Add more amc7135’s. You may not reach the direct drive current but shouldn’t be to far behind.
You also have to remember that the battery can not stay at that voltage very long. So the amc7135 driver may fall out of regulation pretty quickly becoming direct drive. It would only regulate the current until the battery’s voltage (along with voltage sag and other parasitic losses) reached the vf of the led at a specific current. Using 6 amps as a example.
If you look at Djozz graph you can see at 6 amps the voltage needed to achieve that current would have to be some where in the 4v range after the other losses like voltage sag and other parasitic resistance. So if you added enough amc7135’s to give you 6 amps out to the led, the time it would stay at 6 amps would be pretty short considering the battery at 4.2v before any losses or voltage sag where factored in. Probably less than a minute, just a guess. Once battery voltage falls below 4v the driver becomes direct drive (Useless besides having modes). What ever the voltage the battery is maintaining (the blue line) will be what the led is seeing in current (at the bottom of the graph) in Djozz graph. If you look to the graph again you can see that once the battery voltage has fallen to about 3.5v (blue line) the led is only see about 2.5 amps (bottom numbers). Looking at a NCR18650PD graph looks like if you set the drive current with the correct amount of 7135’s to about 3 amps it would stay in regulation about half the run time, the other half direct drive at what ever the current it can push for the falling voltage. Hope I made some sense.
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Hope you are use a good heat sink with copper behind the led or she may not last long at 7.98 amps.
If you want to push a led at high currents and stay in regulation a buck driver is more suitable for the purpose.
Unfortunately, I don’t know of one that has a 17mm diameter putting out much over 3 amps.