When the voltage of your car's electrical system drops below a certain point, you will get lots of random errors and codes, flashing lights and other anomalies. I suspect that's what you were seeing with the seemingly random and un-repeatable errors.

OTOH, there's no way in the world you should have to replace a 2-month old battery, though of course anything CAN fail. The fact it's failed again indicates that there has to be a problem with the charging system (alternator or associated wiring). A quick check with a voltmeter would indicate if your alternator is working (or not). Any local mechanic worth his weight in rocks would be able to check this out for you easily enough (assuming you can get the battery charged and driven to the shop, of course). It's an easy DIY test, if you have a voltmeter (which can be bought for a few bucks from Harbor Freight, or even received as a freebie during one of their frequent coupon events). A good, charged battery should show between 12 and 12.5 volts, and a good alternator will bring that up to 13.5 to 14.0 volts.

 

 

It's the alternator or associated wiring. I'm going through the same issue currently. And the reman unit is not cooperating with the precise voltage required by the ECM so now I have a new unit coming. I hate doing work twice.