March 4, 2026
Battery beef: Nickel vs Lithium
Charging a three-cell nickel-based battery pack with a Li-Ion charger [pdf]
TI suggests charging nickel batteries with lithium chargers — fans cry foul
TLDR: TI suggests using a lithium-ion charger to power nickel battery packs, sparking debate over safety and smarts. The community’s loudest take: industry neglects NiMH, forcing slow charges and hacks, while fans argue nickel’s safety and affordability deserve modern support.
Texas Instruments dropped a spicy idea: use a common lithium-ion charger chip to juice a three-cell nickel battery pack. The moment the TI PDF hit tech circles, the comments lit up with a familiar split. Some tinkerers cheered the hack—“use what’s cheap and available!”—while purists clutched their AAs, arguing you shouldn’t “make nickel pretend it’s lithium.” The strongest mood? Frustration that nickel-metal hydride (NiMH) still gets ignored by modern charger makers, despite being safer, cheaper, and easy to replace.
User kdklol summed it up: dedicated NiMH charger chips “basically don’t exist,” so most devices trickle-charge slowly and call it a day. Meanwhile, the TI piece explains why this is even a debate: lithium chargers do constant current then constant voltage (hold the volts, taper the amps), while nickel likes a precise peak-detect method (blast steady current, stop when the voltage drops). The drama: can you safely use the lithium method on nickel packs without overcooking them? Pragmatists say yes, with trade-offs; purists say no, get a proper nickel brain.
Memes flew: “Nickelback vs Lithium,” “Grandpa’s AA gang vs smartphone batteries,” and the evergreen “NiMH is the cockroach of batteries—still here after the apocalypse.” Bottom line: this isn’t just a charger debate—it’s a culture war over what kind of batteries deserve real love.
Key Points
- •The article proposes using a single-cell Li‑ion charger IC to charge three-series nickel-based battery packs due to limited modern nickel charger IC options.
- •Nickel batteries require CC fast charging between 0.3C and 3C and terminate via peak-voltage (−ΔV) detection of ~3–6 mV per cell.
- •Li‑ion chargers follow a CC‑CV algorithm: constant current until 4.2 V, then constant voltage with taper-current termination at about one‑tenth of fast‑charge current.
- •Li‑ion charger termination based on taper current (ITERM) creates challenges when used for nickel cells that rely on −ΔV termination, requiring careful design considerations.
- •NiMH cells typically reach ~1.55 V before termination and relax to ~1.45 V afterward; precise sampling is needed to detect the small voltage drop at full charge.