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I’ve been looking for this and couldn’t find the answer so far.

What’s the max current that those Li-Ion video camera protected battery packs, as the Sony NFP-550, NFP-970 can handle? I know for instance that the NFP-F550 has usually 2600mAh capacity and 7.4V, but has an internal protection circuit that handles short circuit, over and under voltages and also overcurrent.

Is there a limit in current they can supply, even if it discharges faster?

Thanks!

Edited for correction of decimal points!

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  • \$\begingroup\$ This is usually given as a C rating, where 1C is the current it would take to fully discharge the battery in one hour. So, for your 2.6 mAh battery (are you sure that's not 2600 mAh?), that would be 2.6 mA (if you meant 2600 mAh it would be 2600 mA). \$\endgroup\$
    – Hearth
    Oct 15, 2018 at 16:54
  • \$\begingroup\$ @Felthry in many other parts of the world, “.” Is used for digit grouping and “,” is used as the decimal separator. \$\endgroup\$
    – τεκ
    Oct 15, 2018 at 17:03
  • \$\begingroup\$ @τεκ That's confusing. I suppose it's just yet another case of the US doing things backwards. \$\endgroup\$
    – Hearth
    Oct 15, 2018 at 17:04
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    \$\begingroup\$ In that case there's an inconsistency, since the OP writes "7.4V" \$\endgroup\$
    – Nicholas Pipitone
    Oct 15, 2018 at 17:06
  • \$\begingroup\$ @NicholasPipitone Sorry. In my country is different and I mixed it. Now it's correct. (In my country is 7,4V) \$\endgroup\$
    – Rodrigo
    Oct 15, 2018 at 17:10

1 Answer 1

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The overcurrent protection obviously varies with the battery size and its purpose, and the actual threshold value should be defined in manufacturer's specifications.

If you can't find the actual battery specifications for your particular battery (I admit it is a challenge), you can try to determine that threshold by loading it up with variable resistor at your own risk.

You should consider that usual appliance batteries have a safe discharge rate of about 1C-2C, which, for a 2600 mAh battery would be 2.6A - 5.2A. So the manufacturer would likely set the current limit in accord with the type of cells they are using in their packs. The battery described in this SE EE question has the protection that tripped at about 3 A, causing some problems.

Keep in mind that there are "high-discharge" Li-Ion batteries designed for Radio-Controlled cars and flying apparatuses, they might have the discharge rate of up to 50C or more, or in hundreds of Amps (which is unlikely for the camcorder batteries, but anyway you've been warned).

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  • \$\begingroup\$ Thanks! I just managed to test it with some 10W resistors I had laying around (5 ohm equivalent with some resistors in parallel ) for a few seconds, and managed to draw 1.5A stable current, more than enough for my uses! \$\endgroup\$
    – Rodrigo
    Oct 15, 2018 at 20:50
  • \$\begingroup\$ To add: my NP-F330 can do 5.8V into 2 Ohm load (2.9 A), but turns off at 1 Ohm. To reset, it needs to be plugged into charger. \$\endgroup\$
    – Ale..chenski
    Oct 15, 2018 at 21:41

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