250 es / sx light question. Need battery?

[tri again]

One with No battery...I THINK my neutral light comes on when it starts and runs but can't seem to find 12 volts to run headlight.
I know with my trail 90, the battery cables need to be jumped together with no battery in the loop.

so wondering if I need a battery in the harness, even if it's dead, in order to get lights.
Also have a wickedly chopped sx that runs great but all the wires were cut and hacked except for ignition. I put a volt meter on all the wires I could find when it's running, but can't find 12 volts anywhere.
That one also has no battery.
Nasty time of year to work outside so I appreciate any suggestions.
Also not fun at all holding a flashlight to run the camp when it's dark 16 hrs a day.
Thanks and hope everyone is doing ok with this weather.
Just thanking the gods I ignored the folks making fun of us when we were processing firewood at 90+ degrees last summer.

[Jmoozy27]

I don't think the 250's need the battery to run the lights. I will check when I get around my BR tonight. I want to say that if it has a key turned to the on position and motor running that the alt should run the electronics.

[Pickup_man]

I agree with Jmoozy, if it runs without the battery, the battery shouldn't be required to run the lights. Sounds like an electrical gremlin to me.

[Gearheadtom]

The lights on my SX will work without the battery, but they work weird, any e-start 200 is the same. The lights are bright at idle, but dim out when you give it gas.

[Flyingw]

The ES and SX are designed to run lights off the battery much like your car does. Take the battery out of the equation and the lights don't illuminate when the engine is off obviously and when the engine is running are working off the DC tap that comes from the regulator. The reason the lights dim when you rev it is, the output from the regulator trims down so to speak with increased RPMs not the other way as you would think. Running the trike with no battery is hard on the lighting circuit. With no battery there, the regulator thinks the battery is low and is trying to charge it so the regulator is outputting DC power all the time instead of occasionally when the battery power level drops below a certain point. My advice, if it is intended to have a battery, put one in.

[Jmoozy27]

I definitely agree with that, spend a little extra for a decent battery too, it's worth the extra dime.

[tri again]

Yeah, these 2 trikes came that way so maybe the regulators are burnt.
They both run great but I just can't find 12 volts on any of the wires to run a headlight.
I PROmise I'll put batteries in them...well, the sx need a full harness first.

Thanks everyone.