I doubt the voltage will be off at that distance.
I’ll think on it. But I really don’t see a good place to mount that on my enclosure and ive got much less ground clearance.
That’s only with a lot of current, as the balancing is nearly done the current drops so the accuracy goes back up, it might add some time to balancing but it shouldn’t be less accurate
Thanks for explaining this, actually I think I will adopt this for my first smart bms battery pack because yeah, they’re huge!
Another awesome feature that I figured out is that I can unplug the charger from the wall while keeping it plugged into the board, and the BMS will say on and static balance the pack.
Im actually considering turning the SmartBMS into a stand-alone plug in static balance/pack health monitor, and wiring up a different BMS to the charger. One that has a higher balance current. The balancing capabilities of the SmartBMS are not great. Really low balance current.
1 Like
I think llt is around 50ma for balancing so yeah it’s pretty weak…but instant monitoring compensates 
50mA is plenty, unless the pack has drifted a lot. And it won’t drift if its in a good condition and you always balance charge.
Let’s take bets. I’m guessing 60 hours. Lol
6 Likes
Which from my understanding would be anything above 0.05A of difference which in retrospect isn’t alot
Pros and cons of Malelectrics and K weld?
keep on goingCheaper, works great, can be purchased as a set up to run off a car battery. Doesnt look great, has a tiny fan that runs all the time (not loud). Has to be shipped from Germany(?), and those shipping costs can vary (though when I bought mine it was still cheaper with shipping than a kWeld.
Never used a kWeld so other than the price difference and the fact that it looks a lot better, I got nothing.
1 Like
Haha, yeah, that’s basically it, lol.
Seriously, the Kweld has a different way of laying the weld down. IIRC, it measures the energy being dumped into the weld and adjusts accordingly. So when things heat up, it compensates. It’s really a nice welder with a price difference to match.
The Malectrics has a simpler way of delivering the current required for a weld, so you don’t want to run it so fast that it heats up too much. Check welds when the welder is at working temperature. One big plus is that you can buy a car battery terminal connector with your Malectrics and when it arrives (DHL express) you can pillage the battery from the wife’s car and get welding right away. It’s a solid welder, far better than the Suunko. The auto-fire feature (KWeld has this too) welds after a delay when you make contact. Make welding a breeze.
4 Likes
I hated this at first but now I love it. Sounds really cool too, like a photon gun getting revving up to shoot a lazer
Nice!
The BMS has a balance only while charging feature you can turn off. Then it’ll balance always when the balance leads are connected
1 Like
Yep! Its called “static balance” in my app version, and I use it to great effect 
2 Likes
Just to be clear 99% BMS apply a super small load to the P group that has the highest voltage until it’s within a certain amount of the p group next to it. For all the BMS used in eSk8 none of them I have come acros do any thing with transferring voltage or changing charge.
A BMS is suppose to give a little nudge in the right direction of a healthy pack not compensate for bad cells.
The largest bleed resistors that I have seen in a BMS at worst case scenario ignoring all resistance the bleed circuit adds and dropping off current in a charger.
DieBieMS 15Ohm at 4.2v 280ma 1.176W
FlexBMS uses a 47Ohm at 4.2v 89mA 0.375W
30Q 18650 standard charge 1.5A Fast Charge 4A
VTC5A 18650 Fast Charge 6A
Let’s take the most common 4P pack
30Q 4P is 16A Fast Charge 12000ma
VTC5A is 24A Fast Charge 10400ma
DieBieMS
30Q the bleed resistors would take 2 days to bleed the P Group (in reality only 4 resistors can operate simultaneously so it’s more like 6days) or the resistor is 1.7% of the Max Charge Current
VTC5A bleed resistors is 1.2% of the Charge Current
FlexiBMS
30Q the bleed resistors would take 6 days to bleed the P Group or the resistor is 0.7% of the Max Charge Current
VTC5A bleed resistors is 0.35% of the Max Charge Current
These small% are fine because health good quality battery’s drift by fractions of a % why My opinion is you don’t have to balance charge every time but when you do it takes a little longer
2 Likes
whats an acceptable difference in voltage when it comes to putting your p packs together? is 0.03v okay?
1 Like
idk pragmatic answer for this yet. I think i’ve heard shoot for 0.02v
but there’s a calc to it.
I = V/R
V = voltage difff. = 0.03v
R = internal resistance of the cells in the loop. ( gets complicated if you just smashed 5 cells to gether… ) let’s say it’s 20 mΩ (though this guess has a wide swag in it. )
I = 0.03/0.020 = 1.5 A instance balance current.
seems ok?
this is all from reading. feel free to double check me on it.
4 Likes
I would put fiberglass around the edges of that enclosure or it will probably crack.
1 Like