Begode EX30 charge board bypass mod (also Master etc)

[Planemo]

First off, thanks to Roger Hajili (I can't find his username in the forum to tag him!) for initially coming up with the idea and @Marty Backe for spreading the idea to the wider public. I just wanted to share what is involved in bypassing the EX30 board. This will also apply to some Masters too but I cannot confirm which models as I have only done this to my EX30 board.

Also thanks to @Cerbera for supplying the image below which I have used to add my poor drawing skills to.

I wanted to create this thread because I couldn't find a guide or video anywhere on how to do this. Roger did a good YT video on how to mod the Extreme board but the layout is very different to these earlier boards.

I used 14AWG silicone sheathed wire which is the same rating and wire type as the stock main feed to the board. You could do this mod permanently by simply running a single link between the two solder points or, as I did, run 2 wires out of the control box to a switch.

The solder points/wire are quite large and will require a decent soldering iron. It goes without saying that there are high voltages involved at up to 15A and so your joints need to be good and sound.

NOTE: There are risks with this mod:

1. It has not been confirmed, but it is believed that the mod will remove the ability for the packs to cut charging if and when a cell goes beyond 4.25v. In an ideal world this should not happen because the BMS's (which are unaffected by this mod) should bleed any high cell off as normal but should there be a situation where it can't...charging will continue.

2. Should your charger be set too high/have an internal fault or anything else then as per above, charging will not be cut if input voltage goes beyond 134.4v. Therefore, extreme caution should be used if you are using a Roger charger or any charger that is able to go beyond 134.4v.

This mod still has limits. There is a 15A fuse on the charge board which is not bypassed so I would suggest a max charge of 14~14.5A. The main benefits of this mod are:

1. Ability to use a high amp charge (over @ 8A) without the board cutting out @ 75% charge as has been reported by many riders.

2. Ability to go to a full 134.4v charge (most users report up to 133.5v as max stock). This should help get a proper balance to the packs as the BMS's are passive and therefore only balance in the CV stage.

In any event I would strongly suggest that any wheel with this mod activated is not left unattended.

The pic below shows where I sent the 2 lines off to a switch. There is a handy cut-out in the corner of the board which provides enough room to allow 2x 14AWG wires to be brought out of the control box to an area of your choice for a switch. I went with a section on my Grizzla rear bumpers because it suited and I already had a switch for my LED's on the other side. For the switch itself, I used a SPST splashproof type, rated 240v AC at 6A. This is technically undersized for the job but the rating is based on the switching ability more so than the current handling so I was happy to use it but I WON'T be switching it under load, only prior to/after the charger is connected.

Note: Due to the thickness of 14AWG, one wire will need to be routed (as per the pic) and taped just enough to hold it away from the 4 chips that sit most proud from the board. Things get a bit tight on clearance otherwise and you really don't want to be trapping/applying pressure to wires.

Finally, the aim of this is to simply make a bridge between the negative on the charge port and the negative on the main output to the board. It's always worth doing a check on your particular board just to make sure you have the right solder locations.

[Marty Backe]

Nice.

I only have this mod on my Master Pro so I can get the most out of it. I also have modded firmware that let's me ride down to 2.9-volts (only needed a couple of times - but it's nice to have just-in-case) which will cause the BMS alarms to trigger. Without this bypass, the BMS alarm trigger would prevent me from charging the battery pack. So yes, this mod does disable the ability of the BMS to disable charging.

Roger (and others) also usually remove/change the fuse to allow charging at much higher levels

I've tagged @roghaj for you 

[Planemo]

13 hours ago, Marty Backe said:

I only have this mod on my Master Pro so I can get the most out of it. I also have modded firmware that let's me ride down to 2.9-volts (only needed a couple of times - but it's nice to have just-in-case) which will cause the BMS alarms to trigger. Without this bypass, the BMS alarm trigger would prevent me from charging the battery pack. So yes, this mod does disable the ability of the BMS to disable charging.

Cheers for that info bud, I'm never brave enough to go down to less than 20% but good to know.

13 hours ago, Marty Backe said:

Roger (and others) also usually remove/change the fuse to allow charging at much higher levels

Good shout, I won't need to go over 14.5A but I can see why some might. At 6P even the 'lowly' 50E cells take 14.7A at the 'standard' charge of 0.5C and nearly 30A at max (1C). Bypassing the fuse or indeed changing it for say a 20A would be an easy job given it's ease of access. Of course I will add the caveat that I don't know how much current the BMS's can take though.

13 hours ago, Marty Backe said:

I've tagged @roghaj for you 

Cheers, I did do a search using @rog and that tag doesn't come up for me!