On Tue, 21 May 2019 02:01:46 -0700 (PDT), wrote:

On Tuesday, 21 May 2019 02:57:08 UTC+1, Jeff Liebermann wrote:
On Mon, 20 May 2019 15:18:29 -0700 (PDT),
wrote:

I purchased a 3 pack of the model 350 at Costco. Everyone one of
them has this issue. 3 months is about right. Put new batteries
in all of them and a few months later they all are virtually
drained of battery life.
Matt C

...
cork instead of a wine bottle cork. However, I haven't seen anything
for doing it with 4 alkaline cells. That's probably a waste of time,
so I suggest you recycle the flashlight and buy something that runs on
a LiIon cell and not on alkaline cells.

or use NiMH
NT

Yep, that will work better than alkaline. 800ma-hr for NiMH instead
of 750ma-hr for alkaline. The actual difference will be larger
because NiMH tolerates high current loads better than alkaline.

I'm partial to LSD (low self discharge) NiMH cells. About $2.50/cell
from China:
https://www.ebay.com/itm/400827732093
or $4.00/cell from USA vendor:
https://www.ebay.com/itm/153458804452
Four cells per flashlight would cost $10 to $16 per flashlight. For
that price, I could buy an equivalent LiIon flashlight, and still have
some money left over for a crude LiIon charger. Most of these:
http://www.learnbydestroying.com/jeffl/crud/LiIon%20Flashlights.jpg
were $5 to $10/ea plus charger.

I forgot to mumble something about the leakage current. Because the
on-off switch is usually in series with the battery, the "off" leakage
current should be zero. Yet, the Duracell Durabeam Ultra 350
flashlights seem to be leaking some current. Therefore, my guess(tm)
is that the flashlight is wired in a somewhat different manner. Since
the purpose of this flashlight is to sell more AAA batteries, I
wouldn't put it past Duracell to put something across the switch or
use a different wiring configuration to produce some leakage current.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558