A long as the engine is running while pulling, should be no problem. Also as was mentioned, winch needs time to cool, and that will give the battery time to recharge. Some folks use a bit of bicycle cable and a shifter to raise the idle up hand/foot free.
Chicago Electric 8000lb and a single Walmart starting battery. I do leave the engine running while winching. Dragged out three vehicles in a row once and the winch was running the same at the end as the beginning.
I Ran a Warn M10000 with a single Optima Redtop for 5 years with no problems on my old FJ60. Always tried to have it running on high idle when winching, but there were a few times gravity didn't allow it, and it still worked fine. The set up came off my old Ramcharger which ran dual redtops, and performance wise there was no real difference, except the obvious advantages of duals.
I don't know if this is applicable on a Toyota, it works on an Jeep, but I have found that placing a penny or a nickle under the throttle cam thingy brings my RPMs, depending on which I use, up to about 1500-1800 where the alternator is actually producing some power as opposed to idle where it is making crap for amperage... I call it the $.05 throttle lock... It makes the voltage drop significantly less when I winch or use the compressor on my Warn Powerplant. YMMV
broken1, love the simple way! Putting a spacer between the throttle cam and stop screw would work fine to bump the idle. OTOH, my truck's throttle body has a provision for a hand throttle cable, so it's an easy thing to add. One feature of the old Toyota pre-Tacoma trucks is they were designed and built for use all over the world, places where winches and bull bars are factory options...
I see two folks are using the Optima Red Top with success. So I went to Optima's web site and see that they now recommend the Yellow Top as their site says:
Demand More from Your Vehicle?
The YellowTop® high-performance AGM battery is one of the only true dual-purpose automotive batteries available. With premium cranking power and unparalleled cycling capability (rechargeability), it is perfect for modern accessory-loaded vehicles. The YellowTop can repeatedly bounce back from deep power drains to full energy capacity, so it can power plenty of electronics and still start you up time after time. Lower internal resistance also provides more consistent power output and faster recharges.
Trucks with winches, vehicles with multiple electronics, cars with high-demand audio systems, commercial vehicles and heavy equipment all rely on this battery to provide ultimate starting and deep cycle power.
An experienced mechanic we used in Arizona told us once that if we replace a battery every three years regardless of how it is acting we would not be disappointed and much less likely to get stranded with a bad battery. We've done that, and with that advice haven't had a battery failure on the road. With the Optima that would be a much more expensive habit to maintain.
I like the idea of increasing idle speed when winching but with the 2006 Tacoma is that possible with not having direct pedal/throttle speed connection?
I ran a Yellow top as my starter/ accessory / winch battery for a couple years, without issue, now I run 2 yellows in series. I'm working my way up to a management system. For now my system works great.