heck yes, I would love one if those. I saw that when you posted in the battery builder club thread and suddenly believe in true love
buuuut… an Imax B6AC is 30 sheckles and works fiiiiine…lol
I went with the split pack method because of how easy and cheap it is to get 1-6s chargers
also, I had to find a connector that was less than the thickness of the enclosure so the smaller plug fit better
Did that on my board with a GX20, it’s not too hard to solder as long as you start with the middle pins, TS80 with the pointy tip works great for that.
Wanted to eliminate a failure point from the board, but ironically, my D140 arrived semi-dead. 
Round of applause for Bestech QC everyone, not 1 mistake in 10 years.
Update with salvaged pics (first post)
Also, I lurked around and found @visnu777 's beautiful builds
Grunstern
and Blutstern
Question for @visnu777: Do you have the same charging cable for the two boards? Same charger? I’d love to hear more about your experience with this type of charging since you’ve been at this longer 
What balance charger are you using?
Bump. Charging one side at a time doesn’t sound terrible tbh
Yeah I mean, I’d attach balance leads (jst) for a balancing board, but personally I don’t even plan to keep a charging/discharging BMS on my setup. It’s a waste of space and another failure point especially if you’re letting it handle discharge current, and none of the chicom BMSs are up to the discharge amperage we’re running, long term at least.
I always charge my packs with CC/CV power supplies externally. Balance as needed, separately. You can get some pretty large buck, or boost modules in the 1500w range (Chinese 1500w, so lets say 1000w to be safe) for around $25 all day long. Monitor it with a DMM until you know it’s safe, and worst case, use a high voltage, regulated bench PSU to top up. All that may sound convoluted, but trusting a Chinese BMS with all aspects of your pack’s management and safety sounds fuckin insane to me.
Balancing board like this?
I’m doing this for my demonseed battery. To use the dual 12s balance charger for a 13s pack. Not finished it yet, but there is no reason it shouldn’t work.
Its quite a bit of extra cabling and the way I am setting it up, i should also be able to use a 13s brick charger for when I’m on the road.
Once it’s all complete I’ll update here, but this is where I’m at so far…
6s6p and 7s6p 30q.
I really like this. There is a simplicity to it, even though it involves more effort to charge your packs. I have used lipo packs in the past. And once you get accustomed to the process of charging, and get over the fear of starting a 
, it’s not a big deal at all. One other thing I like about it… I am a bit OCD. And whenever I’m using a pack with BMS, I always have the concern looming in the back of my mind: Is everything balanced? The way you are doing it, you pretty much always check the balance plug on a multi meter prior to charging. At least I do. And if a cell is a little off…easy fix. I usually just run a balance charge at about .5 amps, and things usually get back in line.
I’ve only used the larger format ones, there’s a lot of new “active” balancers that use capacitors etc to transfer energy from one cell to another, instead of just burning it off through resistors. Some are better than others, and some aren’t even legit, but yeah, definitely my preference when possible.
I’ve got some larger ones I use for powerwall packs, that has Bluetooth and an app that lets you monitor the cells remotely and set various parameters, similar to this one: https://www.aliexpress.com/item/4000252216391.html?spm=a2g0o.productlist.0.0.1b9868fey52JKK&algo_pvid=2f6b3e64-f498-4730-a613-fe1721efa7f6&algo_expid=2f6b3e64-f498-4730-a613-fe1721efa7f6-11&btsid=0be3764515940162149588706e3309&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_
Yeah I agree, I mean, the RC crowd is already used to independently charging their packs, we’re using much of the same setup caveats, pack design strokes, etc, even down the XT connectors. Not a lot of standalone balancing chargers for packs of our voltage but, really no reason to rely on them.
I use modules like this: https://www.amazon.com/gp/product/B06ZZG2GPR/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1
(both can be had cheaper on AliExpress or eBay, run roughly $20 each)
Keep XT60 and XT90 connectors on everything, and I can charge any packs, either from my large 48VDC off-grid packs that I use to power my cabin, or through various large power bricks, or server DC power supplies when I’m at my workshop in town, can be set to any voltage and current within the ranges easily, and work great if you de-rate them by 20-30% total wattage. 3D Print some cases, I keep certain ones set at certain voltages and amps, and they can run CC/CV directly to your pack through the same XT connector you have hooked up to your VESC, or a separate one if you prefer.
There’s tons of tutorials on youtube etc on connecting to Server PSU’s in series, floating one, and bam, you’ve got a high current 24v supply you can boost easily to charge these packs (or you can make a 36v one, etc), and others for anywhere from $20-40 total, and they’re top quality, reliable, high efficiency units built to last and manufactured en masse, for that industry.
Let the balancer do it’s job, occasionally, when necessary. Let the VESC handle discharging high currents as it’s designed to do, and if there’s some other scenario you’re concerned about it’s easy to integrate on it’s own, although adding so many component points of failure along the high current path, which is potentially tougher than the terrain and vibration on some.
I know nobody wants to be careless about battery safety, I agree we shouldn’t, but I wonder how many setups end up going up in smoke because of the BMS’s and other stuff people have crammed into their enclosures between the pack and the VESC in that high current path, not able to actually handle it long term and thus being the cause of the pack meltdown when it’s supposed to be keeping it safe.
I think in this regard we’re better off looking to the EV and high end car audio scene, and how they handle high currents safely, because we’re way more in that territory than RC, drones, etc IMO.
This balancer looks interesting. Do you know if it will work with a pack with wildly out of balance cells?
Should definitely, although if somethings crazy crazy; like one cell is at sub-cut-off or showing almost no voltage, I’d revive it manually using regulated bench PSU and set the initial CC charge to like 100ma or something real low to start, just connect directly to that cell on both ends if you can reach it, get it back above normal cutoff voltage before running a full balancing cycle.
I’ve had great luck reviving cells that way, although if you’ve got one that’s constantly falling low, you may want to do a full bottom balance, and top balance cycle. Sometimes you may even need to overcharge a single cell relative to the pack to get it to even out, sometimes, you just gotta amputate and replace it though.
Vortecks has a 2 videos about a similar looking one, looks like it balances 1A per cell
here - after about the 1 minute mark. His first one was a dud though…
You can actually get them that have much higher balance current, but they get costly, and I’m not sure it’s advantageous for this application, but when you’re dealing with multi-kwh, or 10’s of kilowatt hour power wall packs, you take as much as you can get.
As with everything from the usual direct from China sources, it’s a crap shoot as to whether you’ll get a good one or not though. Still, lots of people in the solar/diy powerwall scene are using these lately.
Copying this from the battery builder thread…
@Andy87 makes a sweet charging harness, I bought a D140 offa him that is set up the same way
I got that one, it’s great. Balances accurately, bluetooth and app work well. Don’t bother with the cheap $20 ones, they don’t do anything useful.
