Old battery charger to new, possible?

[Far far north]

I've got nice 60 amp battery charger, but it's a dumb old one with no regulation of anything.
So I can't really use it with my new AGM batteries without risking to kill them.
But instead of buying a new fancy charger with all the modes and regulations, but with less amps for alot of money, I was wondering if it was possible to modify my old one?
Anyone got some info or links?

 

[Mike S]

Is the charger you have an on-board charger?

 

[Far far north]

No, it's mostly sitting in my garage.
But after some searching I can't find anymore usefull info.
Looks like it's not possible since I can't regulate the voltage.
Oh, well, time for an expensive new 10A charger...

 

[Far far north]

Found a product that turns any stupid old battery charger into a 3 stage microprocessor controlled charger.

Granite Digital® Save A Battery™ 12 Volt Battery Tester

Not badly priced either at around 40 bucks. Sure is alot cheaper than a new charger.