I bought one of these Raft pumps —- It Blows and It Sucks
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Well, a very interesting and useful score for sure. Should come in handy for many things…. since “It Blows and It Sucks”.
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Wuben A21 Rechargeable Tactical Flashlight for $77 + free shipping
Apply coupon code “KFGJY4LL” to save an extra $52.
Features
• 7 light modes
• USB-C charging
• IP68 wateproof rating
wondering if there’s a code for the 60V 5A supply?
Perfect, tnx!
Was needing to test some heating elements and see what low-value DC I’d need for constant low heat, vs 120V and crappy bang-bang thermostat.
This beats trying 12V/18V/24V adapters.
I got mine yesterday. Yamctopy Portable Tire Inflator
It appears there is a BMS. Immediately opened it up, greased the gears and pump with silicone grease, and charged the battery over night. Then discharged it with a lightbulb pulling 2A hooked up to a [Wattmeter]. Unfortunately it terminated when I wasn’t looking so I lost the discharge capacity. Hooked it back up to the RC charger on [Discharge mode] @ 0.5A. Voltage plummeted rapidly and cut out again at 9.0v, indicating a BMS. Plus I could feel something under the shrinkwrap.
Charged it back up using an RC charger @1.5A which is about what the stock USB system seemed to be initially putting in. Terminated at 12.6v/1573mAh. Specs on the battery indicate 1.5Ah. For once the specs seem to be in line with marketing if you accept 1.5Ah x3S=4500mAh, which I don’t. 
Could not find any data on the batteries.
While the battery was charging on the RC charger I rigged up 2 x 3S 2200mAh lipos in parallel (lots of capacity), attached a Wattmeter, plugged that into the compressor, and tested it on a mountain bike tire. The gauge seems to run 5-10psi high. Does not seem to be linear, being closer to accurate at lower pressures and diverging as it went higher. This is compared to a digital gauge and 3 different analogue gauges, which are all very close to one another.
Addendum: filled up car tire from 35psi>40psi. Took 2:45. Pressure difference against digital gauge was 1 1/2psi high.
At lower pressures (20-40psi) it pulls 3.4A. As pressure rises the current does also, breaking 4A, and topping out a 4.5A when I set the pump to go to 80psi. I didn’t push it any harder than that. It ran smoothly, loud enough that I wore hearing protection at close range.
FWIW, I did hook the battery up to a 4 stoplight bulb discharge device and it pulled over 6A. The battery only got a little warm after 5” and the wires were fine to touch.
I also removed the connecting rod and piston and silicone greased both the piston “O” ring and the cylinder “O” ring gasket, and also the cylinder itself. Ran nice and smooth, but like you, I noticed the pressure reading was off by a good amount. Easy enough to adjust final pressure with my own gauge.
The battery pack in yours looks very different from mine. Mine looks like the pictures from the Amazon review I posted earlier.
Bluetooth headphones for $40
Wired headphones $15
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I noticed that. I’m not surprised. Sourcing materials for production is probably a hassle for them. Since it’s an item most people will never see, and not have the ability to test, it’s not a serious consumer problem for them. Near as I can make out it’s a ‘decent’ 18650. I’m hoping the relatively low capacity puts it in the ‘high output’ camp, not just ‘crappy battery’.
Could you tell if yours had a BMS? I could see and feel the board under the shrink, so I pulled the whole thing off, then had top pull a sticky cover off it.
Sorry for being ignorant… what is BMS?
Battery Management System — keeps them Li-ions from going BOOM
Lion in series need to have individual cells monitored and balanced so the pack integrity is maintained. Unlike NiXX, simply adding charge to Positive/Negative does not go well over time as the pack cells may go out of balance=end up with different charges.
If you’ve pulled apart a tool power pack, or a laptop battery pack the electronics you saw was the BMS.
On my inflator pack the BMS was an obvious hard rectangular piece covering most of one side of the pack. I was pretty sure it was, but opened it up anyway to see. You can see it in the 2nd picture in my photos above.
I tried to look up some of the chips, but; 1. didn’t go well, 2. I don’t have background to interpret them very well anyway. They are generally written in “electronic engineering” speak. Not my field.
How WELL the BMS does it’s job can be variable.
So very true. A lot of removable laptop battery packs would end up unusable because the BMS either didn’t properly manage even power delivery from across all cells (causing one cell to go bad), or created with such a deficient BMS that even just a minor drop in capacity for one cell would compromise the whole pack (triggering auto-shutdown well before the whole pack was at the minimum voltage threshold). I can’t tell you how many times I’d have a poorly performing battery pack that when harvested for cells would reveal 3 perfect cells and 1 cell with just a slight drop in max voltage (4.1v versus 4.2v).
I’ve converted a number of old NiCad power packs to Lion. I absolutely do not use a BMS, never have. Don’t entirely trust ’em. I’ve had the same experience harvesting laptop cells as you have. Some just do a poor job, even on what I would consider high(er) grade, sensitive electronics.
I have a hobby charger with [Balancing]. I wire conversion packs up with a balance tap, cut a notch in the pack housing, and dangle the tap out the back or side. I also have a small voltage tester I can plug into the tap and see what the voltage on any given cell + the whole pack. One even has a loud low alarm I can set.
Thanks for the explanation.
Yes, I do see a long flat rectangular piece under the shrink wrap.
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Almost all generic Chinese made 18650s have low capacity and poor output (amps), compared to Taiwan, South Korean or Japan made batteries.
I’m fully aware.
These aren’t claiming to be mega-high capacity on the cell printing (1.5A). They do seem to hold up pretty well to medium current discharge on my limited testing. So, time will tell. Replacing the pack should not be a major hassle if it comes to that. Not sure what will fail first, the pack or some part of the motor. The gearing system certainly could be more robust.
The Chinese batteries in the PF video are complete jokes.