1988 Reliant Issue

I'm having a problem with a Reliant, It's a family car with only 1 previous owner it has only 60k miles new tires etc. It runs great for it's age but it stales once in a while, it seems to do it most in heavy traffic, but it always starts up fine. Sometimes when it stalls it says "Powerloss" I searched other forums and I did the test and got code 47 which says Low Battery Voltage or Low Power to Alternator. My family member told me when I got it that down the road it might need belts replaced, my dad being car savvy check out the car and said they looked fine and wasn't sure what made it stall, I told him about the Battery error and he said it didn't have anything to do with the staling that it might have something to do with idling settings. Any suggestions? I don't have a ton of money to be ripped off by a mechanic but if I can pinpoint the problem and buy the part my dad could replace it. Thanks in advance.

Check your ground wire, from battery to the block!!!! This has happened to me on a Ranger.

Is it over heating? if so could be thermostat.

check air filter, fuel filter, plugs, although these things would probably make it hard to start.

Thanks for repling, nope it's not overheating and it starts fine. I will check the ground to the block see if that helps, thanks.

Ok, the ground will sometimes become corroded, and while it will usually restart, it will lose connectivity while driving. I would take it off and clean it up.