'Northern Lights'....of a different sort.

We are in northern Minnesota and it's relatively common to have stretches of winter days not exceeding 0 degrees F with lower temps at night.  My wife feeds several animals that have different housing and feeding locations, some of which are illuminated during night feeding with building-attached floodlights.  A few are fed more remotely....and wife is wanting now to have lighting available for no more than a few hours each night at those feeding  stations.  The desired solution would be solar-charged, battery-driven LED lights that can withstand the cold temperatures.  Midwinter sun is ~6-7 hours, but rarely optimal and the feeding stations additionally will have some occlusion of the incident light by (leafless) trees, etc.  This lighting need does not need to be very bright,--just something so she can scan the feeding stations during the great meal and make sure no animal is wandering over to steal another's meal.  I've suggested just using the Dewalt tool system and use their rechargeable batteries to operate a few of their work-lights, but she'd rather have something stationary/semi-permanent that can be turned on/off during feeding (prefers not to have motion-sensing).  Most of what I've seen scanning the internet either does poorly in cold weather or is of a municipal grade street-light (which would be overkill). Does anyone here in a northern or otherwise cold setting have experience with such lighting that can withstand the cold temperatures on the batteries and charging/electrical components?  Thanks!......

The trick would be to stick to a lead acid chemistry. Both nickel metal hydride and lithium  do not charge in the cold. A small lead acid battery, a 12 volt panel and a small charge control will take care of the battery end. Lots of 12 volt light options.

All of my solar lights are performing poorly given the low sun angle and short daylight hours at this time of year. It's not a problem, it's what I  expected as situation normal for the conditions. They are designed for a different latitude. Both NiMH AA's and Li-ion 18650 batteries are struggling, even though our temperatures have been mild. Not enough direct sunlight -- it's that simple.

But your Taskmaster has handed you a pretty tall order! This has been known to happen.

How far apart are these feeding stations? Can they be fed from a single off-grid hub? That would be efficient, and practical.

Would your Taskmaster consider carrying replacement battery packs that are fully charged and easily plugged in at the various stations? That could also be more efficient than a ton of solar panels and batteries in situ.

For me, I would wire up a cheap LED automotive ATV floodlight on a pole, which can handle 12 to 24 VDC, and as a switch use a 60-minute mechanical "bathroom fan" timer. The battery can be anything you like, from a 12V lead acid with panel and controller to an 18V li-ion drill battery that you retrieve and charge in the warm shop.

David Baillie wrote:The trick would be to stick to a lead acid chemistry. Both nickel metal hydride and lithium  do not charge in the cold. A small lead acid battery, a 12 volt panel and a small charge control will take care of the battery end. Lots of 12 volt light options.

Well, those chemistries sort of charge. Better if in a protected area. Not ideal in winter though. And not good for the cells either. I pull them out and cycle them vigorously to restore capacity.

Lead-acid is still the champ in the cold. One station with solar panels and a big deep cycle battery will last a lot longer and ultimately cost less than a bunch of dinky installations. Build a hub and distribute from there, I think.

Headlamps are the most efficient for this in my experience living off grid for several years. The also do not destroy my night vision nearly as much as other lights. It may not satisfy the boss though, and I know that is often more important than other practical considerations.

Excellent responses.....thank you both!.  Yes, given the proximity of the two remote feeding stations to each other, it probably makes more sense to have a single, larger PV/battery/controller hub with distribution to 2 -3 lights (12V/LED).  As Douglas noted, the sun angle and duration is not helping, but it could be worse than our location and we can be glad to be getting 4 hr of solid sunlight (clear day) on a day that is now ~ 8 hr sunrise to sunset.  PV panels are relatively plentiful and affordable on FB Marketplace and Craigslist, so oversizing the panel a bit and letting the controller play traffic cop may be the solution here.  And it makes sense that lead acids are still the robust kids on the block since they are the ones sitting in my neglected cars, truck, and tractors and still providing starting current. Fortunately as you guys indicated, lots of 12V lighting options out there.....automotive and ATV-style floodlights may be best and hopefully some will come with a bit more diffuse light as well.  I think I will rig it up as somewhat suggested....a battery powerful enough to drive the system, but possibly small enough for easy recovery to a warm building during the worst low temperatures.  (I will be the one shuttling battery to and fro....she has enough power drain at her age already given the amount of animal care she is providing to her charges.)  Given that one puts a battery charger directly on a a dead vehicle still sitting in the cold (not to mention the charging system of a cold, just-started vehicle), I suspect charging a cold lead acid battery is still okay, yes......i.e., it does not needed to be pre-warmed before beginning the charging cycle.

Thanks....I hope to draw up the proposal and submit it to the "Taskmaster" for review :-)