I've just taken 3 x AAA batteries out of a torch as they are down to
about 1v each and not enough to shine nicely.
But in series that's 3v. So a box with suitable connectors for AAA
and AA batteries connected in series/parallel surely could extend the
useful life of alkaline batteries. What's the downside?
1. Internal resistance will be high, so as soon as you take a load, the
voltage will drop further.
2. They may be more likely to leak. (Zinc/carbon ones certainly may, as
the zinc casing is dissolved during discharge.)
3. You won't be able to fit the larger number of cells in the torch,
unless they are hanging out the back with string and wires to
4. People will think you are inordinately tight.
Why don't you put them in the oven, or connect a charger (but not too
much current as alkalines will explode).
That has to increase current and hence reduce voltage further. No the only
way to extend their lives is a charger that is used very few sessions on
use. However this could, in the long run cost more than binning and buying
or biting the bullet and getting good rechargeable in the first place. Note
that led torches tend to be just as bright on rechargeable as alkaline as
they have a circuit to control their current to stop them overheating.
This newsgroup posting comes to you directly from...
Some people recharge alkaline cells but even with a special low
current charger it's not for the faint hearted.
Anyway the additional charge is only modest and needs applying well
before the cell is depleted. I suspect 1v is already too low.
Completely off-topic but watching the video I noted the bright yellow
multi-meter just like I had until last week (see the car battery
I wanted to check the parasitic leakage from the battery when at rest
and was all set up to do this when I realised that I had a problem to
make the connection without losing battery power to the car radio.
I had checked using the voltmeter setting that I had a good earth
point on the car (+ve to earth) and so connected the meter across -ve
to that earth point with the intention of measuring current, and set
about disconnecting the battery to earth at the earth point. In the
process of doing this I knocked the meter connections so before I
removed the earthing bolt I thought I'd better check I still had a
good connection and clamped back to the +ve of the battery.
Woooshhh - my wife said "it's smoking". Yes, forgot to set back to
volts and put the wire in the other socket on the meter. So just ran
open circuit +ve to earth via the meter.
Perhaps I'd best stay away from electrics.
On 06/05/2017 16:56, email@example.com wrote:
that one range that's affected.
I thought all multimeters whistle if you switch away from the high amp
range while plugged into the high amp socket. And they all have a fuse,
surely, in the amps circuit?
A few weeks ago, I had a similar current drain investigation to do on a
car, and setup the meter and wiring correctly on the 20A range, using
the 20A socket, circuit in series, not worried about the radio, ignition
off (obviously) etc....
Then a spark from made connections and the crappy meter leads got quite
hot. Meter reading was dropping to less than an amp, but losing voltage
in the meter leads due to rising resistance from heat probably
invalidates the readings if anything.
So my immediate mistake was using Maplin meter leads of insufficient
construction to carry possible currents I might be measuring, unexpected
ones as well as expected.
Seems something electro-mechanical in this 2003 VW Polo, takes an
initial gulp of current on an initial battery connection. I thought I
heard a motor, but it's neither ventilation or the radiator. Auto
priming fuel pump? the drivers door was open.
However, that investigation can wait for another day. I maybe also
should stay away from car electrics and glitching ECUs with my
intermittent battery connections.
Really need a cheap (<£50) clamp meter that does DC, if anyone has a
Best way is to connect the DVM before removing the terminal from the
battery. Let the car electric go to sleep, then remove the terminal. An
easier way is to buy one of those battery disconnect devices that fits
between terminal and lead, with a knob you unscrew to disconnect it.
*Snowmen fall from Heaven unassembled*
Dave Plowman firstname.lastname@example.org London SW
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