hi folks. i live in upstate south carolina and work in information technology. first started paying attention to flashlights when my daughter and i started walking our dogs at night. we started with a couple of cheap, noname, single 18650 lights from amazon, which fell apart pretty quickly. not knowing any better i went back to amazon and got a couple of 2x26650 lights that looked sturdier. they say garberiel fg1192 ce on them, but they look like a bunch of other lights there. they worked well for a while, but after a couple months the battery life started dropping. at first we could take our 10 - 15 minute walk every night for 10 days or so before the last blue light started blinking and they ran out. but that got shorter and shorter and now after 2 days they’re likely to die.
at first i suspected the batteries were going bad, maybe low quality or used/recycled, so i ordered a set of orbtronic 5500mah cells, from orbtronic. that didn’t really seem to help, after a full charge they’d still only last a couple of nights. i got an xtar vc4sl and put the orbtronics in it in grading mode, and after discharging they took a solid 5500mah before they showed full. and the original batteries that came with the lights also seemed to hold pretty close to what they’re supposed to. but i noticed that when i put them in the charger in regular charge mode, they’d only take about 700mah or so before the xtar said they were full. so it seems like the lights are saying the batteries are empty when there’s actually a lot of juice left in them. that’s not how they worked when i first got them, so i’m wondering what has changed.
only explanation i’ve come up with is that internal resistance in the light has increased, maybe from cheap electronics degrading or corrosion on mechanical contacts, so that it takes a higher voltage from the battery to drive the light. i’m hoping some of you who know a lot about this stuff can share some insight. is this just to be expected from cheap lights? is there any way to restore them to original performance?
after finding blf and reading up a bit i’ve gotten a couple of sofirn lights that seem to be holding up well, so we’re not walking around in the dark. but the garberiels seem pretty solid, other than running out of gas before they should, and the zoom thing is handy sometimes. it would be great if there was a way to salvage them, otherwise i’d like to avoid having the same problem with their replacements.
I’m not entirely sure what could be causing the issue you cite, it could be degrading electronics but i think you would notice a brightness difference if it was.
Have a browse around the forum and you’ll see that the LED, driver, and switch are the main parts that could be changed to salvage the body, which i would call a host.
How easy/feasible it is to replace those parts depends on the specific torch. The switch, for example, is sometimes held in place by a retaining ring which can make it relatively straightforward to replace, but sometimes it is glued in place which is trickier. (Or maybe not depending on your skill set. )
It’s irrelevant how much the cells “take” when charging, as you need to see how much they supply on discharge.
I could keep the nozzle attached to my car with the little trigger-thingy locked, and dump 50gal of gas “into” it, with 40gal ending up on the ground, and that doesn’t indicate how big my car’s tank is.
Check each cell individually. If they’re 2 cells in series, the runt of the litter is going to determine how much “capacity” the series battery has. If left to run down below Really Bad Low Voltage, that runt could be permanently munged.
thank you, don, that thread is interesting. sounds like maybe most of the problems are with nimh batteries. i only have li ion, and only charge 2 at a time. i’m using the qualcomm qc3.0 5v/3a 9v/2a ps orbtronic sells as the recommended unit for it. i did not change the cable, though, that’s a thought. i guess i’d be more suspicious of the charging system if it didn’t appear to do exactly what i expected in grading mode. it goes through the whole discharge process, then starts charging and stops with a reading of between 5460 and 5600 mah. that’s why i believed it when in charge only mode it only added ~700mah before saying the batteries are full.
Is this the 100000 lumen version or the better 250000 lumen version?
Either one should be good for looking in dark holes. After dark some night I would go out into the backyard and dig a 6-ft hole. Use the light to inspect the bottom of the hole. Then drop it in. Then bury it.
Do not buy lights that use two or more batteries.
the 250, obviously. duh. now i don’t usually need all quarter million lumens, unless i’m using it for welding or propulsion. so i split off the extra and shine it into a mirrored box to save for later. it’s pretty simple, really, you just have to close the top real fast so the light doesn’t have time to bounce out.
There are plenty of multi battery lights that are completely safe. Q8, SP36 etc…
As long as the batteries are matched and good quality.
What you don’t want is a light with built in charging and the batts in series.
Since you are charging externally - no problems.
Protected cells take the worry out of most any light.
All the Best,
Jeff
What you are saying doesn’t add up. You need a multimeter and you need to measure voltage at various stages. Measure voltage at whatever stage they’re at now of each individual battery. Run a charge and discharge and charge and discharge cycle two times with at least a 10 minute rest (longer is fine) at every stage and measure voltage of every battery at the end of every stage and right before you start the next stage. And measure voltage of both batteries when you pull them out of the lights when it says they are fully discharged. Are you trying to run these at the highest setting? Don’t. And number or label each battery so you can keep track of them.
If that charger will allow you to look at voltage without charging you can use that.
IMO, if the capacity and IR test close together, a pair of batteries is fine. Agreed with numbering them though - shuffle the order they are in the light in, and check if one is consistently ending up lower or higher than the others.
Also, the more unsure you are about your series batteries, you can just stop at higher voltages. In general whenever I first use a series set I’ll stop shortly into my first go with the light and check how the batteries are.
Also, when it comes to multiple batteries, if they are in parallel it’s completely fine to charge without a BMS as the voltage becomes equalised across all the parallel batteries. The charging IC will use constant voltage mode, so cuts off when all the cells reach full. All Sofirn sodacan lights use parallel batteries.
The one thing to watch out for with parallel is one battery with a high self discharge, which won’t be as obvious as the other two will recharge it as it drops - you can check that by just disconnecting the batteries so they are no longer in parallel (depending on the design of the light, can mean just mechanically locking out the light, or can mean removing batteries entirely and putting them in a case) then checking the voltage of each cell before putting them back in the light/charger.
That said, I think you misunderstood here. They were wondering if their single cell light was performing worse because the LED’s Vf had increased (which doesn’t really happen like that) so the single cell wasn’t driving the LED as hard. In general that doesn’t happen though. Not implying that light used series batteries.
I have many lights with large numbers of batteries in both series and parallel but I wouldn’t trust a $5 zoomie with series li-ions either - but it is not true to say that there are no lights that handle series batteries responsibly.
This was my thoughts too until recently- my LT1 (4P 18650) seems to be draining cells way faster than parasitic drain should be… I assume one is failing and the others keep trying to “charge it”, quite scary… I think this is the gist of what wolfgirl posts here:
Please consider the context.
Many/most new members here have very little knowledge of lithium-ion batteries. Most do not have multimeters. No one here would suggest that new members go to Amazon and buy no name brand lights making outrageous claims with questionable batteries. None of these new members need lights with multiple batteries to walk their dog.
- but it is not true to say that there are no lights that handle series batteries responsibly.