I bought it for 9 volt
I opened it and just skimmed the directions and read  in bold &#34;battery must be charged in pairs ( 9v cell can be charged individually)&#34;  I didn't take this to mean MUST be, it didn't say &#34;only&#34; and I put two in like any other type of battery and one blew up shortly there after.  Ruined a new rechargeable battery.  The other  9v was super hot, but is fine now.<br /><br />Since then I've used it correctly, and works well, but I don't like that the 9 v stands up vertically and you can't close the lid.  The fit isn't all that snug either.
Rating: 3 stars