Defective rechargeable floodlight

Other Types of Lights LED Spotlights
7

Thanks for the help!
I’ll check in on how to measure the Amps. I’m not that into electronics so I’ll have to reread your steps a couple of times and figure out a way of putting a load on the batteries as using the converter and hooking it up to the LED doesn’t seem to work

Here is a photo of the original connector.

Not much to see again. But it is a 3 pin connector, but only 2 of the 3 pins are connected (was like that when I opened it and no other loose cables)

The red wire from battery with black wire from switch to 1 pin. The black wire from battery and white wire to converter on a second pin.
And then theres a red wire from switch to the converter.

I charged the battery some more and after half an hour it showed full again. I could twist and turn and push and tinker all I want, it keeps saying full again. Measuring a nice 12.5V

The original runtime of the battery is specced as 4 hours. According to my friend it does have a runtime of about 3-4 hours.
It was sold as 100W, but it could easily be 50W. Although it is bought locally for a hefty price, I’m sure it is just some chinese import.

8

I don’t have any 12V 10A power supply on hand. Will search through my junk to see if I can find anything.
With a 12V 2.25A powersupply I get a reading of 0.68A (If I did it correct)

With the battery pack, again a quick flash and nothing. Multimeter couldn’t make a reading.

Please note, all my multimeters and cables are cheap chinese stuff. Not sure how accurate they are.
My normal measurements only consist of yes this battery is still full, yes this light socket still has power on it, yes it beeps so the connection is okay :blush:

Edit:
Also tried my 32V supply directly on the LED again, is an old HP printer supply with 32V and 940mA output.
Measurement 0.98A so I assume my method of testing is correct

9

Connect the three LI-ION 18650 (Button on top) cells in series.
But be careful, an incorrect connection can burn the driver.

If it works, you need a new battery pack; if not, you need a new driver.

Why am I interested in runtime.
If we have a 100W LED, a driver with a constant current mode (I’m not sure I need to check), and a 18650 3000 mAh cell.
With a 3s2p circuit, we get a 12.6v 6000mAh battery pack.
When consuming 100W from the battery, we get a runtime of 35-40 minutes. Therefore, I doubt that it is 100W.

10

Alright.

Disconnected everything. Directly hooked the batterypack to the driver -> Single flash of light, voltage on battery end 12.7V, voltage on driver output: 12V

Couldn’t find a 10A power supply but found a 6A. Hooked that to the driver. LED works, drawing again 0.68A.

Freshly charged 3 18650 batteries from myself, connected them in serie -> Single flash of light, multimeter not fast enough to display any current reading.

So defective driver? But why does it work with a power supply?

Some more photo’s in case it might help.

11

If the driver is defective, what should I buy to replace?

12

How confident are you in your batteries?
Are these the ones that came with the light?
If it works on the power supply, it should work on the batteries.
Pull the pack apart and see if one cell is different than the others, when trying to power the light.
A cheap light might not have any balancing and one of the cells in the pack may be bad or way out of balance with the rest.
All the Best,
Jeff

Oops, just saw that you tried some of your own cells.
No clue why it works with a power supply but not batteries.
Very odd.
PS try it with a 12v lead acid battery, like a car battery if you don’t have any smaller ones.
See if that has juice to light things up.
PPS, you might try it with 4 cells in series. Perhaps the boost driver is not quite getting enough voltage to make thing happen.

There are all sorts of adjustable boost driver on Amazon and ebay. just look for one that has enough output voltage and current.
For example, and I actually know nothing about this brand or seller.
https://www.amazon.com/DZS-Elec-Converter-Adjustable-Regulator/dp/B07L6F6S6S/ref=sr_1_3?crid=2844YDXKM9H4V&dchild=1&keywords=boost%2Bpower%2Bsupply&qid=1589903572&sprefix=boost%2Bpower%2Bs%2Caps%2C255&sr=8-3&th=1

13

Thanks for the input.

Tried 4 cells, it took a second, like it needed to charge but it turned on!
Tried 3 cells and only the single flash again.

Tried a 12V lead acid battery (12AH, not for a car)
Bright flash and nothing. Battery was at 13.2 volt, output of the driver was 12.75.

So can we conclude the driver is defective?
Still don’t understand why a 12V power supply is able to drive the light but 12/13V of batteries does not.

On the amazon link I see they have a 250W and a 600W. Seeing as the light is 100W, or as found out probably even just 50W. Would the 250W be enough or do I need to look for the 600W?
And if enough, would this one be good? https://www.tinytronics.nl/shop/nl/spanning-converters/step-up/dc-dc-verstelbare-step-up-boost-converter-150w
Input voltage: 10V-32V
Output voltage: 12V-35V
Maximum input: 16A
Maximum output: 10A, No-load stroom 25mA
output power: 100W (passive cooling in 20°C air), 150W with a fan on the heatsink(active cooling in 20°C air)
Conversio -efficiëntie: 94%

And as a follow up question. This one was encased in some sort of sillicone. Do I need to do that again? Would a load of hot glue work?

14

there is nothing wrong with driver, at least not in a sense that it is defective, it works off 4 cell, it just needs more input voltage for given output, you can replace the driver if you want, ot rewire cells to 4S it would be a good idea to include balance board\pcb, it will probably work some time with no balance board, and no pcb, but i would not rick it, especially with unknown brand cells.

as far as why power supply worked, probably because it has more than 12v, idk what ps you used, but most ps today will give you rated voltage under rated load, if load is lower it may give you more voltage

15

If it works on 4 cells and doesn’t on 3 it must be the batteries.
Probably a cheap poor quality battery pack.

16

The power supply I tried was 12V 6A, just measured voltage without load, 12.4V

The battery pack fully charged gives 12.7V output.
The lead acid battery measured 13.2V under load.

Rewiring the batteries doesnt sound like a good option.
The included charger wouldn’t work anymore and my friend isn’t going to know how to handle things I guess.
Don’t know if I’m confident enough either to do that.

17

Sorry to be absent for a long time, a lot of problems lately.
Perhaps the driver was overheated, and some components left their nominal values, so it does not work now from 12v.
To find out, you need to remove the compound and take some measurements, but it will be difficult and I’m not sure if this will help you.

It looks like in this photo we see a driver power of 35 watts.
This was the AD-DC version of the driver. The photo shows that there are no 2 diodes out of 4, and the remaining two diodes protect against reverse polarity.

And I was mistaken, I thought the battery pack consists of 6 cells (3s2p), but it looks like there are 12 cells (3s4p).

I took some measurements of boost converters.

1.

Input voltage 8.5-40v
Output voltage 10-45v
Output power is 250 watts.
This is a convenient version of the CC CV boost converter; it is assembled on an aluminum plate. It is similar to the MCPCB for the LED and it can be glued to the back cover.
I loaded it at 35 watts, and it works well in the range 8.5-14v. But it turns on very unstably at a voltage below 8.2v and at the same time it gets very hot.
If we turn it on when the voltage on the battery is 8.5-12v, it works fine and discharges the battery to 7.5v. But if we turn it on at a voltage of 7.5-8v, it can fail.

2.

Input voltage 10-30v
Output voltage 10-35v
Output power is 150 watts.
Good CC-CV boost converter with undervoltage protection. With an output power of 35 watts, it does not heat up, it works stably up to a voltage of 9.80v. At a voltage of 9.80v, protection is turned on, and the output power drops to 30-40%. Meanwhile, due to the low load on the battery, the voltage on it rises to 10.3-10.5v and the converter continues to discharge it to 9.80v.
But there are two problems:
1 Fine adjustment of output voltage required. The converter maintains a constant current, but if you set the voltage higher than necessary, it does not work stably.
2 It is also slightly unstable in protection mode.
from undervoltage. There is a slight tremor of light.

3.

The boost converter in your link is identical to the previous one, but it has no current regulation, only voltage regulation.

Most BMS battery boards have undervoltage protection at 2.5v per cell or 7.5v for three cells connected in series.
The first converter can drain the battery completely, and you will have maximum run time, but turning it on below 8.5v can burn it.
The second converter has some problems, and does not completely discharge the battery, up to 9.80v (3.26v per cell), but it is more suitable for you.
The third converter, I recommend you only if you have not found anything.

some links

https://www.tinytronics.nl/shop/nl/spanning-converters/step-up/dc-dc-verstelbare-step-up-boost-converter-150w-met-stroombegrenzer

https://www.tinytronics.nl/shop/nl/spanning-converters/step-up/dc-dc-verstelbare-step-up-boost-converter-150w

18

Thanks for the input.
There are 12 cells indeed.

Going to try the second one.
Rather have the light turn off before completely empty than to burn stuff. And since the driver is enclosed in the battery compartment cooling is an issue.
My friend is using the light while working. Don’t know if he will be attentive enough to notice the light needs to be turned off because he works with multiple lights at once.

What would be a nice voltage to set it on? Since the led runs from 30-36V. Lifetime is more important than brightest output so putting it on the lowest as possible? Or a little higher, at 32V so it has some margin of error?

19

With an adjustible boost, you might let heat be your guideline.
Crank it up so the light is bright enough without producing too much heat to cook things.

I wonder about the battery pack and charging.
It might be worth a look to see how the cells are aranged.
And if any cells seem out of ballance.
Looks like you are getting close to solving the puzzle.
All the Best,
Jeff

20

I think your friend will notice that the light is discharged.
The output power of the driver drops to 40% at a voltage of 9.80V. Then the brightness continues to slowly decline and can reach up to 20 lumens. Such brightness no longer illuminates anything, and it will be clear that it needs to be charged.

A few steps to configure the driver.

The driver has 3 trim resistors on board
“CC” (Voltage Regulation)
“CV” (current control)
“UVP” (Adjustment of undervoltage protection)
First you need to rotate all adjustment resistor counterclockwise 20-25 turns, at the end you can hear clicks.
Connect the driver as shown in the picture.

Turn the “CV” adjustment resistor clockwise and adjust the voltage to 32V.
Then connect the driver as shown in the picture.

Turn the “CC” adjustment resistor clockwise and adjust the current to 1.10A.
Slowly turn the “CV” adjustment resistor counterclockwise until the current drops to 1.08A, then slowly turn clockwise until the current rises to exactly 1.10A. At this point, the adjustment is complete.
Thus, you set the power to about 35 watts.
I think it will be optimal for runtime and brightness. If the brightness is not enough for you, you can increase the power, but I do not recommend increasing it more than 50 watts.

A few points:

  1. I do not recommend using, or turn on the light while charging.
  2. Do not enclose the driver in silicone or hot glue. You need to drill 4 holes and fix the driver to the screws, or wrap it with something and fix it with silicone to the back cover as the batteries are fixed. I recommend checking the silicone seal on the back cover.
  3. In the undervoltage protection mode, the light will not behave stably (nervously), this is normal.

I hope this helps you.
Waiting for the result…

21

Thanks for the input again!

The light works! But don’t know if it works as supposed. Don’t know how bright it was before and if this is what it’s supposed to be but the numbers aren’t right.
I can’t get a higher Amp output of 0.45A

I did as suggested. Dialed it in at 32V without load. Connected the light, it starts at 0.45A and no matter how far I turn it it stays there. The voltage stays at 28.6V at the output leads. I turned it all up until the clicks but that’s the maximum I get.
I measured voltage at the input leads and it’s at 9.8V. So I assumed battery pack was defective after all and it went into protection right away. But then I measured at the battery pack itself during the same time and it’s at 11.9V
To rule things out, I connected it to the 12V lead acid battery, and the 12V 6A powersupply and the exact same results.
Around 0.45A and 28.6V output. A measurement of 9.8V at the input side.
I tried to see if I can change some values if I change the UVP resistor. At some point the light turns off, measured voltage shoots to 12.4V so I assume the undervoltage protection is set at above 12V at that point.

Oh, and I wish I could get the battery pack out, trying to measure cells individually. I tried but it’s so glued to the case I’m not able to get it out easily. No space to get under it. Tried to wiggle to get it loose but no luck. I’m afraid to damages the cells if I try something else. Tried to put a spoon on the side to have some leverage but it looked like I was going to dent and damage the cells if I used any more force.

22

Try to pry it off with a hard plastic item, for instance an old creditcard or old membership card or equivalent.

23

Yes you are right, the driver works in protection mode.
Turn the “CC”, “UVP” resistor fully counterclockwise until it clicks. Connect to a 12V 6A power source or lead battery and try increasing the output current again.
And do not short-circuit the driver output.
With an input voltage of 12V and an output power of 35 watts, the input current of the driver is about 3.20A. This should not be a problem for a good lead battery or 12V 6A power supply.
The minimum value for undervoltage protection is 9.80V, you cannot set it lower, but you can set it higher using the “CV” resistor.

To measure the cells in the battery you need to remove the blue film. In this case, it is not necessary to tear off the battery from the cover, you can cut the film gently and remove the cells.

It’s strange.
I began to doubt, maybe the old driver is working.

24

Just tried again. Same results.

12V 6A power supply.
Dialed everything CCW until clicks.
Connected PSU, ramped up voltage to 32V, measured voltage at input 12.1V.
Connected light. Slightly turned up CC, lights goes on at 0.4A, immediately voltage on input side drops to 9.8V.

Am I unlucky? Do I have ordered a defective driver? Should I just give up :confounded:

25

This is really weird.
Can you show the photo:
new driver (on both sides),
connection photo
12V power supply
Lead battery.

It’s too early to give up

26

@RD, your English is perfect. Most of us don’t speak 2 or more languages, so you are doing great.

@johnny, you have done a great job at troubleshooting. Considering all the strange results i would recommend a simple approach to start at the input and work to the output.

0. Remove all the goo and glue around the connectors and switch and any other place in which the wiring solder joints are covered. Inspect and touch up any cold or broken solder joint. Replace wires if necessary to ensure good path and eliminate the wiring or joints as a culprit.

1. Slice the blue film so you can verify the configuration of the cells, to measure and compare the individual cell voltages (looking for laggards), to load test and check capacity of individual cells, and to look for some sort of BMS board for the cells.

2. Rebuild the pack (replace defective cells) and BMS as necessary to eliminate that as a culprit of the problems.

3. Charge the pack and measure/verify the voltage and current while charging, if possible. Measure the pack voltage after charging to verify that the charger is working properly, no over or under charge, cuts off at limit, etc. Eliminate the charger as a culprit. [and like RD said, don’t try to run any load from a charger, not designed to work that way and possible to damage something.]

4. Test the driver and LED with this known-to-be-good pack. If the results are flaky with good solder joints, wiring and pack, then the driver is suspected as a culprit. Repair or replace.

5. Now the light has been rebuilt from front to end, and should give good service, especially considering the price.

Here is just an example of some various drivers: open boards, enclosed, and waterproof.

Good Luck and Enjoy.