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King Song Charger Getting Very Hot


dbfrese

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I set my KS16S charging through two chargers with Charge Doctor V2, with the intention of snapping some thermal images once they heat up. I then went to design some stuff, and by the time I remembered to go check them, the current had already dropped to around 700mA, so they've already had some time to cool off not running at full power.

Anyway, here's a few shots, but I'll have to do this again some time with the chargers running at full current and having enough time to heat up.

Charger #1, from the Firewheel. Similar "typical" brick as most (67.2V) wheels have, although this one outputs around 67.8V when idle:

mIMKuR8.jpg

Led-side

8Azchj4.jpg

Opposite side

 

Charger #2, came with KS16S:

QBK4ssH.jpg

LED-side

lvwWV0J.jpg

Opposite side.

The Firewheel charger runs a bit hotter, could be that since it has somewhat higher output voltage, it outputs a larger portion of the total current going to the wheel...

 

 

 

 

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The chargers that came with my KS-16S and KS-18S both do not get very hot. Here on the picture the hottest spot is 53˚C, but the average surface temperature is about 43˚C. At the time of measurement, the charger was consuming 130-140W from the mains.

WhatsApp Image 2018-05-21 at 22.04.29.jpeg

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Hello, all,

 

New rider, just got a King Song 14S from Jason at EWheels.  Charged it once already with 80% as my target.  I was concerned to say the least at how hot the charger got.  I could smell the plastic, although nothing had burned.  I'd say about 130-140F.  Hot potato, but not impossible to hold.  Anyone use the 5A quick charger/  Does that get hot?

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11 minutes ago, Designated_david said:

Hello, all,

 

New rider, just got a King Song 14S from Jason at EWheels.  Charged it once already with 80% as my target.  I was concerned to say the least at how hot the charger got.  I could smell the plastic, although nothing had burned.  I'd say about 130-140F.  Hot potato, but not impossible to hold. 

The "usual" plastic bricks seem to run at least somewhat hot, I have one 4A charger that actually has a fan to keep it cool (still in plastic casing though). So far haven't had any of the ~150-200W passive cooled bricks fail on me, but I did remove one from use after it started making some extra noise... I think it's still somewhere in the electronics scrap box awaiting further inspection :D  In general, I remember one case where the plastic had actually partially melted on someone, but it doesn't seem common.

 

Quote

Anyone use the 5A quick charger/  Does that get hot?

Don't know about the current ones, but my friend bought the fast charger with his KS16B back in 2016 from Jason (back when he operated in UK). At least that one had aluminum casing being used as the heatsink for the hot parts, and metal, not that surprisingly, conducts heat much better than plastic. I once adjusted it a bit as the voltages were off, but never run it with high load, but I'd imagine it runs much cooler (there's better heat conductivity, temperature-activated fan and larger surface area to dissipate the heat).

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57 minutes ago, Designated_david said:

Hello, all,

 

New rider, just got a King Song 14S from Jason at EWheels.  Charged it once already with 80% as my target.  I was concerned to say the least at how hot the charger got.  I could smell the plastic, although nothing had burned.  I'd say about 130-140F.  Hot potato, but not impossible to hold.  Anyone use the 5A quick charger/  Does that get hot?

The quick chargers have fan(s) and run cool. I have the EWheels Gotway 5-amp quick charger and it runs cool. All of my standard 'brick' chargers run very hot.

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Finally remembered to take new shots from the chargers, this time they'd been under full load for about an hour:

Firewheel charger top-side (the one with the LED):

hX8MsQs.jpg

Underside (label):

ShabivR.jpg

Goes up to around 70 degrees C, which seems somewhat high, but I've been using it for years without issues.

 

KS16S original charger (top-side with LED):

eWl4ilK.jpg

 

Bottom-side:

kiwW8pk.jpg

About 10 degrees cooler hottest spot than with FW-charger, might partially be caused by the slight difference in output voltages (67.8 vs 67.2V), so the FW-charger might be outputting a larger portion of the total current. Also the hot spots are in different places, so likely the innards are different between these two despite similar plastic cases.

Bonus-picture, Charge Doctor V2:

dpCMSSV.jpg

 

 

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21 minutes ago, Hunka Hunka Burning Love said:

:w00t2:  Man I need me a FLIR heat camera.  But you know if you thought of a special usage for it, someone else has already beaten you to it on the internet.  :crying:

 

  Reveal hidden contents

 

IMG_4309.jpg

Too far?  Am I gonna be in trouble again?  :whistling:

 

 

That's a very hot and weird finger you have there.. :blink:

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Thought you all might like to know, I had the 5A quick charger with the fan included on my order from EWheels, but Jason and Nick are saying they are out of stock, I'm still waiting for mine to ship.  The fact these chargers get so hot is concerning, to say the least. 

No one's house has burned down because of these, have they?

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I have a 5A charger that I used to use with my generic wheel.  Ya, I know, overkill and kinda crazy.  :rolleyes:  I cranked it down with the adjustment pots to a lower charging rate so it worked fine.  The unit itself had an aluminum casing with a pretty good fan so I didn't see any heat issues.

If the plastic ones are getting really hot, one could try placing them on top of a plastic frozen cooler pack to help draw some of the heat away.  Heat tends to shorten electronics life. These chargers are likely a third party sourced item for the wheel makers so they tend to be cheaply made to be just "good enough."  I never charge my wheels overnight or unattended.

If you want to do it over-night maybe placing the charger and wheel in a steel garbage can or box with a vented lid and a smoke alarm inside would be prudent.  Chargers that fail usually just end up not putting out proper voltages.  I don't recall an EUC one catching on fire.  There were a couple cheaper wheels themselves that have caught on fire so best to use caution.   Even big brand name items have had issues.   Samsung Galaxy Note 7 anyone?  :whistling:

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I took a chance and bought the cheapest 5A charger from Ali. Large plastic box that weighs like it was empty, but measures and functions correctly. Fan is a bit noisy, but this thing doesn’t heat up at all. It doesn’t even blow out hot air.

Still won’t leave it on for the night or when I’m away.

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12 hours ago, Hunka Hunka Burning Love said:

If the plastic ones are getting really hot, one could try placing them on top of a plastic frozen cooler pack to help draw some of the heat away.  Heat tends to shorten electronics life. These chargers are likely a third party sourced item for the wheel makers so they tend to be cheaply made to be just "good enough."  I never charge my wheels overnight or unattended.

I didn't either, until last night... I put the wheel charging late in the evening, not meaning to even charge fully, checked on it a couple of times, and reminded myself to unplug the chargers after taking the dog out. Before heading for bed, I had this nagging feeling that I've forgotten something. "Oh right, I didn't put the antibiotic drops in my eyes yet, that must be it". So put those and then went to sleep...

I remembered the wheel the first thing this morning I woke up. The Firewheel charger actually outputs around 67.8V instead of the usual 67.2V. Never bothered to open up the unit to adjust it, as it hasn't been a problem, as the voltage has never gone above 67.2V through the Charge Doctor, but I've never kept it for 8+ hours on the charger after it's full. Checking the Charge Doctor, the voltage was at steady 67.2V, 0.00A running and both the chargers were cold. Phew... Not planning to do that again! On the other hand, at least the cells should be now certainly balanced  :D

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Stock charger heats up a lot and is fine only for charging at night (when you're in no hurry at all). During the breaks in middle of the day, when wheel needs to be charged fast, I use 7A charger (it actually outputs 7.4A 67V), since LG MJ1 cells can take 1.7A by the spec, that'll be 6.8A for 4 parallels of KS16S battery. Battery is charged by 1% each minute approx. without any issues so far.

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7 hours ago, EZhel said:

Stock charger heats up a lot and is fine only for charging at night (when you're in no hurry at all). During the breaks in middle of the day, when wheel needs to be charged fast, I use 7A charger (it actually outputs 7.4A 67V), since LG MJ1 cells can take 1.7A by the spec, that'll be 6.8A for 4 parallels of KS16S battery. Battery is charged by 1% each minute approx. without any issues so far.

Faster charging stresses the cells more than slower, and for most cells it's said that "1C" -charging speed should not be exceeded (that is, maximum charging amperage is the same as the nominal cell capacity). 7A is still nowhere near that (0.5C with 14Ah total capacity, 4 parallel 3.5Ah series, so 1C would be 14A), only thing I'd be worried is whether the charge port and wiring can handle that in the long run. GX16-3 is rated for 5A or 7A max., depending where you look, either way, it's close to max (or above). Of course if the port can take it and nothing starts heating up too much (or melting ;)), then it's not an issue. Haven't checked the charge port wiring, but likely it isn't very strong gauge, at least 1RadWerkstatt used to add thicker wiring and secondary charge port for faster charging for some battery mods/high wattage chargers (up to 8A or 10A, I think) so things don't burn.

LG MJ1:

  • Nominal capacity: 3500 mAh
  • Minimum capaciy: 3400 mAh
  • Average voltage over discharge: 3.635V
  • Standard charge: .5C
  • Maximum charge current: 1C
  • Maximum discharge current: 10A
  • Cycle life: 400 cycles

https://batterybro.com/blogs/18650-wholesale-battery-reviews/40773059-new-lg-mj1-18650-battery-review-3500mah

The cycle life should be higher than 400 cycles if not always riding all the way to empty and charging all the way to full. And KSs start the battery warning at 50V, which is still (slightly) above the 3V per cell "standard" empty voltage.

 

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1 minute ago, esaj said:

Haven't checked the charge port wiring, but likely it isn't very strong

Wiring heats up when charged with 7A, so I plan to repace it with thicker wires and sturdier connector to circuit some day, but anyway, nothing bad has happened so far for several people who use 7A chargers for KS16S. A generic 5A charger is safer, twice cheaper and twice lighter option while giving good charging speed.

1C is overkill and will degrade cells, not to speak of weak wiring etc, so no, don't want my wheel to go on fire randomly.

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  • 2 months later...
On 5/15/2018 at 7:51 PM, novazeus said:

 i don’t remember how i set the chargedoctor ie amp cutoff or voltage cutoff.

Adjustement

Enter adjustment mode by holding the button when powering on. 1) mode auto-shutdown, threshold adjustment : button hold < 5s 2) mode voltage & current calibration : button hold > 5s

1) Adjustement of auto-shutdown threshold

Top led displays current parameter. With no button click, the screen is cycled through 3 avaibles pa- rameters every 2s. Any click holds up the actual parameter 6s for adjustment before the cycling restarts. Adjustment mode is terminated and the CD gets back to normal mode if no click for more than 10s.

3 available parameters:

Auto : auto-cut
Pr1 : parameter 1, display o
ff at auto-cut
Pr2 : parameter 2, auto-cut mode by current or voltage

 “Auto” : auto-shutdown mode. Bottom led displays the shutdown threshold. When the threshold is reached, current is cut by the CD and the charge session is ended (I=0.00A). The threshold is in- cremented by 0.1A steps (auto-cut by current mode) or 0.1V steps (auto-cut by voltage mode). Hold the button for fast then ultra-fast increment. Voltage and current threshold are stored in separatenon-volatile memories.

Important: disabling auto-cut can not be done in “parameter mode” only in normal mode (see above).

 “Pr1” : parameter 1. Value = 1 => deep standby mode with Led display off at auto-cut. To power on, click button or disconnect/reconnect the CD.

 “Pr2” : parameter 2. Available values, “dn A”, “up V”, “dn V”

dn A : down A, auo-cut when charge current is below thresh- old. Default mode at first use.

UP V : auto-cut when charge voltage is above threshold. This mode generally allows more ac- curate auto-cut, to be used on big batteries (>560Wh) when auto-cut by current doesn’t have enough resolution.

dn V : down V, auto-cut when voltage drops below threshold. To be used only for discharge tests.

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