops out at 4a

Not so much that, but as a general safety thing against shorts. What if some idjit decides to mess with your board while you aren’t looking and shorts the pins in the charge port? Depending on the BMS and wiring, you could end up with a fried BMS or cooked wires, or even a fire. With a fuse, you’d get a small pop, a small spark and you can’t charge until you replace the fuse.

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also I’m not sure if it means anything but at first I soldered the the - and + backwards and blew a charging brick but I dont see any damage on the bms and the board still turns on fine so im guessing everything is ok

Wow 4a max charge. Doesn’t this mean you will have very weak brakes?

Doesn’t that mean you have very fast no breaks? :thinking: I know that the values in the data sheet are for constant charging, so I assume no issues when breaking for a short period with 8-10a. But if you for example drive down a longer hill and break for 30sec or longer, wouldn’t the bms cut off which would lead to a total loss of the brakes?

Yup you should test the brakes with that bms. I think it will cut off under hard braking

But than I don’t understand why an esk8 shop sell this configuration :thinking: I mean it even doesn’t make a sense to wire it up for charge only. Ok it makes sense but is too big and too expensive to compair to a d140 for example.

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Could it be a typo? Can’t understand it either why a eskate shop would sell it… I have a HCX-D223V1 aswell but with 20a max charge.

I’m sure it’s a typo because when looking at Bestech site it states 20A max. cont. charge and it’s not an adjustable value so don’t worry. Or is this a special version @JLabs?

The regenerative breaking with BMS is one thing which confuses me from day 1. If the BMS has different ports (P- for discharge, C- for charge) I think the max charging current doesn’t matter for regenerative breaking because the current flow goes back to P- and not C- anyway.

On a BMS with discharge and charge on same port the value for discharge and charge are the same. There are just more FETs on the C- trace (same amount as on P-) and discharge plus charge are connected to C-. There are also BMS available where all is connected to P-. Very confusing for beginner.

I have 5 BMS and all with same port because of my paranoia about a cut off due to breaking. But I’ve heard and read from experienced members that their BMS with different ports never shut off due to hard breaking so I guess it makes no difference. Would be interesting to hear the opinion from an electrical engineer about this case.



I want to increase my regen current settings on my Evo that has that particular BMS and I have not done it yet because I do not know what will happen.

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What’s your actual batt regen settings?

For example I set -15A each vesc so -30A in total. In real life the total batt regen current flow never exceeds about -15A (monitored by app), the highest ever was -17A but usually it’s less even with hard breaking.

Edit: But I have to say that i mainly break at low or mid speed or downhill and usually not at higher speed. When I ride fast then I don’t break, why should I :laughing:?

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Plenty of good reasons… XP

I worry about this too, and although the regen current might be beneficial for a smaller battery, have you guys ever thought of using the Rbreak that maytech makes? Ive been thinking about it, and more and more im ok with the idea of losing regen current, but trading it for always usable breaks

On that particular board I have it set at -10A per Vesc.

So 2 x 10A= 20A which is the BMS’s maximum charge current.

There are lots of times where my total regen current is right at the limit.

Here is an example

What’s that and which esc?

I personally never lost brakes only balance.

Interesting. Seems I’m not breaking hard enough


I would be very interested to see what my currents are with my Trampa (regen set at -40A per vesc :joy:) but I don’t have a metr pro module installed in that one.

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Meaning it should help prevent errors like over voltage, and I would guess some of the amperage as well, I think it was brought up that Regen was lessened.

This is guesswork on my part, but it seems like a product that would be pretty applicable

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I’ve double checked with Build Kit Boards and have been assured that it’s a typo on the sheet and that BMS is indeed a 20a charge max