answering my own question.. he he..

still for anyone else that wonders..

nickel cadmium = 1000 to 1500 charge discharge cyles.. very tolerant to abuse.. self discharge at 20% per month..

nickel metal hydride = 200 to 300 charge discharge cyles.. less tolerant to abuse.. self discharge at 30% per month..

lithium ion = 500 to 1000 charge discharge cycles.. but they start to die from the moment they are born even when not in use.. its possible for them to fail after two to three years just thru age.. self discharge 10% month.. best kept stored at 40% charge and cooler temps..

not entirely happy with what i have discovered about rechargeable lithium ions allowing for the price they cost.. but thats more down to the "proprietory" factor than the cost of the technology.. as time passes they should get cheaper and eventually take over from metal hydrides.. if u buy any spares check how long they have been on the shelf.. try to avoid buying old stock..

trog100