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

[sternwake]

The ordered board has 6inch diameter wheels, and they are airless rubber, not pneumatic.

The 4 ply turf tires in that photo are about 8.5" in diameter, and 3" wide.

Surplus Center had some 10x3 2 ply tires for 2$ each that I didnt need, but I had mistakenly bought inner tubes for that size tire.

If they are not out of round, should provide a cushier ride for Fiona, and still fit in the kayak hatch.

[rvpopeye]

If you get those tires on everything , you will probably be able to do beaches too!
Fiona won't like that too much, will she ?
Well the too much part should still apply.LOL

[sternwake]

The too low to be true pricing on the electric skateboard, was indeed that.

For several days the purchase history page just said 'paid' next to the skateboard.

Then a few days ago I get notification that it just shipped, and here is a USPS tracking number.

I click that number which takes me to an authentic looking USPS page and it says your package was delivered yesterday.

Hmmm, shipped just now but arrived yesterday.. Okay...

I did the ebay chat thing just typing agent over and over until it said we will have someone call you within 10 minutes. They did, I outlined the issue, they said give us a few days.

I gave some feedback on seller, and then got an Email saying my tracking had been updated. it now said it shipped from within Florida a minute after I ordered it.

Got an email a few hours ago from Ebay saying we are reviewing your case.
Then another email shortly after saying I have been refunded the full amount, but it will take a day or 3 to show back up in my account.

I would have enjoyed that 600 dollar skateboard for 96$, but oh well. I'll be getting my money back, pretty painlessly.

The large 10 inch diameter hand truck tires from surplus center, out of the box were pretty wobbly and out of round. They are a little bit too big for the rim and I have to be careful the rim is centered before adding PSI above 15 or so and locking that center. I tried them underfoot going super slowly, before putting them on the chariot, but that wobbly out of round first attempt was too dangerous when turning. I swapped them to the chariot, and the chariot then wanted to coast longer than my skateboard did, upon releasing throttle and coasting.

The comfort level of these tires for Fiona has to be much improved, especially now that I have recentered them and gotten them hot and they have largely dewobbled themselves, and I added a few balancing weights opposite the valvestem.

Towing her across the crushed shell trail has never been easier, and now the chariot itself is being rebuilt with a better basket, made mostly from recycled pallet doug fir that I dimensioned on the tablesaw.
It is turning out lighter than I expected and is still overbuilt, but at the moment under fastened as I ran low on screws, so there is only one and no glue, where I expect to use no less than 2 screws and glue, or perhaps epoxy, on final reassembly.

I've not finalized the design, but it will have good airflow through it to help keep Fiona cool, and will have some fenders covering the pretty large wheels, and storage for leash balls and water and shade, and a way to carry both Fiona and the skateboard, balanced so that the handle weighs little.

The large 8x3" pneumatic turf tires up front and the long cruiser deck, increase confidence and comfort so much, I go faster everywhere, and the battery is likely now approaching 1500 miles on it, and its voltage is sagging more, yielding less torque, especially on the second half of the available watt hours.

This 10s2p battery, being my first, used low dollar(2$ each) 15 amp CDR 2600mah cells.
I didn't want to screw up high $/quality cells on my first spot welded battery build.

But the highly respected Molicel p45B is a 45 amp CDR 21700 cell, with 4500mah, is now down to 4.85$ each, and the nearly as good P42a is down to 4.15$ each.

I can easily fit a 10s2p of 21700 cells in my enclosure, and these cells should be able to retain far higher voltage under load, and hold it higher for significantly longer, meaning more torque and top speed for longer, and a cooler running battery which can be charged much faster when that is desirable.

But I might be getting a new/used Esk8 deck which can fit 48 21700's, in a 12s4p configuration, or if I wanted to keep 10s, I could fit 50 21700's in a 10s5p configuration.

This future E board will likely be getting belt drive with a 4:1 reduction, and driving no less than 6x2 inch pneumatic tires. Top speed should be around 36mp,h and it should have about 4 times the torque and acceleration and range available, and be able to climb hills easily. For if / when I get to escape Florida's flat overheated insanity



I have not put my window motor back together, nor seen my Van since I removed the actuator and motor a few weeks ago.

The Van is too ugly to park in this neighborhood, and honestly I don't need it, other than to go buy some new landscaping and bags of topsoil and mulch.

Not having airconditioning, makes me not want to drive it here, this time of year anyway.

When I need to go for a ride, It is far more enjoyable to load Fiona in her chariot and tow it with the electric skateboard, especially with the nice pneumatic tires which cross sidewalk cracks silently and smoothly, compared to 90mm urethane.

[sternwake]

I wish I had an odometer on my E skateboard, but doing some math estimations, I have to have 2500+ miles on it, at this point.

No less than 90% of those  miles are Towing Fiona in her chariot.

Her chariot's tires are actually over 12" diameter. 4.10x3.5-4's, not 10 as stated in previous post.

4.10.inches of sidewall thickness, 3.5 inches wide, on a 4 inch rim.

I started lowering her tire and my tire PSI, in stages just to see, and was down to 4.4 psi in my turf tires and 7.8 psi in her chariot.  Such a  cushy ride.

But then I opened my battery enclosure after a longer ride, a ride in which I carried two of my Ridgid drill batteries, and using those to power a voltage  booster to charge my skateboard battery at 140 watts while we walk through  farther parks that we rolled to at 20mph.

The exterior of my battery was reading 55C. The cells themselves have to be much hotter that what makes it past layers of barley paper, kapton tape, and thick Heatshrink wrapping.

I did another ride without the park charging and again found 55C+.
The cell spec sheet say 60c max, and don't  charge above 50c.

I had been slapping this thing on a charger almost immediately after a run, 3 times a day for months now!

I've been cooking this battery!

I finally  completed my 10s1p battery that uses Molicel P42a, which are temperature rated to 45 amps continuous discharge rate.

I pulled out my cooked 10s2p battery, and installed the significantly physically smaller  Molicel 10s1p p42a , and charged it up to 42 volts.

I went for a solo run, jammed throttle to max and there was at least 20% more torque on tap, and it was willing to go faster than 24 mph or so, the point where I am.like Efff, this is dangerous and be extra hyper vigjlant

.After a few miles of scaring myself with my love of adrenaline, 
I returned home, Loaded Fiona in her chariot, and again was surprised at all the extra torque available, even with a semi depleted battery.

The much lower resistance Molicels are able to maintain much more   voltage under load, which basically directly translates to higher motor torque.

The capacity if the DMEGC  10s2p is 5.2 amp hours  and it is rated at 30 amps.
The capacity if P42a 10s 1p is 4.2 amp hours, and 45 amps, 80c cutoff

I suspected it would out torque the physically bigger older  abused battery of low  cost cells, but  the degree to which it does, is still a bit mind boggling, but I guess should not be.

The Molicel.pack is intented for my 'grocery getter'  a small nimble lightweight board whose enclosure is slowly approaching  completion, 


I am.reluctant to remove it now., but can put that new  enclosure on the long  cruiser, so, all hail adaptability, and onward!

The Molicel p42a is now pretty low on the totem pole.of  liion  cylindrical cells.
The Molicel p45b eclipsed it, and now the p50b is another huge step up, but it is expensive,and largely unavailable, and  already out classed.

'Tabless' cells are able to eliminate  electrical   choke points, eliminating the localized heating and extra  resistance caused by a single tab,  or dual tabs on the 'jellyroll'

Tabless cells such as the EVE 40PL,  BAK45D, and Ampace JP40, have tabless or. continuous tab design, and far lower internal resistance.

The JP40 is rated  for 140 amps for 5 seconds, FFS!  That insane power in a 21700 cell, and initial cycle life testing looks great.

I just ordered 22 of them.

One of the extras will be for my one 21700 headlamp, which can draw 11 amos on its 3800 turbo lumen mode.

The other is basically as one needs to experiment with the energy required to spot weld to battery itself, and each brand is a bit different, in the steel alloy used on the cell can, and its thickness, and the thickness of the nickel plating covering it.

I am going to employ the  copper nickel sandwich method again, and can do 0.1mm copper  capped with 0.1mm nickel plated steel with my   modified 'purple' 20$ spot welder and current weld battery.  O.1mm copper is ~equal resistance to 0.4mm pure nickel, and the  cell cans thickness is usually 0.3mm of nickel plated steel.

Minimizing resistance was a good lesson from living on 12v lead acid struggles.

I get mocked  for my oversized  Eskate conductors, but had my cooked battery simplyy used 0.15 nickel, instead of 0.1mm copper,.I might already have  completely failed battery,   from  seriously localized, and general overheating,  Its still working fine with a good oortionnofnits original capacity, its just thatbits resistance has increased. it ddoos.more voltage under load and gets hotter doing so, than when newer, and is aging faster and faster.

Van wise, Im pretty sure I can  fit 608ah of prisimatic LifePO4 cells where my 190ah of 7.7 year old  GC-2's AGM's reside now.

I hope that the recent improvements  in battery performance can continue on a similar trajectory, but hope seems pretty damn well Fucked.

So, I want to make every day with Fiona count.

   

[rvpopeye]

She looks very aerodynamic !
Extra speed won't cause any complaints with that passenger.!
Thx for the new battery update info.They sound promising.

[shadowmoss]

I was wondering how you two are doing. Thanks for the update.

[sternwake]

We missed our evening cruise yesterday, and this AM drove(a car) to the park with Mom.

The skate had its battery removed, as I needed to test fit it in the new enclosure.

I returned it in time for our evening cruise
, and once again the torque increase  of the smaller battery was impressive.

Fiona was going nuts with excitement when I pulled out the chariot and then the reassembled and fully charged skateboard.

Driving in the van, she loved to stick her head out the passenger side  window and bark and bark and bark.
It's the same in her chariot, and I just join in, she barks twice, I bark twice.


I know its unfair to compare a high mileage well baked battery  of mediocre cells with a smaller new one made with quality cells, performance wise, but here are both side by side for a size comparison.

   

I joined battery Mooch's Patreon account to get access to his detailed testing data and industry insights and general advanced knowledge on all things lithium battery, though drop Lifepo4s and prisimatics are not on his radar.

The Ampace JP40 cells I have on order are indeed very impressive performers.  Its kind of crazy that a single 21700 cell can output 350+ watts.  Looks like it can maintain more voltage at 60amps, than my Dmegc cells can at 8 amps.

They are about 5$ each.
The EVE 40pl is available for 6.25$, and are excellent performers too.
The BAK 45d is not readily available in the US, but is somethjng like 4 euro and has similarly low resistance to the other two tabless cells above, and slightly higher  rated capacity.

Sony/murata have a tabless VX40, but is not for sale to the public. 
Have to buy a specific 40v Makita battery to get them.
, but hopefully they have enough leftover to be sold to us peons soon, and drive down prices.

The Molicel P50b is not a tabless design,  but can perform nearly as well, and outperform them at slightly lower currents.  Its out if stock everywhere but can be preordered for 10$ each, and since the tabless ones listed above are so much cheaper, might be repriced to be competitive.

When Molicel pays tesla to use their tabless patent, the cell they deliver should be another order of magnitude greater in performance and  cycle life.

I got a Samsung 50s (5000 mah)for my Armytek c2promax headlamp.  It is a good performer but runs very hot at high amperages. There is a noticeable  improvent in brightness and run time at high brightness, over the  cell it came with.

Also got 4 EVE 35v 18650s, 3500mah, as all my old panasonic ncr18650bs started getting way too hot when charging, and suffering from very obvious capacity loss . The Eves are flat tops, but i got some button tops to weld to them so they work in every 18650 device I own.  I used to do solder blobs without much issue on flat tops +, but its nice having a spot welder.  These 3500mah EVE cells  make my flashlights brighter, for longer, and they stay cooler, and My bluetooth speaker seems to have more bass punch.

I have one 14500/AA flashlight which got a new cell, Vapcell, forget which model, but it vastly outperforms the cells I had been using in it. Vapcell.is a battery rewrapper, not a.manufacturer, but they seem to use good cells, and actually market the highest capacity 21700(6000mah), and a 4000mah 18650 available.