Using 24V and 12V from batteries in series

I am in need of 24V and 12V for a RC Lawnmower project. What are the possible issues/concerns with using both 24V and 12V from same two batteries?

The 24V load will be in excess of 40 Amps but the 12V load will be less than 2 Amps. The batteries are 12V Deep Cycle batteries (75 Ah).

What makes you think there will be a problem?

A quick google search on subject made me hesitant. I am just checking to see if anyone has experience with this.

Since the load on my 12 V line is much less than the load on the 24 V line I feel that I think that I should be fine, however I am not certain as one battery will technically discharge faster than the other. This may not even be an issue?

Has anyone done something similar?

If you are worried about one battery getting drained faster you could use a DC-to-DC Converter to get 12V (or whatever voltage you actually need) from the 24V rail.

mech_eng: I am in need of 24V and 12V for a RC Lawnmower project. What are the possible issues/concerns with using both 24V and 12V from same two batteries?

The 24V load will be in excess of 40 Amps but the 12V load will be less than 2 Amps. The batteries are 12V Deep Cycle batteries (75 Ah).

The 12v load is more or less just going along for the ride. This is rather like having a 12v radio in a 24v truck. If you feel uncomfortable about the windows of use, you could switch that load to the other battery occasionally.

You can tap from the middle of a battery string. It tends to be frowned upon as a technique especially with a large(ish) current draw, but it does work.


Rob