I'm in need of a new battery and was about to buy a AGM battery like the odyssey or the Pulse but the guy at the shop said they were no good for an everyday car battery. I was asking about the smaller 6kg or 9 kg ones. this was a specialised car battery place.

he also said they wont be enough as the auxiliary stuff runs from the battery and the amp hours are to low. i.e 17 or 28 compared to 70 of a lead acid. I thought everything was running off the alternator when the car was running. the battery was just there to start the car or power things when the car is not running.

now I tried researching amp hours and all that and I understand what they mean I think but still think as long as the battery is enough to start the car then the battery is good for the car?

I don't have a stereo or air conditioning so the only trouble I can see is if I leave my lights on accidentally.

is he correct? does anyone have either of these size batteries and they work ok for a NON daily driver?

imput greatly appreciated as I would like to save weight and discard lead acid type bats.

Hmmm!
The battery for a car should be rated in CCA, Cold Cranking Amps.
Ampere/Hours is no longer the ruler.
An automotive battery is NOT a deep cycle battery and vice versa, a deep cycle battery is NOT an automotive battery.
Deep cycle means running it flat and then recharging it fully many many times.
Once the engine is started, the storage battery, with the charging system operating correctly, receives a trickle charge from the alternator via the Voltage Regulator.
This is to ensure that the storage battery is fully charged to handle the next cranking task.
So, providing the cell/battery you choose can produce the CCA, it should be fine.
AT NO TIME should the battery be supplying current to the axillary load once the engine is running.
If it is, then the alternator/regulator are faulty.
That is why I like an Ammeter gauge.
If it doesn't show a slight + or CHARGE reading when the engine is running, problems I have!

_________________
Regards, Graeme
Just trying to help...
http://nissanman.shutterfly.com/
graemes@internode.on.net

thanks Graeme
just what I wanted to hear .

I also did some internet searching and found a couple forums where one guy had the small 6kg odyssey in his s15 for 5 years no drama as the sole battery and also someone else who had that 6kg one also in a R32!

at the very least i could put in a cut off switch on the negative line running through the cabin down near the base off the seat so If my car has power drain somewhere it wont be a problem if its parked for a week or so.