Discover Battery’s Lithium Blue LiFePO4, a premium drop-in
Discover Battery has been in the battery business since 1949, so they’re not new to the challenges of building batteries. They’ve recently begun distributing their Lithium Blue LiFePO4 battery in the U.S. and I’d say their experience shows in the quality of the product they’re delivering. Let’s take a look at what these batteries offer and how they’re different from what’s already available.
Discover’s first U.S. offering is their Lithium Blue line of LiFePO4 batteries. All Lithium Blue batteries have built-in Bluetooth radios to view your battery’s status via an app on your phone. The batteries are available in either group 24 or GC2 sizes. The group 24 batteries come in 12 (100 amp hour), 24 (45 amp hour), and 36-volt (30 amp hour) configurations. The GC2s are offered in 12-volt, 200 amp hour or 24-volt, 100 amp hour configurations. I’m not sure why the higher voltage G24 batteries lose a few watt hours of total capacity.
Lithium Blue batteries include a Bluetooth radio which, in conjunction with their app, shares information about the batteries. The app provides insight into the battery’s state-of-charge, voltage, current consumption, and temperature. Plus, in the event of a fault the app provides information on the fault. I think that last part is a big deal compared to most drop-in batteries without any mechanism to provide fault information.
Discover is positioning Lithium Blue as a quality battery at a reasonable price point. They produced a teardown video showing the differences between their batteries and the competitors. The video does a nice job showing what makes the Lithium Blues different. I believe the one in the middle is a Relion RB100 and I’m pretty certain the blue and gray battery is a Battle Born 100 amp hour battery.
Watching the video the biggest takeaway for me was the amount of engineering Discover put into making a better battery. The battery case is designed to be opened, the battery management system (BMS) is in the lid of the battery, and the cells of the battery are replaceable. Placing the BMS in the lid allows for easy replacement of the BMS in the event of a fault. Plus, with the BMS in the lid, the top of the battery is a heat sink to allow passive cooling of the BMS.
The user-replaceable fuse on the top of each battery enhances safety and helps protect the BMS. Unlike many batteries on the market, the use of a separate, easily replaced fuse ensures a fault is quickly disconnected. Also, the built-in, suitcase-style handle makes moving the batteries around easier. I really appreciate the comfortable and easy-to-grip handles on my Mastervolt MLi batteries.
The Discover batteries use prismatic cells instead of the cylindrical cells competitor batteries use. Compared to similar capacity competitors, the Lithium Blues are smaller and I suspect that’s mostly because prismatic cells’ space efficiency.
Like many other LiFePO4 batteries, Discover advertises these as drop-in batteries. The natural assumption is that means these are drop-in replacements for lead-acid batteries. But, that doesn’t really tell the full story of a lead-acid to lithium conversion. A proper conversion requires modifying the charging system as I’ve done for Have Another Day’s move to lithium. Discover’s manual recommends against charging with lead-acid charging profiles and lists requirements like no equalization or temperature compensation. I recognize that drop-in is an industry-wide term, but I think it’s an inaccurate term that creates confusion.
In addition to the Lithium Blue batteries, Discover has also announced Lithium Pro batteries with higher charge and discharge limits and external BMS communication. The external BMS communication will allow paralleled batteries BMSes to communicate with each other as well as allowing the BMS to communicate with connected inverters and charging equipment. The 120 amp hour, 12-volt, GC2 battery will support 200 amp continuous discharge. At 1.667C it’s among the highest discharge ratings I’ve seen for drop-in batteries.
I’m hoping to have the opportunity to test some of these batteries myself in the near future. Many of the features of these batteries remind me of the Mastervolt MLi series of batteries (with the notable exception of no CAN communication for Discover Blue batteries) at a price point that’s competitive. I’m looking forward to testing them and seeing if they’re as good in use as they appear on paper and in videos.