but there is no battery forum anyway
smart charger are a lot better for sure and are worth the extra money.
for example, i use li-ion rechargeable(no i am not kidding they are available) AA batteries for one of my flashlights.
those battery can start a fire pretty well.
but luckily, it has a protection circuit built into the battery to protect from over charging/dis-charging.
it is not those 1.7V ones btw, they are the 3.6V-4.2V kind of li-ions.
if there wasn't that circuit, it won't even use it, let alone charge it.
on those 9V rechargeables, in my opinion, they are quite useless.
why? because they don't really have much capacity.
compared to normal alkaline ones, they only have around a quarter of the alkaline's capacity.
so charging them frequently is a must.
i say, if jaben does want to sell 9V batteries, they should source for lithium 9V primary batteries.
not rechargeable, but give out the same voltage as a alkaline 9V, but has around double the capacity and has less mass/lighter the alkaline ones.
however, IIRC, they cost a lot more.