Photon Rex Charging Issue

I bought a Photon Rex about a month ago. I found that it would usually not charge at all on a 1.5V battery. It DID charge on a DC power supply at 1.5 volts, at the rate of 400ma. It sometimes charged on two D's (i.e. 3 volts) and sometimes not. It was NOT an issue with the contacts; the light was defective.

I sent the light back to Photon and they replied in a form letter that you folks might like to read. I consider their response good customer service.


"...we have found a charging issue with the code in the circuit board of your Rex light. The issue only affects the light in deep discharge. If your light is drained all the way it will only start a charge with a 3 volt battery (CR123). It may take a few minutes for the LEDs to start blinking and indicate the charging process has begun. If you do not let your Rex drain all the way you can use 1.5 volts (AA, C, D cell)."

"When we receive our new shipment of Rex we will send you a replacement at no cost. Enclosed is a gift for your inconvenience and thank you for your patience in this matter."


They sent me ***a working*** light with a full charge... along with a new "X-Light-Micro" as compensation. I'm expecting a NEW 100% working Rex soon. Sure, I'd rather the first Rex was 100%. But the Photon guys DID take responsibility and they're doing right by me.

I figured I'd let you guys know about this should you be experiencing the same problem.

W.

Does the Rex not have built in over-discharge protection? Since it uses a LiIon cell you'd think that they would include something like that? I hope so because I love the UI so much I was about to order one finally. I'd rather have a Proton if it weren't for that dam red led!

I have always suspected that there is no deep discharge protection for the ReX since others who have deeply discharged thier ReX's have had issues. I have never ran mine down very low and charge it even if it has had little use. It has had many charge cycles.

Their is a lot of information regarding rechargable batteries. Typically, it is better to charge them more often with low discharge than to let them discharge deeply and charge less often (except for cases with NiCads). You will get more cycles if you do not let the battery discharge very low than you would if you discharge the battery to almost dead.

Thanks for the info from Photon.

Additional info: Since Lithium Ion batteries will be ruined if they are discharged below acceptable levels (ones that do not have a low discharge protection circuit - which is typical of very small batteries like the 14400 and below), I suspect several ReX light batteries have been damaged as a result of some of the runtime tests users have been done.

There should be some documentation from the manufacturer stating if whether or not the ReX has low discharge protection or not. I think it is important information to have and warn users of the potential damage that may occur to the battery if the unit is discharged to complete dead. I do not believe the ReX has this circuit - but I could be wrong.

regulator said:

I have always suspected that there is no deep discharge protection for the ReX since others who have deeply discharged thier ReX's have had issues. I have never ran mine down very low and charge it even if it has had little use. It has had many charge cycles.

Their is a lot of information regarding rechargable batteries. Typically, it is better to charge them more often with low discharge than to let them discharge deeply and charge less often (except for cases with NiCads). You will get more cycles if you do not let the battery discharge very low than you would if you discharge the battery to almost dead.

Thanks for the info from Photon.

Click to expand...

Several gadgets that I own that came with LiIon batt's suggest that you fully charge a new cell and then run them through a few full-charge to full-discharge cycles to achieve full capacity. Is this wrong? Most of these have built-in protection (cameras, phones etc.) but what about other LiIon cells, is this even necessary with new cells and if it is how can you do this with a Rex without damage?

Are these directions just old material from the NiCad days? They specifically say LiIon on them but they might have change only that. Do new LiIon cells need to be conditioned at all?

The reason some electronics with Li-Ion cells suggest cycling isn't to form the cells, but to allow the circuitry to "learn" what is full and empty capacity. After a number of shallow discharge cycles, some software needs to "reset" and learn just how much energy is available for a deep discharge so it can more accurately judge the true capacity remaining.

This is only true for some electronics (especially in the old 90's laptop days), YMMV

Excellent point Marduke. The cycles is more for the electronics to learn the battery capacity. But it is still best not to deeply discharge the lithium ion batteries on a regular basis.