IDX batteries on A/B charger - fails to charge

[Phil Rhodes]

Hi folks

I have some IDX CUE-D95 batteries. I have an Anton Bauer LP2 charger. When I attach a flat IDX to the LP2, it flashes green and red for a few seconds, as you'd expect, goes red for a minute or two, then flips back to green, indicating charged. Has anyone seen this?

Same charger charges Anton Bauer Cine 90, Titon 150, and Core SWX Hypercore 75 quite happily.

P

[Frank Hegyi]

I know core swx promotes the fact that they're compatible with anton bauer chargers. I always thought they were all interchangeable. Maybe not?

[Robin R Probyn]

.. all their literature says only use with iDX charger .. and the warranty doesn't cover 3rd party chargers ..  very good batteries ,Ive used them for many years .. and always had iDX chargers .. and presumed their insistence of iDX chargers was just to make to buy them.. but maybe thats not the only reason and they really don't work well on other chargers ..?

[Dom Jaeger]

Modern batteries are full of electronics that allow for communication with chargers, but there's no guarantee one manufacturer's internal battery electronics will necessarily work seamlessly with another one's charger circuit, even if they share the same mount, unless they specifically advertise the fact.

 

[Phil Rhodes]

Thanks, folks. I shall bend IDX and A/B's ears about it at the BSC show on Saturday.

If it were something to do with electronics I'd expect it to not even attempt to charge, and I have managed to get it to charge one of the IDX packs, once. I wouldn't expect it to attempt to charge then go wrong. For general information, there's not necessarily much communication going on between most chargers and most batteries, most of the time. The electronics in a lithium-ion battery (any lithium-ion battery, from camera to laptop to cordless drill) is generally designed to balance the cells, prevent over- and undervoltage and overcurrent situations, and provide the fuel gauge. None of that requires communications with the charger. You can charge most camera batteries with inexpensive programmable hobby chargers quite effectively, and there's no comms going on there. You just have to tell it roughly what the capacity of the battery is, or leave it set to a relatively low current and accept it'll take longer than necessary to charge. Pro chargers usually try to detect the capacity automatically by assessing the impedance of the cells and I wonder if that's why it's failing; perhaps IDX are using unusual cells.

Features that require communications with the charger might involve the charger learning the capacity of certain identifiable batteries, tracking that capacity as it degrades with use, and charging appropriately. All that tends to require is a simple serial number often sent over an I2C bus. Laptop people do this to prevent counterfeiting, but from what I've seen, most camera battery suppliers are not attempting to screw people over like this. From the underlying engineering, I suspect this is Anton Bauer's automated charge program selection screwing up for some reason. Charging lithium ion batteries is actually not that complicated; it tends to go like this:

- Increase voltage until c÷x current flows, where c is the capacity of the pack in ampere-hours and x is some sort of safety factor depending how hard you want to push. x is often 2, so the battery will theoretically charge in 2 hours plus some inefficiency factor.

- When voltage reaches 4.2V/cell, or 16.8V for a 4-series-cell pack like most camera batteries, varying very slightly depending on application and cell type, wait until the current flowing reaches some arbitrarily low level. Some critical applications, such as aviation, charge to 4V/cell for safety. Optionally, sit in this very low current state for a while to top the battery off.

- You're done.

I now realise it won't charge one of the Titon 150s too, which is an alarmingly expensive discovery. Just sits there flashing red and green and never starts to charge. Gah.

Anyone got an IDX charger they want to sell?

[Robin R Probyn]

I just had the opposite .. charging nano 2 FXLION mini V mounts on an iDX charger .. praying it would work.. and seems to have done so..  phew !..  but iDX do make a big deal of only using their chargers for their batts.. marketing I guess.. but it also voids the warranty ..!! according to the fine print .. 

[Phil Rhodes]

I bought these IDX used, though very new, so I'm not sure I'd get the warranty anyway. In the end I bought a Hawk Woods 2X2 and it appears to charge everything fine. I really need another one so I can charge four at once but in general all is well.

Hawk Woods were very helpful and nodded knowledgeably when I described the problem, describing some technical measures they'd taken to ensure IDX compatibility. So, hats off to Jason and all at the company.