Electronic load for charging/testing small batteries

[RiRaRi]

I test a lot of older camera batteries. The biggest ones are 8V 2A Li-ion ones. But most of them are much smaller found in compact cameras. I need load which could charge and discharge/test capacity as fast as possible. I want decent device but accuracy is not very important to me. What to get? Thanks everyone for help.

[macboy]

I would use a charger for RC such as the ToolkitRC M6, or any of many similar devices. The M6 can charge and discharge with balancing for multi-cell batteries, at up to 10 A. High rate discharge is accomplished by using an external load resistor, or if you use a big lead-acid (car) battery as the power source, it will dump the energy back into that battery.  For a small compact camera battery, you would not need either type of external load, the charger can internally dump up to 10 W (that's nearly 3 A for a one-cell battery). This type of charger is very versatile, it can be set up for any type of lithium chemistry (Li-ion, LiPo, LiFe, etc.) or NiMH, NiCd, or Pb. They can cycle the battery several times, and track the capacity each time, so you can see if the battery is benefitting from cycling. Generally, it is safe to charge and discharge at "1C" rate, which means the 1 mA per 1 mAH capacity (so 600 mA charge or discharge current for a 600 mAH capacity battery). So a charge/discharge cycle will take about 2+ hours. You can't really rush it faster than that, not all batteries can be safely charged any faster.  Don't forget that after discharging, you need to also do a storage charge, to bring the cell back to about 60% or so, in order to safely store it for a long time (storage completely empty or full WILL damage a Lithium battery).

[Kean]

There are many options, but note that most general purpose electronic loads do not support charging unless it is specifically a battery capacity tester.

One battery capacity tester that I use is the ZKETECH EBC-A05+.  I've had a couple of these for about 8 years (originally bought on ebay), and they perform reasonably well for smaller battery packs.  They can be used on a wide range of batteries, unlike some other testers which are intended just for single 18650 cell testing.  The ZKE computer interface isn't great, but I rarely use that.

In terms of testing as fast as possible, you are limited by the max charge and discharge currents of the battery (and the tester obviously).  Note that testing at higher currents for faster tests will not be indicative of the battery in actual usage, but it can help with determining battery performance.  Do not exceed the safe charge/discharge specifications for the battery.  With an old battery, I'd always start of with a gentle charge/discharge/charge cycle.

Another really useful tool for checking older batteries is a battery impedance meter.  Check out the YR1035+.  This will allow you to measure the internal resistance, which will increase with age and affect usable battery capacity.

[RiRaRi]

I got some good answers here, thank you. But to sum it up: what is best device for my job? It does not have to be electronic load but best device to check capacity and possibly charge the battery? Thanks

[helius]

I'm fond of the charger-analyzers from SkyRC. The MC3000 is very flexible for all single-cell cylindrical batteries, and they have a range of units that charge and analyze multiple-cell packs, most named "B6" or variations thereon.

[nctnico]

I got some good answers here, thank you. But to sum it up: what is best device for my job? It does not have to be electronic load but best device to check capacity and possibly charge the battery? Thanks

I recommend not to try and charge discharge batteries as fast as possible but I'd try to stay below charging and discharging rates of 0.5C . This will cause least wear on the batteries.