A portable fridge-freezer earns its place on a family weekend only if it is already cold when you load it and still powered when you arrive. Most of that work happens at home the night before, on wall power, and none of it is complicated once the order is settled. Below: five setup steps in order, why that order holds, a first-use run, what fits in 37 quarts, where the unit sits in the vehicle, a do-and-don't table, a short Q&A, and a closing recommendation.
Step 1: Pre-Chill the UR35W at Home on Wall Power
Plug the Explorer Bear UR35W into a household outlet the night before you leave. It runs on AC 100–240V, and household AC is the one supply that costs you nothing once the trip starts.
It chills fast. The LG compressor brings the interior from 77°F to 32°F in 15 minutes, so the unit is ready long before you are. Give it the evening anyway: the UR35W draws under 0.5 kWh/day even in MAX mode, and cooling it at home keeps that draw off your vehicle entirely.
The walls and the interior fittings hold cold too, not just the air, so a unit that has been running for hours starts the drive in better shape than one switched on in the driveway. An overnight run also gives you time to catch a fault. A unit that has not reached its setpoint by morning is something you want to discover in your kitchen.
Step 2: Charge and Install Both 170 Wh Batteries
Off-grid operation requires two batteries, and the base unit ships without them. Install both packs before you load any food, because each 170 Wh pack installs and charges through the fridge itself while the fridge runs on 110V AC or 12/24V DC.
That makes the pre-chill and the battery charge one job rather than two. You need no separate charger, and the packs take no additional car space to charge, since they ride inside the unit they power. Leave both installed and on wall power until you actually drive away.
There is a practical reason to seat the packs before the food goes in: loading first means lifting a full unit to reach them.
Step 3: Load Frozen Food Frozen, Chilled Food Second
Move frozen items straight from your home freezer into the cold unit. The UR35W's quick cool-down describes a chill rather than a freeze-down, so plan on it holding what you hand it rather than freezing a warm load for you.
USDA FSIS guidance sets what "keep it frozen" has to mean over a weekend: food stored constantly at 0 °F stays safe indefinitely, and only quality suffers over lengthy freezer storage. The FSIS freezer storage-time chart assumes a 0 °F freezer. That benchmark applies for the whole trip, not only at the moment you close the lid, so how you load the unit and how you power it are one decision.
Load the frozen block first and put the drinks, fruit, and snacks your kids reach for above it — the less digging, the less time the lid spends open.
Step 4: Set the Mode Before You Leave the Driveway
Choose the setpoint at home, while the unit is still on wall power, so it reaches temperature before the drive instead of during it. The batteries do not treat the two settings alike.
On two 170 Wh packs the UR35W is rated up to 16 hours at -4°F and up to 48 hours at 40°F. Pick the colder setting when the load genuinely has to stay frozen, and the fridge setting when it does not. You can change the setting at the trailhead, but the pull-down then runs on battery instead of on the wall.
Step 5: Keep the UR35W Powered in Transit
Run the fridge from the vehicle's 12V or 24V supply for the whole drive, not just for the highway stretch. The installed pack charges through the fridge while it does, so the drive doubles as a charge and the unit never has to restart cold at the site.
The UR35W accepts AC 100–240V, DC 12V/24V, battery, or solar. That gives you four ways to keep it fed between the driveway and the campsite, and vehicle power is the one that keeps the packs in reserve for the site itself.
Why the Order Matters
Pre-chilling and charging both run on household AC, so they belong to a single overnight rather than to two separate errands. Food goes in after the unit is cold, because the UR35W holds a temperature rather than pulling a warm load down to a freezer setting.
The setpoint gets chosen at home for the same reason the pre-chill does: wall power should pay for the pull-down. Only the DC lead is genuinely a departure-day task, and it is the one that keeps the installed pack topped up while you drive.
First Use: Run the UR35W Once Before the Trip
Schedule the trial run for a weeknight, not for the morning you leave. Run the unit through a full cycle on household AC with both packs installed, and confirm three things: that it reaches the setpoint you chose, that the packs charge through the fridge while it runs, and that your vehicle's DC socket actually carries it.
The DC socket deserves a real test rather than an assumption. The UR35W's working power is 38~40W, which is modest, but a socket that dies with the ignition leaves the fridge on battery every time you stop. Find that out in your own driveway.
What Fits in 37 Quarts for a Family Weekend
The UR35W holds 37 qt / 35 L inside. That space takes up to 50 cans or 40 12 oz bottles, which stays the cleanest yardstick for volume even when you are packing food rather than drinks.
A family load trades most of those cans away. Two or three days of meals for four, with a frozen core and one day of drinks, will generally fill it without much room to spare. If your weekends run longer than three days, or your group eats mostly from the frozen side, plan on a restock rather than on fitting the whole trip in at once.
Where the UR35W Sits and Which Way the Lid Opens
Settle the placement before the unit is loaded and heavy. The UR35W measures roughly 24.6 x 15.5 x 17.3 inches and weighs 33.7 lb, and one owner reports it fits between the two front seats of a Sprinter van.
The lid is reversible, which another owner calls out as a practical touch. Decide the hinge side against where the unit will actually live, because a hinge on the wrong side is awkward to change once the unit is wedged into place.
Do and Don't for a UR35W Weekend Setup
| Do | Don't |
|---|---|
| Pre-chill on household AC the night before you leave. | Start the pull-down in the driveway and hand the work to your vehicle. |
| Install and charge both packs while the unit is still on wall power. | Set off with one pack, since off-grid operation requires two. |
| Load food that is already frozen. | Expect the unit to freeze a warm load for you. |
| Choose the setpoint before you drive. | Run the freezer setting for a load that only needs chilling. |
| Keep the fridge on 12V or 24V for the drive, which charges the installed pack. | Unplug at every stop and let the interior warm between legs. |
| Settle placement and hinge side before the unit is loaded. | Wedge the loaded unit into a gap you have not measured. |
Questions About Setting Up the UR35W
Can the batteries charge phones on the trip?
Yes. Each 170 Wh pack carries Type‑C and USB power bank outputs, so it works as a power bank for phones and small devices. Decide in advance how much of a pack you are willing to spend that way, since the same pack is what keeps the fridge cold once you are away from the vehicle.
Do the packs work with other fridges?
No. The Explorer Bear 170Wh Portable Battery is built for Explorer Bear UR series refrigerators, and it installs and charges through them. Treat it as part of the fridge rather than as a general-purpose power station.
Is the UR35W quiet enough to run near sleeping kids?
Owner feedback on the UR35W consistently praises how quiet it is in real use, and the LG compressor produces less noise. Treat noise as a fit question rather than a spec, and weigh it against where the unit will sit overnight and how lightly your family sleeps.
Can it keep running from the car with the engine off?
The UR35W runs on DC 12V/24V from the vehicle and on its own 170 Wh packs, and which one you leave it on with the engine off is a decision about your starter battery. The packs exist for exactly that gap: they add off-grid runtime when external power is not available. That argues for setting off with both packs charged.
Final Thoughts on a Family Weekend Setup
One variable decides your setup: whether the UR35W ever leaves a power source over the weekend. For a powered site, or a vehicle you drive every day, the Plug-in Unit Only configuration generally covers it, and a site with no hookup wants both batteries, which is what the 1 Unit + 2 Batteries Combo ships with. Across those two configurations the UR35W runs $349.00 to $549.00. Either way, the night before does most of the work. Compare the UR35W's own numbers against the weekend you actually run, and explore the Explorer Bear 170Wh Portable Battery if long stretches away from power are normal for you.
