Battery Tender 12-Foot DC Charger Extension Cable, Black

Sometimes the battery is just too far from where you can plug in. That's the whole problem this Battery Tender 12-foot DC extension solves. It adds twelve feet between your charger's output lead and the battery connection, so you can leave the charger somewhere convenient and still reach the bank that needs the charge.

We sell a lot of these to boaters, and the reason is simple. On a lot of boats the shore-power inlet, or the spot where you can safely set a charger, is nowhere near the batteries. Think center console with the batteries up forward and the inlet back at the transom. Or a trawler where the charger lives in the engine room and the house bank sits a compartment away. Twelve feet of extra reach turns an awkward run into an easy one.

It plugs straight into the quick-disconnect lead that came with your Battery Tender. Male on one end, female on the other, so it drops right in line between the charger pigtail and the ring terminals already bolted to your battery. No cutting, no crimping, no rewiring. You unplug the existing connection, put this in the middle, and you're done.

Here's the part to get right before you buy. This extension uses the standard black quick-disconnect plug, so it fits the Battery Tender Junior, Plus, 2, 4, 5, and the 10-Bank units. It does not fit the 6-volt Battery Tender Plus, and it won't mate with any older Battery Tender that uses the white quick-disconnect plugs. If your charger's connector is white, this isn't the cable for you. Check the plug color before you order and you'll save yourself a return.

A few notes from installs we've seen out on the water. Salt air is hard on any connector, so a dab of dielectric grease inside the plug before you snap it together goes a long way toward keeping corrosion out after a season. On smaller runabouts the cable can feel a little stiff for a really tight battery box, so plan your route and give it a gentle bend rather than forcing a sharp one. And on any longer run, tuck the cable up and cable-tie it so it isn't rubbing against a bulkhead or a fuel line every time the boat pounds through a chop.

One honest word on charging over distance. Any time you add wire between a charger and a battery you add a little resistance, and that shows up as voltage drop. For the trickle and maintenance charging these Battery Tender units are built for, twelve feet is well within reason and you won't notice a real difference. If you're pushing one of the bigger multi-bank units near its top output, just know a long run costs you a hair of efficiency. Some folks add a small inline fuse near the battery end on longer installs for peace of mind. That's optional, not required.

This isn't just a boat part, either. Plenty of folks run these on motorcycles, ATVs, classic cars, and lawn equipment that sit parked through the off-season. The idea is the same. Mount the ring terminals on the battery once, leave them there, and route this extension out to a spot where you can reach a charger without contorting yourself over the machine. Come spring, you plug in and go.

If you run more than one battery, the 10-Bank unit plus a couple of these extensions makes for a tidy setup. You can keep the charger mounted in one place and fan the leads out to each battery, so nothing gets moved or unplugged all winter. That's the kind of small upgrade that saves you a dead battery come April.

It's black, it's twelve feet, and it does exactly one job well. If your charger sits too far from the battery, this is the cable that closes the gap. Keep one aboard and you can charge from wherever the power actually is.