LSH-P Not as shock resistant as expected

This may make me unpopular around here but...

I have reason to believe the ARC-LS design may not be very shock resistant when paired with 2AA NiMH batteries. After three weeks of faithful service, my LSH-P died.

My LSH-P, fell from a table, bezel first, onto a linoleum floor. The LSH-P was attached to a 2AA pack (NiMH) and housed in a velcro nylon Maglite pouch.

The drop was lower than (my) waist level, about 80 cm (approx 30 inches). The light was not forced at the floor, just free fall.

Much to my dismay, the light would not turn on afterward.

It looks as if the added weight of the NiMH cells put excessive pressure on the back of the LED circuitry when the bezel hit the floor. The LED appears to have been forced forward, damaging the reflector slightly.

There's really nothing to absorb shock between the battery contacts and the batteries themselves. While this may not be a problem with lighter alkaline or lithium cells, NiMH cells are much denser.

I was surprised that the ARC LS had broken so easily, especially considering how much it cost. My Maglite has survived many falls like this, at worst requiring a quick bulb change.

I was hoping my LSH-P would last a little bit longer than three weeks.

I'm in the process of making a warrantee claim. However I'm not so certain that the next one will be any more durable.

Comments?

Looks like you already did the right thing - you contacted Arc about the problem. Part of the price you paid includes the benefit of excellent customer service. Peter is very receptive to problems with his products. I'm sure he'll straighten everything out.

I've been using ( and abusing ) Arc LS's for nearly 2 years and they are the most durable items I know of. I use the 2AA pack and the LS's have survived many a tumble.

My LSH - P survived a fall onto cement without any problem. Messed up the anodizing, but the light continued to work fine.

I have also dropped mine onto a brick walk - attached to a heavy set of keys (i.e. the weight was much greater than just the LSH) and it got a small nick in the HA finish but still works great. I've been very impressed with the durability of the ARC products - they've withstood many bumps including my little 19 mos old got a hold of my LSH once with the 2AA pack and dropped it numerous times on the hard wood floors. Never a hitch.

I can't say for sure but I think the reputation for durability means you can count on the next one working fine.

It is quite possible that the diameter of a 123 cell allows it to hit the retainer ring during an impact like this and the 2 nimh AAs would bear directly on the gold contact.

When I got my LSH-P I needed to use a Dremel to grind away a bit of silver "stuff" that had oozed out of the threads and prevented a SF123 from positive contact. (The supplied Duracell worked fine)

Other than that, mine gets used & abused and ALWAYS works!

Don't worry, Koji. Peter will make it good!

i dunno. it must've hit *just right*

Koji, did you try it out with the 123 pack, after fall?

Bill

In almost 2-years, I had my only ever "drop" of a light and it happened to be my EDC LSH-P. I was working outside on the XMAS lights and it slipped out of my hands. (Another reason for more agressive knurling Peter). Anyway, it landed right on the pavement. It has a small scratch, but that's about it. It still work, with no rattles.

During the course of my job my keys, with LSH-P attached, come out of my pocket a dozen times a day. Given this frequency and the awkwardness caused by a relatively heavy Squirt, also attached, my poor LSH-P takes a header about once a week. About a quarter of the time its onto cement or asphalt. It has its share of character marks, (the first was the hardest on me) but doesn't show a hint of malfunction.

What version battery pack were you using? Were you using the twisty 2AA or the clicky TSP-2AA pack? The reason i ask is because the twisty version relied on compression between the contacts of the battery, while the TSP-2AA uses a spring.

I would only guess that the spring in the TSP-2AA would act as a cushion in case of a fall, but i don't know how much protection that would offer. The older twisty version caused some problems just be simply over tightening the battery pack. Somtimes it would crush the cell or damage the contacts. In any case, i'm sorry to hear of your loss...i hope it will be resolved to your satisfaction, which i have no doubt it will. ARC's customer service is top notch.

It's possible the batteries themselves were damaged. I can't remember where I read it, but I once read a warning about imparting too much shock to NiMHs. I recall a AA of mine being damaged this way. I wound up throwing it out.

I would be very interested if anyone has any more info about shock and NiMHs.

The 2AA battery pack I was using was the push button type.

I tried replacing the tail with a 123 Lithium cell, as well as other AA rechargeable/primary batteries. Still would not work.

The NiMH cells that were in the flashlight during the fall still work well in other devices.

JackBlades is probably right about the retainer ring behind the LED circuitry. It's smaller than the diameter of 123 cells, and may protect the LED circuitry from a hard slap.

Also, the weight of a single lithium 123 cell is about 1/4 the weight of two AA cells. If you were to drop a LSH head first with a 123 lithium cell inside, the 123 cell wouldn't slap into the circuitry as hard as if you were using denser NiMH cells.

If most people use 123 cells, it might explain why my broken flashlight is an isolated case.

As for the shock resistance of NiMH batteries, I haven't heard of one battery type being more shock resistant than other types (I could be wrong). The most significant difference between battery types is the electrode materials / electrolyte (influences things like operating temperature and weight). For the most part, the physical layout is the same I think.

Check:

http://data.energizer.com/

Seems to have some useful information about their batteries (Lithium, Alkaline and NiMH…)

Look up the "application manuals" or a quick overview of the different battery types.