So it begins...... Battery spot welder

[sternwake]

The new 7S 25 amp BMS that i ordered, has no documentation, but this listing says recommended charge voltage is 30v. and that cell' equalization' starts at 4.15VPC and 0.04 amps is the max balancing current.

I've not seen any documentation anywhere regarding BMS's saying overvoltage is required for cell balancing, but the BMS in my larger skate input voltage is about 0.4v higher than the XT60 connector that feeds the ESC.


I've no idea what BMS is under the heatshrink in the 7S2P battery. size and shape might be the same as the new one i ordered.

Seems like 0.4v is excessive drop across the BMS, to me.
But that is the same as a Diode, and there has to e something alone tbose lines as the charge port sbows no voltage.

The cell.over voltage prrotection is 4.25v per cell.
I guess ill have to determine what is going on within, once i have built a battery and can hook test leads and the current clamp up easily.

But is seems likely I've only been charging to 4.14vpc instead of 4.2v. Good for cells, bad for achieving max range, which has not been an issue.

The little skate is so fun, just underpowered. Torque limited.
I coukd use that second truck with same hub motor, and put it on front.
would need a dual drive ESC.

The duaL drive 7S ESC in my larger skate has that borrible throttle and brakes.
The motors haVe hall effect sensors, and some esk8 forum members say the HES are used only to get stationary board moving, and to automatically turn the off board to on whennit is oush started manually, and that the brakes imoroved greTky with sensors disconnected.

I pretty much never ask board to start me moving from dead stop, and the push to on feature is more annoying to me than a feature i take advantage of.

So perhaps i can just disconnect the sensors, and have better throttle response and brakes.

Wonder what the risk of magic smoke ejection is by doing so.
Whichh leads me to desiring a backup ESC, and a backuo board capable of towing Fionas water chariot to the bay too.

The cheapest esk8 dual drive ESC is in the 62$ range.
But the oictures all looknthe same, but some say 24 to 36v, othere say 10s onky, some say for belt driven motors some say hub motors.

Wonder if my horrible throttle and brakes are because of the ESC being for belt drive motors and not hub motors.

But my esc, is apparently unicorn tears, i cant find any links anywhere to it or any pictures anywhere online of an ESC with same layout of circuits.

There are 3 different dual drive ESCs on e bay in the 62 to 114$ range.
One of those has a soot on unootted circuit board, where one can add a sokder bridge a ross two terminals and use it wjth a 6s battery, or two other terminals for a 7s battery, and no bridging for a 10s battery.. It said it is for hub motors.

I had to order it, because i could 6s it to drive two 24v kayak thruster motors, or 7s it to use on larger skate, or 10s it for when i decide to make a new enclosure and a 10s battery.

Options, good to have them.

And the super fun miniskate could potentially have 2 motors, driven by a 10S battery, using Molicel p42a 4200 mah cells with a 45 amp CDR.
14 unknown CDR cells of aupoosed 2000mah capacity in a 7s2p bTtery pack gets me to launch and back easily.
7S1P of Molicell p42a should do so with more room to spare, and 10 should laugh at the that task.

so i guess researching and shopping for a 10s BMS is next.