I recently bought a small trickle/float charger that can charge batteries from 15AH to 150AH (at like 13.5vdc).
Would it be safe to use it to charge my 12v 4.5AH SLA batteries with it? If i put them in parallel, or is that not a good idea?
I know one battery is in good condition, but i am not sure sure about the other one... i plan on buying 2 brand new SLA batteries soon (for random projects)
I question that it will be suitable unless you monitor the charge voltage.
If it never exceeds 13.8V it will work fine, but if it exceeds 13.8 it must be removed when the charge current = the capacity of the battery/100.
For a 7AH battery this is 0.07A. If you don't remove it the battery could become overcharged.