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 > LED light and 12v Voltage? UPDATE-OOPS!/Got Kohrees too.

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BFL13

Victoria, BC

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Posted: 11/13/20 03:40pm Link  |  Quote  |  Print  |  Notify Moderator

In the garage I have an older 100amp PM3 on a battery at 13.5v with a 400w MSW inverter also on the battery supplying the stick house internet modem as a UPS.

Meter on hz setting says 59.75 on the inverter and 00.00 on the PM3 DC output terminals. In the MH, the 75amper at 13.5 has 00.00 hz on the DC terminals. Readings jumping around everywhere in the PSW inverter GFCI outlet. Get 59.94 in the MH outlets from the stick house shore power.

Can't test the 55 amper in the TC that has the LED for now, as the TC is away for dog training.


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MrWizard

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Posted: 11/13/20 07:46pm Link  |  Quote  |  Print  |  Notify Moderator

That should work, if ripple test comes up blank null void
Try the suggested fixes, or get some different fixtures
I took this picture of battery charging data, just minutes ago before making this response
[image]

* This post was edited 11/13/20 08:03pm by MrWizard *


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Gdetrailer

PA

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Posted: 11/13/20 09:39pm Link  |  Quote  |  Print  |  Notify Moderator

ktmrfs wrote:


while this may solve the 14.7V problem, the LED's will likely be quite dim when the battery or charger goes to 13V, or even dimmer as the battery discharges to 12.4 or so.

And LED's for decent life over a variable input voltage range need to be driven by a constant current source to fix the brightness. Not any form of voltage source. LED junction voltage drops as temp rises, and if driven by a voltage source that results in a current increase, more junction voltage drop, more current..... then poof.

The best LED drivers actually use a pulsed current, LED's brightness is a non linear function of current, so higher current = much more brightness. so pulse the current and keep the RMS current to a good value= bright light, long life. Need to pulse the current fast enough not to cause visual flicker. but with the IC's available today not a problem.

all this doesn't come for free, that's why there are cheap LED lights and more expensive ones. You get what you pay for.


Actually you would be shocked just how little change in brightness a few tenths of a volt will cause with LEDs.. Most manufacturers are already running them at max current specs right out of the gate, dropping them a a volt isn't going to show up as a huge drop in brightness.

The "best" LED drivers do not intentionally "pulse" the LEDs, that is the old school method from back in the late 1970s.

Modern day LEDs are much more efficient and brighter that pulsing is no longer needed not to mention the digital outputs of things like clocks and displays was not filtered back and the LEDs pulsed to the switching speed of the drivers then causing the displays to appear flicker when a camera was pointed at it.

Now days the "best" method is to use a SWITCHING CONSTANT CURRENT REGULATOR. Switching regulators are far more efficient and the switching frequency is just above normal hearing range of humans. Care must be taken in the design and layout since they can and do generate RF noise due to the harmonics.. The output is DC and it is filtered well to reduce the harmonics.. So, no, you are not going to find a lot of those pulsing LED drivers unless it is a dirt cheap clock radio using LEDs..

time2roll

Southern California

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Posted: 11/13/20 09:50pm Link  |  Quote  |  Print  |  Notify Moderator

I think mine are rated 10 to 30 volts. 14.7 is just another day.


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MrWizard

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Posted: 11/14/20 04:17am Link  |  Quote  |  Print  |  Notify Moderator

Forgot key note

Voltage range 12 to 18vdc

Kohree, I found mine on Amazon

BFL13

Victoria, BC

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Posted: 11/14/20 06:47am Link  |  Quote  |  Print  |  Notify Moderator

Which one? ( Need dual lamp) Lower cost one says it has a T10 light. Didn't see the voltage range mentioned on a quick look.

https://www.amazon.com/s?k=kohree+12v+le........hree%2Caps%2C228&ref=nb_sb_ss_ts-a-p_3_6

The one with T10s looks a lot like the one I got that stopped working. Not sure of brand till I get another look at it. Mine has about half the lumens--not the same. The LEDs look the same in it though with the cluster ( a wedge pack?)

https://www.princessauto.com/en/detail/1........n-led-interior-vehicle-light/A-p8488702e

The one I got with half the lumens is very bright white light, so double the lumens in the TC (vs a Class A) you would need sunglasses [emoticon]

* This post was edited 11/14/20 06:56am by BFL13 *

pianotuna

Regina, SK, Canada

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Posted: 11/14/20 07:37am Link  |  Quote  |  Print  |  Notify Moderator

BFL13,

There are about 50 solder points in a typical LED. Every one is a potential failure point.


Regards, Don
My ride is a 28 foot Class C, 256 watts solar, 556 amp hours of AGM in two battery banks 12 volt batteries, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.

BFL13

Victoria, BC

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Posted: 11/14/20 07:57am Link  |  Quote  |  Print  |  Notify Moderator

The problem was 6 hours (5pm to 11pm) on the one 3 amp ceiling light cost 18AH. Too much.

I could just get another one like the first and be sure to keep it off when charging at 14.x. Solar is a problem but could swap controllers with the MH. the MH one has adjustable voltage so could keep it under 14 or just turn off solar at 5pm when it is near dusk now anyway. (has a switch on the array side)

One of these Kohrees would be the real answer if I can get the voltage range info of the one to order. Did I miss where it gives the voltage range?

Gdetrailer

PA

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Posted: 11/14/20 09:24am Link  |  Quote  |  Print  |  Notify Moderator

Your Princess auto link didn't give a voltage range, only it was "12V"..

From your link..

"Convenient switch quickly turns the light on or off. Clear LED bulb outputs 324 lumens of light. Durable ABS housing and impact-resistant polycarbonate lens.


Brand Name Powerfist
Item Name Interior Light
Voltage Rating (V DC) 12 V DC
Current Rating (A) 0.67 A
Wattage (W) 8.4 W
Bulb Type LED
Number of Lamps -
Lumens Rating (lm) 324
Average Life (h) 8760 h
Colour Clear
Lens Material Polycarbonate
Housing Material ABS
Mounting Screw
Size (in.) 11-5/8 x 5 in.
Packaging (qty) 1 qty "


Couple of things to me that raise flags..

12V and .67A is actually 8.04W, for it to be 8.4W that would mean the "operating voltage" would be 12.5V.. Running them above 12.5 is going to be a real gamble for sure and indicative of much of the cheapo import stuff..

Second, 324 Lumens for 8.4W is extremely poor, about 38.6 lumens per watt!

Good quality LEDs should be closer to 3W-4W (80-90 Lumens per watt) for that fixture with that Lumens rating..

Granted, they are more efficient than incadescent, but for modern day LEDs they are junk.

Doesn't state the color temp or Color Rendition Index (CRI)but I would guess that it is most likely a rather harsh blueish temp of 5000K-6000K and CRI well below 70 which means a lot of color shift (changes the color you perceive of things around you)..

Oh, another red flag, 8,700 hrs of life? Yeah, those LEDs are way over driven, at least they didn't lie about a "long life" but still the expected life should be upwards of 50,000 hrs or higher..

Personally, if you still have the original incadescent fixture I would put that back in and buy some LED replacement bulbs of much better quality!

BFL13

Victoria, BC

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Posted: 11/14/20 09:46am Link  |  Quote  |  Print  |  Notify Moderator

Yes, using LED bulbs in the old fixture is a good choice. Powerfist is their home brand for lots of their things, so I will check the fixture for any other brand that might be on it.

When Mr Wiz gets back, he can say which Kohree he has that has the good voltage range from that amazon link.

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