Halogen Heater as Load Tester??
Can halogen heaters designed for use with 220-240VAC be used as a load to test DC batteries?
Does it need a minimum voltage to function, or is it "dimmable" like incandescent lights?
Here is a page with a bunch of similar products: http://www.amazon.co.uk/b?ie=UTF8&node=3147691
I hope it is possible to use one of them for testing 125V DC and 150V DC batteries; and to use two of them in series to test 300V DC batteries.
The halogen heaters I have have three elements with 400W each, so it might allow a degree of "fine-tuning" the current draw.
This is of course quite dangerous - fire and electrocution are very real risks here! Do not try any of this unless you have the right equipment and the know-how!
We should think about a handbook section on battery load testing. Anyway it depends on whether it must be AC but I'd expect a heating element wouldn't care between AC and DC.
One of the load testers I have is meant for 12v car batteries and it's simply a heating element.
Richard Hatfield has in his garage an interesting contraption for load testing. FWIW for ad-hoc load testing it's enough to have a fixed resistor-like widget to dump current into. But for more official load testing the resistance of the load has to vary over time because an official load test keeps the current rate the same throughout the test. The gizmo in Richard's garage is a long tube that can run a cooling fluid through it, one lead is connected at the bottom of the tube, and the other connected to this roller gizmo that can roll up and down the tube easily. The resistance of the load depends on how far down the roller gizmo is located at any moment, which lets you adjust it during a load test to keep the amp rate constant.
FWIW I have seen pictures of portable AC heaters used as load tests of DC batteries.
I have been using every thing under the sun for load testers. It makes good sense to use 200 to 240 volt resistive and Halogen heaters as load testers. They last for ever and ever on batteries. For 12 volt I use Harbor Freight 50 and 100 amp load testers and for really heavy loads I use an Inverter hooked up to a 1200 Watt heater. Reason there is most inverters turn off at 10. to 10.5 volts and can't ruin a 12 volt battery. For my VX-1 is use and Anderson SB-50 and it serves to measure pack voltage and run my tools. I have an SB-50 to NEMA 5-20 adapter cable. BTW I even mow the lawn with 125 volt DC. Even PTC heater work on DC also. They are those EV heater made from bathroom heater cores. In my house I use 240 volt resistive heaters on 120 volt to give me 1/4 power / heat. A 240 volt 2400 /2500 watt heater makes 600 watts of heat on 120 volt. Half the voltage and half the current = 1/4 the power.
It makes perfect sense to use a Halogen heater as load. Best load test around too.
I should of said something like that about switching. I thought you were just going to use an Alligator clip and load test for a few seconds or a minute. I use an SW-80 contactor for magnetic blow outs to turn on and off load for my heater in my truck. Power for SW-80 is a DC-DC converter inside to power coils. For my larger load tester I use a reversing switch wired in series to give more distance inside contacts. Using a 10 Amp load sure doesn't take long to find bad cells. In USA the standard joltage is 100 to 125 volt stuff and most AC type switches weld almost instantly. But local electrical supply houses here like Standard Electric order me 250 volt switches that even are rated for DC. If you do use alligator clips to load test, then do connections fast or it can draw an arc very fast. For some reason Halogen heater make a faster arc than Ni-Chrome wires in heaters and both are great for load testers. I think because of filament type glow making faster heat.
Also same thing using fuses too. Those puppies got to be rated for DC. Use ANN-50 for fuses for Bussman has a lot of DC rated fuses. Semiconductor fuses are good too for DC.
I use a lot of tools on DC and all of our vacuums are welded switches because I keep forgetting to unplug vs switch it off.Some of the tools I use are Craftsman 3.0 HP table saw, Skill Saw, Jig saw, router, air compressor, and all of my drills work fine on DC. I mean great really. I even read the label on some tools and it says AC or DC.