Nickel-Metal Hydride (NiMH) Battery Chargers

What to look for

• Cell count and pack voltage. NiMH nominal voltage is 1.2V per cell. Match the charger to the fully-charged pack voltage (cells × 1.4V) — a mismatch will either never terminate or damage the cells.
• Charge current. Fast chargers run at 0.5C–1C with proper termination. Overnight chargers run at 0.1C and are safe for indefinite cycling.
• Termination method. Look for -ΔV (voltage drop), dT/dt (temperature rise) and a safety timer — all three protect the pack if any single method mis-triggers.
• Replacement for NiCd. If you're modernising a legacy NiCd application, confirm the new charger supports NiMH chemistry — the two profiles differ.

Frequently asked questions

Can I use a NiCd charger on a NiMH battery?

Not reliably. NiMH cells have a much smaller voltage drop at full charge than NiCd, so a NiCd-only charger may fail to terminate and overheat the pack. Use a charger explicitly rated for NiMH (or dual-chemistry NiMH/NiCd) with proper -ΔV or dT/dt termination.

What is -ΔV charge termination?

-ΔV (delta-V) termination detects the small voltage drop that occurs at the top of a NiMH cell's charge curve and stops the charge immediately. Combined with a temperature sensor and safety timer, it prevents over-charge damage.

How long does a NiMH battery take to charge?

A fast charger at 1C completes a full charge in around 1–1.5 hours. A standard 0.1C overnight charger takes 14–16 hours and can safely stay connected without damaging the cells.

Do your chargers work with rechargeable AA and AAA cells?

The Mascot range in this category is aimed at professional multi-cell packs rather than loose consumer AA/AAA cells. Contact us with your pack configuration and we'll recommend the correct model or specify a custom charger.

Can I charge NiMH batteries in cold or hot conditions?

NiMH cells charge best between 10°C and 35°C. Our chargers include temperature monitoring to suspend charging outside safe limits, protecting the pack in field or outdoor deployment.