A noob question on electrical circuits and polarity

Joined
Jun 28, 2020
Messages
28
Context is I'm trying to rig up a relay for my TSDZ2 motor system to power a front light, and I realised how basic my understanding of electrical circuits is so please bear with me... :wink:

1. If you're connecting two batteries in series you connect the +ve of one cell to the -ve of the other.
2. but if you're connecting a consumer device (say an LED, or anything with a red and black wire) the convention is the other way around and that the +ve of the consumer device is connected to the +ve of the battery is that right?!
 
Charlie Whiskey said:
1. If you're connecting two batteries in series you connect the +ve of one cell to the -ve of the other.
Yes. That adds the voltage of the batteries.
2. but if you're connecting a consumer device (say an LED, or anything with a red and black wire) the convention is the other way around and that the +ve of the consumer device is connected to the +ve of the battery is that right?!
Yes. If you are connecting a load (or two batteries in parallel) then you match polarities.
 
Suppose you have two 12V car batteries with each having 60-Ah, and each can provide 100-Amps of temporary peak power.

If you connect the positive of one to the negative of the other, they are in series, and you now have a "pack" of 24V, which has 60-Ah of range, and can provide 100-Amps of peak power.

If you connect positive to positive, and negative to negative, they are in parallel, and you have a pack that provides 12V with 120-Ah or range, and it provides 200 Amps of temporary current.
 
Back
Top