My company just purchased one of the newer Hyster power trucks with the lithium ion batteries installed instead of the traditional lead-acid batteries.

Does anyone have any feeling or even better, actual experience with the reliability of these lithium-ion batteries versus the older lead-acid batteries?

I know that, in other applications, there have been incidents reported of battery fires with LiOH installed in various pieces of equipment and have noticed that this Hyster unit has a label affixed to it stating that "For optimal performance this unit should be charged when not in use." Seems like a recipe for battery overheating to me as well as a not-too-terribly good endorsement for charge-holding power of the LiOHs installed.

Thanks.