Werker SLA batteries? (... better than PowerSonic?)

Not all Batteries are the same as well as not all chargers are the same.
The chargers have different charging tables. Some of the higher end smart
chargers detect the type of battery it is and can charge appropriately but
there is not one charger that can do it all. Sorry. Your life expectancy of
a battery will go up drastically when you use a compatible charger with
your new battery. Talking to battery experts is very helpful here. A pefect
example is the pardigm shift to Litho Batteries for capacity reasons from
NiMh.
If you have an old charger, they will not charge Litho batteries well.
Dependant on the charger you can get a variable outcome. I have seen
everything from Litho batteries catching fire on an airplane to just
charging a battery to 50% capacity. If you are going to update your
batteries to the greatest capacity, spend the money and buy a compatible
charger. Regards, Doug

P.S. a Litho battery fire is extremely difficult to contain. Never leave
these batteries charging unattended. Don't believe me, goggle search it!