Filed under: FAQ by Jeff Servaas |
Is there such thing as a low self discharge 9V battery?
Well, no, not yet. But does it matter?
According to some people, the Maha 9.6V batteries are of a high enough quality, that they are in effect a low self discharge battery. Here’s a comment from a Maha 9.6V battery user in relation to using Maha 9V rechargeable batteries in smoke detectors:
“…I consider a smoke detector application to be low power such that
the self discharge characteristic of the battery will be the primary
driver as to length of use before recharging/replacement. With the maha
9.6v batteries in a various detectors, the run time is somewhere
between 6 and 12 months before the “replace battery” beeper kicks in -
all depending on the specific detector. The combo ionization/smoke
detectors or CO2 detectors draw more current than just ionization
detectors. Will those 9.6v batteries still supply sufficient current to
signal a _loud_ warning buzzer or beeping close to the end of their
useful charge? There was a CPF thread a while back that discussed that
aspect at some length. I tested a few of these specific Maha 9.6v
batteries under something I thought was close to end of charge – I had
to plug my ears to let the detectors sound off long enough to be
believable. No problem….
…While a 9V battery with the label of “low discharge” does not appear to
be available, in my experience the Maha 9.6v battery possesses
sufficiently adequate electrical/chemical characteristics to come close
enough to a “low self-discharge” battery for my usage.
BTW, you really need to purchase the Maha MH-C490F charger that charges
four 9.6v or 9V cells intelligently in a few hours, not all night as is
usual with 9V charging stations. and then leave the cells on trickle
charge after charge termination for longer than an hour. I credit that
charger for saving 4 existing older 9v batteries from the recycling
bin. It took a few charging cycles but the old 9V batteries were
sufficiently rejuvenated to become useful again.”