Can I connect a standard 12V battery to an AGM 12V battery to create a 12/24 volt connection

[Blue Streak]

Are these two types of batteries compatible in this circuit? Will this configuration create problems?

[MN Fisher]

If you're gonna connect two batteries - either in series (voltages add) or parallel (AHs add) - always use two identical batteries. Same brand, model, and even age. Never connect two different batteries together.

[flyfisher]

Rule of thumb is when creating 24V using two 12V  you want the same type and same age of battery to prevent potential issues.  I have always followed this rule of thumb and had no issues.  Battery problems can vary from an inconvenience of no power when needed to creating a fire.

[GaryH]

2 hours ago, Blue Streak said:

Will this configuration create problems?

Simple answer YES. As was mentioned already when connecting multiple batteries always use the same exact battery of the same age if you’re looking for trouble free performance. And always use the proper charger.

[Blue Streak]

Thank you all for your help, I will follow your advice