K10D battery - NP400 voltage dangerously high ?

Hi All
I bought a couple of Power Mart NP400 batteries from eBay as a back up but have not yet needed to try them. Out of interest I thought I'd test the voltage and it is 8.35 .... instead of 7.4. The Pentax comes in at 7.4.
I'm obviously now not going to use them but does anyone if that the extra volt would actually damage the camera ?
Out of interest, has anyone else got some NP400s they could measure ?
Cheers

Ny NP400 comes out at 7.9v - the Pentax to 7.7v. Both are labeled 7.4.

There are a number of LiIon technologies - but all produce cells of between 3.6 and 4v. The camera bateries are obviously dual cell - but even so you should not be able to get 8.35v out of one.

For more on LiIon batteries see
http://en.wikipedia.org/wiki/Lithium_ion_battery

I have 2 of them and been using them for a while without any noticable problems. But i will test the voltage on them and get back too you.


Have you tested the Pentax original to see what its putting out :

I have tested cordless drills in the past and found the voltage is always higher when fully charged and then drops a few volts as the battery depletes (food for thought)

Thanks for the reply.

I just looked again and it's definitely 8.35 .... maybe it's because I left it in the Pentax charger for several weeks plugged in. However, the LED wasn't on and a power meter indicated the unit wasn't drawing any power.
I'll probably still chuck it to be on the safe side.
The Pentax was 7.4 spot on.

Actually, checking battery voltage without a load on the batteries will often lead to erratic readings. You should check the manufacturer' recommended procedure to check the batteries, i.e. a load is necessary or not.

Well i checked the voltages of my 3 batteries, But not under load as pentaxian450 suggests. And i came up with 3 different results.
The Pentax original was fully charged and was at 7.7
The first of my NP 400s was the one in the grip and currently being used so its not fully charged and it was 6.9
The second of my NP 400s was fully charged and it was 8.0
I wasn't sure what to make of it, so i asked the electrical engineer at work and he re-tested them and said it was normal to get these types of readings on batteries and they would be fine to use

Ah ok, I'll use them then if they're all like that. Thanks for the confirmations

I have just carried out a test and the results for my three batteries (all fully charged) are :-

Original Pentax battery - 8.3
NP-400 equivalent - 8.3v
NP-400 equivalent - 8.3v

I also tested the Pentax battery in a partially discharged state and it was 8.0v.

With marine electronics 12volt items theoretically run at 12.0v but in reality they can 'receive' anything from 11.0v (a heavily discharged battery or batteries) to over 14.0v (when batteries are being charged).