shelf life of ARC4+

I got a second ARC4+ last week and wondered if long periods of non usage will damage the light, especially the electronics?

id say know long as battery dont leak

Shelf life is probably longer than your lifetime. As raggie pointed out, don't store it with a cell inside.

thanks, I was just worried about little capacitors etc in the electronics that might need a little juice every now and then. Don't think it will lie around for long anyway.

There may eventually be an issue with the floating charges in the eeprom memory. They may eventually forget their contents. I don't think operating the flashlight will help with that. But it should be a number of years before anything happens. I believe some computers and electronics from the 1980's are starting to fail because of this.

Electrolytic capacitors typically start to degrade after many years of disuse. But as I said, MANY years will have to go by before their capacitance values (in µF or microfarads) would start to noticeably decrease.

I dont store any of my lights with cells in them. That 4+ will probably outlive you if its put away in a safe, not too humid place, And by not too humid i mean dont stick the think in the fdridge or anything, lol

Humm, after taking apart the ARC4 to parade rest, exposing all it's electronics, I'd be highly concerned with simple thermal cycling from day to night temperatures, long term. Also concerned with flux residues left over from ARC plant assembly. The board builders did an okay job of cleaning the inside electronics on the boards.

The ARC4 does not contain any electrolytic capacitors. Another concern is code corruption by particles that are found in nature, upsetting the cells that contain the 1's and 0's. It is much worse at higher altitudes and even more a concern for aircraft. As electronics shrink (the silicon die inside), to more recent and ever decreasing sizes, and especially with multi-level storage technologies, the likelyhood of individual cell upset evens rises significantly, to the point that even FPGA's running "code" have been a serious topic of discussion amongst EE's in Aviation, such that it has spilled into the mainstream EE Magazines a few times.

I had thought that memory corruption from particle hits was mostly of concern for DRAM, and is reasonably well handled by ECC. I guess it must also be an issue for FPGA's. I wonder if anyone has tried to apply ECC to the interconnect switching in FPGA's. Putting it in the logic blocks doesn't sound too costly.

The issue with eeprom that I mentioned was just plain gradual charge leakage over time, not particle hits. It would also apply to flash rom. I don't have any numbers about this though. I'm just a software guy.

[ QUOTE ]
paulr said:
There may eventually be an issue with the floating charges in the eeprom memory. They may eventually forget their contents. I don't think operating the flashlight will help with that. But it should be a number of years before anything happens. I believe some computers and electronics from the 1980's are starting to fail because of this.

[/ QUOTE ] Does that mean eventually all ARC4's will be affected by this? Regardless of usage?
Thanks for all the answers so far.

I don't know. All such memory may be vulnerable. I do know that my late-80's HP calculator recently stopped working for no reason that I can discern. It's a matter of concern for the retrocomputing crowd (people who like to restore and operate vintage computers, sort of like vintage car buffs).

Is the best we can do about it is store it in a cool, dry and dark place? With moisture and oxygen absorber?

The best thing to do with it is carry it with you and use it every day, like its maker intended.

Not everyone wants to EDC every piece of Arc that he have. Even so, a EDC piece may eventually retire to collection status.

I will take a wild guess that the best way to preserve the eeprom contents is to store the light in a freezer. But I'll defer to experts on that question. I've already told you three times as much as I know. /ubbthreads/images/graemlins/wink.gif

[ QUOTE ]
NewBie said:
Another concern is code corruption by particles that are found in nature, upsetting the cells that contain the 1's and 0's. It is much worse at higher altitudes and even more a concern for aircraft. As electronics shrink (the silicon die inside), to more recent and ever decreasing sizes, and especially with multi-level storage technologies, the likelyhood of individual cell upset evens rises significantly, to the point that even FPGA's running "code" have been a serious topic of discussion amongst EE's in Aviation, such that it has spilled into the mainstream EE Magazines a few times.

[/ QUOTE ]

This so-called "single event upset" (SEU for short) plagues mainly static memory cells (FPGA's from the big two use SRAM based cells) and not flash memory if memory serves me right, no pun intended. As paulr stated, this includes DRAM. SEU's are predominantly seen in space applications though higher altitude does come into play. Since the code set is in flash memory, I wouldn't worry about SEU.

As far as long term storage, why not use the Arc as Peter intended it to be? It's a tool, nothing else. You guys paid close to $200 for it, why not get your money's worth out of it. It's like buying Snap-On tools and then stashing it in the cabinet, never to be used because the mechanic is afraid of marring it or scratching it.

CM

[ QUOTE ]
paulr said:
I had thought that memory corruption from particle hits was mostly of concern for DRAM, and is reasonably well handled by ECC. I guess it must also be an issue for FPGA's. I wonder if anyone has tried to apply ECC to the interconnect switching in FPGA's. Putting it in the logic blocks doesn't sound too costly.


[/ QUOTE ]

Putting ECC in logic blocks would overly complicate things for a "mostly" non-problem. Cost would skyrocket and performance would grind to a halt. The way this is attacked in space applications is to use triple redundant majority voting logic with partial reconfiguration on the section that has been voted as the one that lost its brains. Much simpler than ECC'ing the interconnects, something which is not required for 99.99999% of all applications.

Forever...

If i remember correctly, the Arc4 refreshes the flashrom during use.

That is correct. It should last quite a long time.

Peter