**Q1:** I have a battery, say 15 AH and I have a load which consumes 1.5Amps; How does this used to see the capacity of a battery? If the battery is able to deliver 15 AH of capacity that means will it die/discharged in 10 seconds if I put a 1.5 Amps load on it since load is taking 1.5 Amps from battery every second or does it mean it will die/discharged in 10 hours? Is the rating on battery tells us the discharging rate in hours or seconds?
**Another question:** What will happen if I connect the AC terminals to battery? I know it won’t charge but will it explode or something like that? Is it dangerous for us/battery to do this thing? If I have a line wire from which both AC and DC are passing through and now I connect the battery with it, will it be able to filter its DC component from wire itself (and charge itself) or do I have to make a filter(rectifier) for it to separate DC 1st and then charge the battery?
**Q3:** What will happen if I use the neutral wire to carry both the DC + AC line? Should I use a thicker wire? Will it cause some different oscillations in the wire? Is it bad for the AC line?
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A 15Ah battery will provide 15 amps for an hour, 1 amp for 15 hours or 1.5 amps for 10 hours, in ideal circumstances.
AC is 110V in the US, higher in Europe / the UK. This will at the very least kill the battery, and it will probably overheat and maybe explode. You don’t want boiling battery acid in the face.
Don’t even think about it. It looks robust but this is to handle high current, not high voltage.
I can only speak to Q1 – You’re just misunderstanding Amps vs Amp-hours.
Amps is a *rate* of current flow. Amp-hours (which is Amps *times* hours) is an *amount of charge*. If a battery has a capacity of 15 AH, that means it has enough energy to provide 15 A for 1 hour before dying (or 1 A for 15h, or 3 A for 5h, or 5A for 3h, etc…). And that makes sense, because of course the more current you draw, the less time the battery can run for. It’s the product of amps x time that remains constant, so that’s what we use to define battery capacity. You can’t give a battery’s capacity in just time, because that depends how fast you’re draining it.
The true-ELI5: You’re trying to describe the volume of a bucket. Amps is how fast you are draining the bucket, the time is how long the bucket takes to drain:
“This bucket will take 15 minutes to drain a 1.5 liters/minute” is like saying “this battery has 15 AH of capacity”. Both are talking about the time it takes to empty the tank *at a specified rate*.
Q1: The rating on a battery, such as 15AH, indicates the total energy capacity it has. It means that the battery can deliver 1.5 amps for 10 hours before it gets depleted. So if you use a load that consumes 1.5 amps, the battery will last for 10 hours before it needs to be recharged. Conversely, if you use a higher load, the battery will discharge more quickly.
Q2: Connecting the AC terminals to a battery can be dangerous because it may cause a short circuit, which can lead to overheating, fire, or explosion. The AC voltage can vary depending on the source, so it may damage the battery or cause it to leak. Connecting a battery to a wire that carries both AC and DC may not charge the battery because the AC current will not be converted to DC, but it may cause electrical interference or noise.
Q3: It is not advisable to use the neutral wire to carry both DC and AC, as it may cause electrical problems. The neutral wire is designed to carry only AC current and it may not be able to handle the DC component. It could also cause interference or noise in the wire and affect other devices or appliances connected to the same circuit. It is recommended to use a separate wire for DC current or to use a transformer to convert the AC voltage to DC.
This is several layers of misunderstanding electricity in general and you should not attempt any of what you just asked.
Q1 was adequately answered by another commenter, I’m gonna focus on Q2 and Q3.
Q2: If you connect AC voltage to your battery leads, depending on battery type and internal wiring, you’re most likely to see the breakdown of whatever small internal circuitry they have, if applicable – reverse current protections most likely. After that, the circuit may either be broken down and the battery will become an open circuit element, it will either explode due to massively overloading the cells, or… if you somehow had a battery designed to resist such voltages and currents, nothing would happen. Batteries can’t charge on AC. This is because, as the name implies, AC waveforms are alternating. You have a positive and a negative cycle at whatever supply frequency your country uses. That means the battery will charge on the positive side of the wave, and discharge on the negative side of it. Since the cycles are precisely equal, your battery will never gain charge.
For the second part of the question, this is again massively misunderstanding electricity. A rectifier will not filter a DC component from AC, it will simply rectify the AC waveform into DC. So you wouldn’t need something like that. Leaving aside the incredibly bad idea of mixing AC supply with your own DC supply on the same wire, this is actually possible and done to a certain extent on closed systems only. To get the useful working DC voltage out of your live wire, all you have to do is use a different carry wire for the negative side of the DC(read: NOT THE AC NEUTRAL WIRE). Since the voltage received is just a difference in potential, ideally your DC device will never even notice there’s also AC on the wire. However, I must stress that this is a really really bad idea and any screw ups with grounding can be very dangerous, and will most certainly fry your DC device unless you have built in protections.
Q3: Every time you mention only one wire I cringe a bit. You can’t use a single wire for transmission. You have to use another for the return path. So if you wanted to put DC on your neutral wire, you still have another carrier wire you need to worry about. If you’re thinking of using the same live + neutral wire for the DC positive and negative connections, you will absolutely short your power source and it will absolutely die a gruesome death. Also your breaker will probably trip. And even if you use a separate carry wire for DC, if the neutral wire is grounded, which most are at least at the closest transformer, your DC power source will continually leak current to that ground, and if the ground is close enough that the parasitic resistance in the wire is too low, it will just short your DC source to ground. There’s just no winning, like why would you ever try this? Just do separate wiring for projects like this, lol.
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