Two Batteries in series - Page 1
Forum section: electronics / beginners

author: GMG
author_rank: Newbie
timestamp: February 06, 2022, 07:36:33 pm
content: Hi, can someone explain me how two batteries in series can work ?A single battery has + and minus that are isolated, otherwise electrons from - will discharges on +, so how is possible that two 1.5V batteries in series will be 3.0V if the central part are isolated from external + and - ? Why central part - doesn't discharge on permanent connected + ?I don't know If I have explained well what I mean

author: ledtester
author_rank: Super Contributor
timestamp: February 06, 2022, 07:44:42 pm
content: Quote from: GMG on February 06, 2022, 07:36:33 pmIn order to current to flow there must be a circuit.That is, an electron starting at the negative end of a battery must find a conduction path to the positive end of thesamebattery. The battery then completes the circuit.The negative of one battery touching the positive of another battery isn't a complete circuit by itself.QuoteFor simple circuits you can think of batteries as being pumps -- here is an explanation of that analogy:http://hyperphysics.phy-astr.gsu.edu/hbase/electric/watcir.htmlThe + and - ends of a battery are "isolated" because a pump only pumps water from one end to another.Two pumps in series will produce a higher pressure output than either of them alone.However, in order for any current to flow there must be a circuit. A break in a circuit is like a pipe with an end cap or a closed faucet -- there is pressure behind it but no flow.

author: Gyro
author_rank: Super Contributor
timestamp: February 06, 2022, 07:53:37 pm
content: This question seems strangely at odds with your previous thread, particularly your final post referencing opamps etc. Is your account ok?https://www.eevblog.com/forum/testgear/purchase-advice-rigol-mso5074/

author: GMG
author_rank: Newbie
timestamp: February 06, 2022, 08:05:37 pm
content: Yes, I have basic notions of electronics, I know how a circuit work and I know how to analyze that but I have a very little know how about batteries, I don't know how this question will be in contrast with the oscilloscope one, I'm a programmer not an electronic, so not all electronics is well clear for me.

author: ledtester
author_rank: Super Contributor
timestamp: February 06, 2022, 08:11:31 pm
content: I should add that the "isolation" between the + and - ends of a battery is not absolute -- it can be overcome by putting a larger voltage source in parallel with it. This is exactly how you charge a rechargeable battery, for instance.

author: TimFox
author_rank: Super Contributor
timestamp: February 06, 2022, 08:12:19 pm
content: A simple explanation is that if you complete the circuit with a reasonable resistor from the + terminal to the - terminal, current flows from the + to the - through the resistor, discharging the battery over time.

author: BeBuLamar
author_rank: Super Contributor
timestamp: February 06, 2022, 11:43:49 pm
content: Quote from: Gyro on February 06, 2022, 07:53:37 pmOr he is trying to pull our legs. What if the answer that they just work. You put 2 1.5V batteries in series and use a meter to measure you will get about 3V.