The Heinrichs-Weikamp i-TTL strobe converter was not designed to work with slave units. Just hard wired strobes. And primarily a single strobe, though it has worked reliably when I have hard wired two, or even three Hartenberger strobes to it.
However, every strobe connected to a H-W device depends on some kind of battery that is used to power the H-W circuitry. In the case of the external H-W which they sold directly, this was a small Lithium polymer battery also contained in the H-W external converter. You have to open the external converter every two or three days to recharge. And opening is a nuisance. A separate charge cap would have made the converter much easier to use and less prone to flooding.
Sea & Sea has "repackaged" the H-W circuitry for their own converter and powered it with a throw away battery that lasts much longer. Several German companies also offer this kind of converter, a Mk III H-W powered by the same throw away battery as the S&S converter. I haven't used one yet, but have read that this battery lasts for many dives, not just a day or two. One advantage of the H-W converter is that it can be configured to work with a variety of strobes by resetting some of the small DIP switches on the circuit board, which is great if you change strobe types.
Ikelite uses their own Ikelite designed TTL converter. The Ikelite converter has the advantage of drawing its power from the NiMH battery pack in the strobe(s). This means that as long as the battery pack has enough power left to shoot the strobe, the converter works, too. No separate recharging. No throw away batteries. This is a BIG ADVANTAGE that simplifies the strobe game considerably. I can't say whether or how well the Ikelite converter would work with any slave device, but I can say that I have been impressed with how well the strobes have worked on the dives I've done with them.
Fred
