Below mentioned things need to be checked;
Battery Charger (AKA) Denmo.
Loose connection of Battery terminals.
For overheating.
Check radiator (water leakage, blockage, hose pipe)
Check radiator fan. (Auto start, speed)
Thermostate Valve (maybe blocked) and if you couldn't replace it JUGAAR option is just remove it. Your car will work fine. Just you need to wait after starting to get it warm.
Waterbody (maybe blocked or rusty)
Cost of all above mentioned works shouldn't more than 2500. EXCLUDING SPARE PARTS