It is. But that will probably not be the reason.
Originally Posted by Ira Rush
Lithium batteries are a more recent invention than the 45 CL 4.
(P.S. see that tkamiya made the same point.)
But anyway, i was making a point about NiCads. Not Lithium batteries.
The problem using NiCads and the older 45 CT Series Metz units was something about the 'ready' light and when that would light. The CL series got a different circuit including a different ready light.
The bigger problem however was that NiCads then held half of the capacity of normal Alkalines, less than that even when the NiCads were getting old. The flash would recharge slower too.
But only such inconveniences. Never a danger to the unit itself.