Batboard

I went to an FD for a repair lately on an engine and while I was there they asked me a question about their Litebox chargers. They have 3 streamlight Liteboxes that are plugged directly into the wall via the supplied wall-wort transformer.

After a 1 1/2 years of use, both power supplies bit the dust. For the heck of it I ripped one apart and found the boards in both were melted. They were so identically melted that it was weird. So we replaced power supplies. I figured after so much charging use that they just got hot.

Nothing else, including 2 other chargers plugged into the same outlet was destroyed, which kind of eliminated the idea of some sort of surge or something destroying.

So the new ones are there working fine, lights charged fine...a week later, bam they are fried again. I check mounting plates for shorts, ect...nothing...contacts are clean...ect...ect... I just dont see these many transformers biting the dust so soon, or 3 mounting plates being defective all at the same time ethier.

One thing is that they have all 3 chargers plugged into a 6 outlet surge protector that has sustained no damage. Could this be the culprit?

BTW ...these lights are rotated from the engines to the bay pretty often, so I dont think the lights have anything to do with it...

Anyone else every had the same problems...Should I try removing the power surge protector and adding more outlets on the circuit?

Thanks...Nick

I'd definetly email Streamlight about it.

I emailed Pelican asking about coverting a home unit to the car and they told me they are sending me the car kit.

If it were my place, I'd definetly send an electrician to check those outlets. Sounds like they are being allowed to draw too much current or something. It's obviously not a defect in several chargers.. that leaves the outlets.

I'm not familiar with them, but i wanted to comment on this.

First of all, you said that the first two that died looked the same inside, which component/components were actually damaged?

I take it they are just wall wart dc adapters that we are referring to here?

One thing you might want to try, check the voltage at the outlets on the surge supressor. Sometimes they fail but keep passing power. In one case i had a wall wart that was always getting hot as heck, it had a fixed voltage regulator in it and the surge supressor it was plugged into was only supplying around 60-80 volts, it would change if you smacked the case. I unplugged the surge protector and plugged the power supply into the wall outlet direct and it didn't get hot ever again.

If nothing else i would like to see a picture of the failed power supplies if possible, would be nice to know whats making them fail in case i ever come across something like it again.

I will get some pics and more information this evening and post.

Thanks!

i would like to comment on this, as i had similar problems w/ the wallwarts for the HT1250 line of portables.

Think now, about what you are doing for these radios (lightboxes in this instance). In our trucks, we were running the wall outlets off our inverter when the engine was running & passthru utility power when it was shorelined. After careful inspection - the inverter was putting out (our resident EE got into this one) nothing close to line quality sine wave power ** despite the fact the manual touted it was "clean sine wave" output" (and this was a Vanner inverter too!!) ***. So as best as we could figure, the wallwart was going bonkers trying to reduce that power down to a radio friendly output, and consequently overheated and melted the innards. Not to mention the efficiency factor between the mechanical inversion of engine power to 120, and then the wall wart inversion loss from 120 back to 12 vDC. Now if you compare this to the near nothing loss of getting the 12vDC wiring harnesses for the lightboxes, you can only see why you are getting so much heat, and consequently damage.

We ended up putting all four of our line vehicles thru the same tests, and the oscilloscope's all showed the same crappy waveform from the inverters in the trucks...thus smoking all the wallwarts on the vehicles. This was essentially deemed the culprit, because the single standby unit that spends 99% of it's life on the shore line ***w/ passthru line power to the interior outlets!!!*** had some nice cool normally functioning wallwarts on its portable radios! With this coroborrating evidence in mind, we went and wired the portables directly to the 12 VDC buss in the trucks and never had a problem again.

I would bet a million bucks that you can solve this problem by replacing the 120 VAC chargers on those boxes w/ the much more efficient 12VDC charging units.

KuhnElectronics wrote:I went to an FD for a repair lately on an engine and while I was there they asked me a question about their Litebox chargers. They have 3 streamlight Liteboxes that are plugged directly into the wall via the supplied wall-wort transformer

Nick,
The factory wall wort only supplies about 500 Ma. If the lights are deep cycled (run down to the point of dimness), I'll bet that you are pulling more the that during the initial charge cycle.

BTW, Don't rule out the lights themselves - the 2 pin connector is soldered. If it's been abused or the wall wort is plugged directly into the light, it contributes to the connector failure. I routinely change the pigtail if the battery is being changed.

Martin