How do you find out how many amps your battery is putting out?

Answer 1

Amperage is a rate of electrical flow. In a battery-powered electrical circuit, as in almost any circuit, the current flow is a factor of the load, not the supply. For example, a battery powering 2 bulbs in parallel will supply a flow double that with a load of one bulb. The measured amperes from the battery would be double. While any battery has a maximum discharge rate, this is rarely reached when used as designed. When a battery-powered device is operating with the specified battery, it will draw power from the battery at just the rate (amperage) it needs. Batteries are, however, rated as to how long they will produce a current of a stated amperage. This rating reflects the total capacity of the battery. The units of this rating are commonly milliamp-hours, or mAh. For example, a particular rechargeable cordless-phone battery is rated at 800 mAh. This means the battery can store enough energy to release 800 mA per hour for 1 hour; or it could release 1 mA per hour for 800 hours; etc. (Not every battery is tagged with this information, but the manufacturer can provide it.) Therefore, selecting a battery is a matter of choosing one that:

- is rated at exactly the voltage the device specifies

- has the best mAh rating for the price

- fits the device properly and has the matching connections needed.

Then just be certain to install the battery in the proper direction, matching the stated polarity expected. (Match the "+" end of the battery to the "+" contact, and "-" to "-".) Caution: We have to consider maximum source amperage when powering equipment from line power sources, such as a wall plug or a power transformer plugged in to the wall. In this case, be certain the total specified power draw (in amperes or milliamperes) does not exceed the maximum amperage rating of the source. For example, your breaker box will likely trip if the total power draw from a room's wall plugs exceeds 15 A. And an overloaded power adapter (wall transformer) will overheat or perhaps burn if powering a device that demands more power (milliamps or amps) than it is rated to provide.

Answer 2

The amps being delivered by a battery depends on what it's connected to and what

job it's doing. When there's nothing connected to it, it's supplying zero amps.

To measure the amps with an ordinary multimeter, the amps must flow through the

meter. That means you have to disconnect one wire from the battery and temporarily

wire the meter into the 'gap', so that all the current flows through it.

Answer 3

-- If you know the resistance of the circuit connected to the battery, or if you can

measure it with your ohmmeter, then the battery current is

(battery voltage)/(circuit resistance).-- If you don't know or can't measure the circuit resistance, then the only way to

determine the battery current is to measure it with your [milli]ammeter.

Disconnect one of the wires from the battery, and insert the current meter right there,

in series with the battery connection.