multimeter results

glicster

i got a multimeter 2day and put it across my batterys(i thought one was breaking down) and each reading was 1v more than the rating of the batterys. my 9.6 showed 10.4 and the 8.4s were 9.2/3. when i put it on a new AA batt. i got 1.4v
ive never used a multimeter b4 and this is only a cheap one i picked up so just wondering are the readings justifiable considering the AA, i presume showed up right,or is there dark forces at play here?
i had set it at the right range

Leftyflip

That's what all batteries should read, when they're dead, they'll read 8.4 or 9.6

glicster

cheers lefty,so as a matter of interest what should a fully charged 9.6 show as.

oops,re read your answer and i think youve already answered that,ta

elDiablo79

fully charged 9.6v nimh sud read nearly 12v

NakedDex

No it shouldn't. An overcharged one might.

Each cell has a nominal voltage of 1.2V in a NiCd or NiMH pack. A charged cell should read approximately .2V higher than nominal, and a depleted cell should read .2V lower.
A "dead" cell would read far lower, closer to 1V below nominal. These are cells that still provide connectivity within the battery, but don't actually contribute to the overall output voltage (which is also the most common reason for battery failures).

Going by this, a 9.6V pack should read 11.2V at maximum charge, and 8V when depleted. An 8.4V pack should read 9.8V at maximum charge, and 7V when depleted.
However, in normal operation, it's highly unlikely that you'll actually deplete a battery fully. On most 1J AEG's (discounting short stroke and "long-box" systems, as well as some high torque motors), your motor will require a minimum of .6-.8V below nominal to overcome the compression of the spring acting against it. This point should be taken as your effective depletion reading.

Again, going with the above, your 9.6V battery becomes ineffective at between 8.8V and 9V, and your 8.4V battery becomes ineffective at between 7.4V and 7.6V.

The numbers run differently for LiPo 3.7V) and consumer alkaline (1.5V) cells. LiPo often varies with discharge rating and manufacturer, while consumer alkaline cells (your bog standard AA, etc) are between .2V and .4V, depending on manufacturer.
Physical size of dry chemical cells will determine their maximum capacity.

glicster

nice bit of info dex cheers