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Optima’s Digital 400 Battery Charger/Tender

Battery-Tending Made Easy

One of the worst things you can do to a vehicle is let it sit. Vehicles are meant to be driven, not collect dust. The reality most of us face is far different from the dream world in which we would like to live. You know, the one where time and money is always in great abundance.

If you’re like us, your trail toys often get parked for long periods of time. While swapping out fluids is standard issue on any rig that has been set aside for an extended length of time, changing out the battery shouldn’t be part of the refresh cycle. The battery-saving solution for most of us is a simple battery tender. While conventional 12-volt chargers and battery tenders are great for keeping your rig’s battery alive, not all are designed to handle the more specialized dry-cell batteries.

As is the case with all things electronic, charger technology has changed greatly over the past decade. Where mini-fridge-sized roller-chargers used to be the norm, we now use much smaller battery boosters. Always up for testing new technology, we got our hands on an Optima Batteries handheld 12-volt tender/charger, which the company calls the Digital 400. Given Optima’s line of AGM (a.k.a. dry cell) batteries, the company crafted the Digital 400 battery charger to support its series-specific Red, Blue, and YellowTop battery line.

Since the Digital 400 battery charger comes with two terminal hook ups (terminal clamps and eyelets), we wired ours directly to our Jeep Wrangler TJ, which is fitted with an Optima RedTop battery. Each Digital 400 adjusts for ambient air temperature during charging and features over-temperature protection. The included case also doubles as a wall mount, so hooking up the system is easy.

Using a 120-watt outlet, the Digital 400 offers a charge rate of up to four amps on large batteries and three amps on small batteries. In addition to juicing the Optima-specific batteries, the Digital 400 is designed to work with standard flooded 12-volt batteries. To choose the battery type you want to charge or tend, simply press one of the four categorized 12-volt battery options on the front of the case. When you need to use the charger for another battery, just unclip it from the mount. It even has a built-in hanger so you can set it out of harm’s way.

Yes, the Digital 400 battery charger is bit more expensive than a basic charger you might find at your local parts store, you do get a lot for your money. The fact that it charges and conditions Optima series-specific batteries and provides an actual digital readout of the batteries amps and volts is excellent. There is also a percentage light scale, so you can see how far along the battery is and when the charge is complete. A combo LCD and LED screen is easy to read, and the device is operator friendly.

Overall, the Digital 400 battery charger has been a very durable and useful tool in our garage over the past year. Battery tenders have always been a necessity we often wish we didn’t need, but it’s a product that ultimately saves us money and time. So, if you’re looking for a new charger for your 12-volt toys, we say the Digital 400 battery charger is definitely worth a closer look.