No if you mean the standard small rectangular 9vdc batteries, their internal resistance would not allow that much current to flow. You would need a different kind of battery. AA batteries of the right type (6 cells in series) could supply that current level for a while.
A good quality brand new 9V alkaline battery can supply 800mA for a few seconds but its voltage will quickly drop as it dies.
A cheap Chinese battery that has been on a boat for a year will not.
I have extrapolated curves from Energizer's site. Here is a load of 400mA:
A good quality brand new 9V alkaline battery can supply 800mA for a few seconds but its voltage will quickly drop as it dies.
A cheap Chinese battery that has been on a boat for a year will not.
I have extrapolated curves from Energizer's site. Here is a load of 400mA:
a FRESH 9V has about a 3Ω internal impeadence. That means that the most instantanious power that you can get out of a 9V is (9V/6Ω)²×3Ω, and only for a split second.
On the other hand if you look at the actual curves, they do not even bother showing more than a 100mA load. The fact of the matter is that you can not project an order of magnitude and it does not take a constant nor high current to charge a stun gun...a taser on the other hand...
Of course you cannot get a high current from this type of battery for any more than a few seconds. But the enquiry was for 800mA from a 9v battery.
If more information was supplied, a fuller answer could be provided.