yup yup absolutely , I learned about China knock off connectors long ago when Rat Shack discontinued Switchcraft and Cannon in favor of the first wave of China junk. Trying to solder to chrome plated terminals.....bad ju ju. They were shiny though! lol
Sometimes deceptive advertising makes it hard to know for sure but failures in one way or another eventually tell the tale.
And yes , I admit that after soldering thousands of connectors I still sometimes forget to put the covers on first ! arrrgh
Good idea on mating the M+FM connectors before soldering on those plastic XTs .
I have recently finished switching all my solar patch to Anderson SBs and PP45+30s, probably just use the XTs on e-batts for now and have some extras or future projects . I like the fact that XTs are smaller than SBs though. The controller compartments on ebikes seem to be seriously short on extra space...and the anti spark XT90 version is going to be STD on battery connectors .
I have some thick aluminum stock I'm planning to use on the white b booster for an extra heatsink as well as the Delta fan. Good find on that 15a board mtd fuse ! So 10a limit for now. It is what it is. Replacing with a jumper and fusing outboard mod at least will make replacing easier when running up to the limits. Especially in a test lab scenario.
Some day that little jump pack will save your butt ! I'd keep it on the daily carry.
Also planning on trying those tool batt "caps" in a power supply for my old power hog 17" win 10 laptop that has eaten 2 comp power supplies so far . Probably try an ebike version with a booster sooner than later..
Scratches for the Comorant annoyer.....latah Gatah.
The solder 'cups' on the amass XT connectors can be turned with a pair of needle nose, so one can skip the tailcap and have the wires come.off at 90 degrees. The XT90S, do not try and turn the positive contact with the resistor though.
The space inside esk8 enclosures is also really tight, and the vibrations can be extreme.
Have to use the super fine strand and flexible silicone jacketed hobby wire with the 200C insulation.
One trick to using this wire is tiinnng the ends of the stranding inside the high temp insulation, so it does not expand when the insulation is removed. Makes it far easier to get 10awg into xt60 or 8awg into XT90.
The following 1 user says Thank You to sternwake for this post:1 user says Thank You to sternwake for this post • rvpopeye (10-09-2025)
Late last year before I dislocated my shoulder, I was in the process of building a new enclosure for a small lightweight Esk8.
An enclosure for a 10S1P 21700 battery, and I had built the battery.
I was actually using that battery inside my larger 10s2P enclosure, when the board got submerged in the bay.
Basically all work on that enclosure stopped entirely then and there.
This enclosure has a ridiculously huge heatsink, designed for 2 old programmable Vescs. I have some 80mm Hub motors which use a Julet 9 pin connector, often used on Ebike hub motors. I got the extension cables, spliced the three phase wires and the 6 sensor wires for one motoe, and decided to try that motor on a basic 7S ESC and battery.
The motor started making weird clunking noises that just sounded like a broken magnet inside. a physical internal interference. It could be a Mismatched ESC motor. it could be actual physical interior interference. I did not troubleshoot.
Thoughts of getting the Mini operable, again, faded to the background.
I now have known good hub motors which would be better on the mini build, and nothing is really stopping me from picking this project back up, other than when I put my powertrain on my midsize kicktail while working on my long cruiser deck. I disliked how it rode and lost confidence in my ability to ride it safely.
I do want a functioning reliable backup board, and a small lightweight board would be great, and I do have the cells and a battery half constructed for the Mini.
I should be working on it.
But Range brain took hold today.
The thought of strapping my old DMEGC 10s2p to the top of my long cruiser, and putting it in parallel with my BAK45D 10s2P through the charge port, is certainly the easiest way to increase my range.
Some potential issues are the charge port is only rated for and is fused at 10 amps, as is the BMS, and the ESC can pull 24 amps from teh BAK45D.
if put in parallel, I had no real idea what the DMEGC would be able to send to and through the charge port and BAK45D's BMS when I would full throttle accellerate to top speed.
I put the DMEGC pack into the Mini enclosure with some padding, and strapped the enclosure to the deck of my long cruiser.
I have an Anderson powerpole on the DMEGC pack, not fused, but which does go through the DMEGC's BMS.
I plugged a wattmeter in line with the APP, and plugged the DMEGC at 41.7v to the BAK45D at 41.4v, and there was about 0.4 amps flowing.
I put the board on the ground and went for a 1 mile long near full throttle run, by myself, scaring the shit out of myself exceeding 30MPH.
I then did a couple laps on my 'racetrack' where I would accellerate hard, brake hard, turn hard, accellerate hard, several times in a row.
When i stopped, benched the machine, and The wattmeter recorded 3.9 amps max, So basically 40% of the capacity of the charge port, the fuse, and the BMS.
When I stopped the DMEGC was feeding the BAK 0.7 amps, and that eventually tapered to zero and both batteries were 41.19v.
So this current from DMEGC was running through a pretty long distance of 18AWG and 16awg and multiple connectors.
The Main DMEGC output is 10AWG and uses an xt90S antispark connector, and Bypasses the BMS. The BMS is wired for charge only, to the ESC. Standard for Esk8, as the BMS cutting power means No brakes, and potentially streetface when it cuts power at full throttle when one is braced for accelleration.
The DMEGC pack was obviously not sharing the load of the ESC with the BAK battery which is much closer to ESC over 10AWG, and since it was feeding 0.4 amps to the BAK battery before the ride, and 0.7 amps after, it cannot recharge the BAK as fast as the ESC can deplete it, when riding aggressively anyway.
So I have now made a 14AWG xt90 to a 5.5 x 2.5mm barrel jack to plug into the charge port. A much shorter length.
So this should be able to allow more than 3.9 amps to flow from DMEGC to BAK through the charge port, its fuse, and the BAK charge only BMS, but I do not think the 10 amp limit is in any danger of being breached.
Ideal would be a parallel battery connection to the ESC, bypassing the charge port, fuse, and BMS, but that basically means complete functioning enclosure disassembly to add an external XT90 panel mount, and I don't want to disassemble the board, and waste about 3 dozen Zipties which are immobilizing every wire inside.
Anyway. The DMEGC pack was good for about 6.5 miles towing Fiona at moderate speed with my old hub motors and my old 8x3" turf tires which i kept at super low PSI. My BAK45D pack is good for about 10 miles on its own right now, and both together, Should be a considerable range extension, without having to stop and hook up the portable charger, but that is obviously still a possibility too.
So the DMEGC was 187 watt hours new, the BAK is 324 watt hours, and I have the 104Wh 7s2p portable charger that I can plug a 55.4 wH 7s1P into, and the 222 watt hour 3s4P 50E, and 6 power tool batteries at 72 watt hours each I could put in the chariot roll and explore quite the distance from home base.
And I do have boosters galore.
I am also about to make a 6s1P Samsung 50E to power my TS-101 soldering iron which is another 108 watt hours which will be able to power a Vbooster to recharge my ESK8 batteries.
I did test the White booster on the bench with my powermax holding my Dekas at 13.6v, and at 15 amps input was getting me about 4 amps of output, 168 watts, so about 18 more watts than I can get from the Blue booster.
I was losing one volt on the length of 10AWG from Dekas to the booster. I could wire booster directly to powermax, but I like having the Dekas in between to smooth the ripple.
So I am still quite a ways from stressing the charge port or BMS or the cells in terms of rapid charge ability.
If I choose to use the top mounted enclosure, I can basically charge that battery at 4 amps, and and the BAK battery at 4 amps, and then reparallel them and return range twice as fast. Have to be careful they are relatively close in voltage when parallelling them though. or bye bye fuse.
10-11-2025, 07:43 PM (This post was last modified: 10-11-2025, 07:46 PM by rvpopeye.)
I was wondering how much current I could push through that charge port .
I haven't opened up the controller or battery compartments yet,not in any hurry to either . After seeing how some mfgs pack it all in , I'm thinking that it all is packed in only one way or not fit if you don't know the right position and sequence of every piece like some kind of puzzle ! Gonna need a lot of pics with lots of extra lighting. I'm getting an extra factory pack to satisfy range brain for now...I was thinking of making a Y adapter with water resistant fuse ports on both legs added for whatever connectors are used by mfg. Hoping I can tap in between the batt and controller somewhere in the outside wiring.
. Most rides I get 15 to maybe 25 mi. Between trying to make sure I have enough juice to cover the return trip and not wanting to run the battery pack down too far . I have only ~650 miles of data to go on. Range Brain must be appeased though. So far , I know this .Going slow really increases range . But there are situations where max power is needed to get across traffic or at red lights when surrounded by too large and or loud pickup trucks LOL . Walking/bike trails are great but never go very far around here . There , I'm the guy in(on) the big thing with a motor !OMGoshk ! hmmmmmmmmm
But I go slowest there and enjoy the river , ocean or woods scenery depending on which trail.
There are lots of dirt bike trails but most eventually have areas "I'm just going to try to survive today" so I just turn around.
Gotta know your limits when you're my age I tell ya ! and I of course go beyond that way too much already.
Finally had a day where it barely got to 80f, and Fiona was game to walk through the park a lot farther than usual.
She will often just step and look at the chariot, so i remove the esk8 from it, and tilt it back so she can step in, and off we go. Dial a breeze, and i did not have to dial as much if it today and we rolled the usual zones at a more sedate pace.
I decided to try my new XT99 to 5.5x2.5 90 degree barrel plug today, on the white booster, and I watched 175 watts drop to zero.
Turns out the DIY barrel plug center part which touches the center pin on the charge port was offset to one side, so rotate it one way and a solid connection, rotate it 180 degrees and no connection, any point in between and maybe yes, maybe no.
I soldered 14 awg to it, maybe melted the separator, or maybe it was that way before I soldered it.
The pin in the receptacle is not centered, so it grabs one side of the interior barrel to make contact, so if i were to solder it mated with a spare receptacle, it might induce that which I am trying to prevent.
This 90 degree diy male barrel plug has not given me issues, soldering 16 or thinner gauge.
The second roll didnt happen but a flaky intermittent charge port while riding with a range extender pack would be bad, perhaps consequential to BMS, maybe ESC
The Dell laptop barrel plug always gave me issues. I recLl stripping it andd soldering wire at 90 degrees to it, then potting it in Amazing goop.
I might look for a different male 5.5x2.5 plug with a better design to grasp that receptacle pin more tightly.
perhaps a different connector altogether for the range extender.
This one was never intended for handling vibration.
The rolling guppy with range extender enclosure on deck.
0-20mph in 4.5 seconds, towing Fiona.
The Guppy surfboard is a bit of a frankenstein too. It had seen tons of work and added bits and pieces and reinforcement over the years. The skateboard deck has also seen multiple reinforcements with chisels and routers epoxy and fiberglass, and rolling guppy is a better name than long cruiser.
I can see the wattmeter display underway, but not read it. It does record Peak amps/ watts and minimum voltage and amp hours, So I can see what I need to see when stopped.
I'll not use the wattmeter when i actually strap the range extender to the deck. I could, but would have to use my xt90 to APP adapters and that is just more mass to vibrate. I do have a wattmeter with xt90s on it, but this one does not work properly in that it does not record peak amps for more than 15 seconds or so.
The 90 degree DIY plug is the third of 5 that I have made. The other 2 work fine in any orientation but use 16 and 20 awg wire. One is just for a voltmeter with a long enough lead I can hold in my hand and see the voltage drop under load.
The old DMEGC pack was dropping from 42 to 36.5v, the BAK pack was dropping from 42 to 41.2 under max acceleration, and I was going 4MPH faster when reaching the same waypoint.
I'll need to closely inspect the other 2 DIY 5.5's before going further, and perhaps commandeer the voltmeters as i dont really need it, and have not used it since the acceleration voltage drop test.
The following 1 user says Thank You to sternwake for this post:1 user says Thank You to sternwake for this post • rvpopeye (10-12-2025)
10-13-2025, 06:35 PM (This post was last modified: 10-13-2025, 06:43 PM by sternwake.)
I was closely inspecting my 5 other 90 degree 5.5 x 2.5 DIY connectors, and none of them was the center barrel perfectly centered in the insulation within the outer barrel. I then looked again at the one that failed, with some good reading glasses and saw less than ideal soldering. I wiggled the wires and the negative was basically loose.
Not bonded. Open circuit if wiggled this way, closed when wiggled that way.
I gave the positive wire a bunch of stress and it remained, so I reflowed and added esolder on the negative and gave it a vigorous stress test and it passed, so i reattached the body.
My esk8 battery is full so I can't pass 170 watts through it and test it under load, but I did plug my wattmeter in and wiggle and twist and spin the connector and it never varied from 41.97volts, despite the off center interior barrel contact.
So, hello crow.
I built my 6S1P Samsung 50E the other night. 21.6v nominal, 25.2v full charge. 5 amp hours, 108 watt hours. 9.8 amp CDR. 40 AMP BMS with balance.
I was going to add the 7 PIN JST connector to be able to easily check cell balance, but would have to solder the leads to Stainless steel, which does not work, and even if I had used nickel plated steel which does solder easily, the wires would have crossed over each other, which is undesirable, and I basically do not need to check balance on a cell built with quality, perfectly balanced cells when assembled, and which also has a balancing BMS.
Built it basically solely to power my Miniware TS101 'smart' soldering iron. This iron can accept a USB C, or a 5.5x2.1 barrel plug. At 25v it can draw 82 watts, and heats to 400C in about 7 seconds. It can draw more wattage if fed from a 90+ watt USB C capable source, but I dont own one of those, and love the portable factor of a 6s1P
I was using a chinese 55wh prebuilt 7S1p esk8 battery to power it, but discharged to 25v or less, and it would sag pretty far and not last very long.
I used the new 6s at 24.54v Samsung 50E tonight to power the iron, and max wattage was 81 watts.
This 6s1P has more capacity than the 7s2P inside my portable charger, but at 10 amps max output, is not ideal. it is however pretty small and I can fit it in my pocket with the white booster and easily add a few miles of 'get me home range' if needed.
My 28$ 1800 watt/ 40 amp voltage booster bought on Ebay, was shipped 'economy shipping' , no tracking, expected delivery " by October 30th', arrived today, the 14th. Was Not USPS. I got a text saying my package was delivered while at the park with Fiona, and assumed it was a spam text, but Alas, it was at my front door well before USPS ever arrives.
I have made some 10 AWG ring terminal to 45 amp APP cables and am testing it now, but only at low amps as my Esk8 batteries are quite near full.
So far so good, and it seems to be quite efficient, wasting only 1.2 watts boosting 11.98v to 28.34v at ~ 20 watts input.
it is a pretty big bulky booster in comparison to blue, red or white boosters, but bench charging, this is no concern/ I should be able to charge at 420 watts, 42V 10 amps output, from 12v nominal without issue, where my other boosters seem limited to the 150 to 170 watt maximum.
It is a bit bigger than I'd want for stuffing in the chariot's fanny pack, just to be able to charge from my 3s4p at more than 170 watts.
I'll be testing all my boosters using same wattmeters on input and output, from my GC-2 AGM's, feeding my Esk8 battery, but this one is obviously the most capable, and if physical size is not a factor, I'd recommend just getting this one rather than bothering with the blue red or White boosters.
I got to say the blue booster for under 150 watts will continue to be my favorite. mainly as it has the LED which can be dialed via potentiometer to turn from red to green when amps taper to below a chosen level. i can walk into the garage and see a green light and know the battery is accepting somewhere less than 0.3 amps. the red booster has no lights. The white booster has a red light but stays red whether it is uoutputtng 170 watts or 1 watt, same with this 1800 watter.
Right now, I am charging my premade junky 7s1P battery from my 3S4P Samsung 50E at ~ 30 watts. The Samsung's 3 parallel packs are staying within 0.004 volts under any load from 2.5 to 15 amps, which I find impressive, but perhaps is not.
The Big red booster is staying cool at this level. It has a fan attached to its heatsink, but it must be temperature controlled as it has not yet turned on.
The proprietor of diy500amp dot com says he has three of these big red boosters, and says they are good. He has modified one of them with better rated Mosfets diodes and capacitors.
Mine came with the output adjusted to 58 volts, and when dialing down the current potentiometer, 0.68 amps seems to be the minimum throttling it is capable of, where my smaller boosters will throttle ma amperage to much lower levels. This can be good if trying to allow the BMS to balance an old pack which falls out of balance easily.
Poorly made battery packs of dubious consistency( or well aged) cells seem to need to rely on the BMS to top balance, but these also only can bleed off voltage with something like 0.02 to 0.035 amps of current, maximum, so if badly out of balance a faster charger will basically be too fast to allow the BMS to fully top balance a pack.
My Dumb Daly BMS's start balancing cells when a p group reaches 4.18, so i will set the charge voltage at 41.8v( 10S), and will dial amperage down to the Sub 10 watt level. I can then bump max voltage ( unloaded) to 41.85, .90, .95 at these low wattages and in theory they wshold have more than enough time to perfectly top balance.
But really this is not vey important. It is said unless parallel groups start varying more than 30 MV, then performance is not affected.
I have not bothered testing my BAK 45D 10s2P balance in a long while, and feel like I need to scold myself for even charging it to 42 volts as I rarely have issues with range, and charging to 4.2 volts is unnecessary and will negatively affect cycle life.
but compared to Lead Acid batteries and their shit poor service life unless coddled and quickly and fully recharged every cycle......
1200 Cycles should be easy to accumulate when cycling from 4.1 to 3.2 volts with Liion cells.
Manufacturers wll spec numbers like 400 Cycles at 0.5C charge, 2C discharge and 80% capacity remaining, cycling from 4.2 to 2.5v, and these are just guaranteed minimums.
I am rather amazed 20 21700 cells made into a 36v nominal battery under my feet can propel me and Fiona to 25mph and give me 10 miles of range and do this thousands of times before it might only be 8 miles of range.
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