What make are they? Top-end Duracells cost less than that :s
Only have your word they last 4x longer...What would you class as 'normal batteries'? Maybe a pic would help?
Sorry for the scrutiny but you see what I mean
-Will
9-Volt
Our lithium 9-volt battery is a consumer-replaceable battery that lasts up to 5 times longer than ordinary alkaline 9V batteries and 10 times longer than carbon-zinc batteries. It has the highest energy density, flattest discharge voltage curve, longest shelf life, widest operating temperature range, and lightest weight of any comparable 9-volt battery.
A 10-year service life makes our 9-volt battery the choice for major smoke alarm manufacturers for their premium lines of 10-year ionization-type smoke alarms.
And as a consumer-replaceable battery, consumers can instantly upgrade any application requiring a 9-volt battery.
Product Voltage Capacity
U9VL-FP 5.4 to 9.9 V 1.2 Ah @ 9 mA
to 5.4 V @ 23° C
U9VL-J 5.4 to 9.9 V 1.2 Ah @ 9 mA
to 5.4 V @ 23° C
if you buy them off a uk company it is £5.40 plus vat per each batterty and drops to £4.81 per batterty if you buy over 100