Tinman, I measured "just from memory" and with my Tanked up HF setup coupled to another Ferrite Yolk transformer, about an amp through a small globe rated for 12 v and 3 Watts, Ohms law says that would mean 0.25 amp max, I think. But does it ? The globe being considered a resistive load. But is it ? When I made that measurement it was AC at HF and I measured a phase difference between voltage and current, the calculations told me "again from memory" that the bulb was dissipating less than 3 Watts of power. Not sure if I have a video clip of that, maybe you remember it on OU.com. The bulb was lit pretty good "from memory"
I think the phase difference was real but likely off a bit and I think the current was close too, I think from memory the voltage was about 7 volts AC. I was convinced the bulb was passing current that did not contribute to the power dissipation. After all it was at about 400 kHz and the bulb has some uH inductance. I've got that setup all fitted up with high quality HF CSR's, and will get back to that later.
Anyway, this arrangement looks very simple and I should be able to replicate it close enough, I have two 7 amp hour SLA's with about 20 % or less capacity, and also one that is I think in better condition but is still quite sulfated.
I think I have a multitap E core transformer that steps down to 32 volts, or a higher power rated toroid with dual 12 volt outputs, I have a variac if there is something you want me to specifically try at some voltage, found a High power FWBR, I got plenty of caps ( I found the ammo box full of caps I lost, I'm stoked bout that)
I've got two different killawatt meters one has a much better resolution for Watts.
I only have one missing part that I should have but I cannot find the 21 Watt Auto globe. I had the 5 watt Tail and 21 watt Stop light in one globe type with wires already soldered on it, bit miffed. I'll nip into town in the morning and grab some.
Oh P.S. The globe is getting warm isn't it ? I can't see you mention it.