Energizer C Rechargeable (NiMH) — Reliable C-Size Power You Can Refill

Energizer C Rechargeable batteries are Nickel-Metal Hydride (NiMH) cells designed for devices that need hours of steady power. They ship ready to use, maintain charge well in storage, and can be recharged hundreds of times to cut waste and costs over disposable batteries.

What They Are

• C-size NiMH batteries, nominal 1.2 V per cell
• Low self-discharge (arrive pre-charged; retain charge in storage)
• Typical rated capacity varies by version; check packaging (often around 2500–3000 mAh)
• Compatible with most smart NiMH chargers that physically support C cells

Best Uses

• LED lanterns and emergency lights (steady brightness for long sessions)
• Portable speakers/radios (predictable set lengths, fewer dropouts)
• Educational robots and motorized toys (handles start-up current well)
• Inspection/work lights (reliable runtime on medium modes)
• Older flashlights designed for C cells (modern performance without disposables)

When to Choose Them (and When to Skip)

• Choose if you use the device weekly or seasonally and want predictable runtime with refillable power.
• Choose for gear that draws a steady current for hours (lanterns, speakers, work lights).
• Skip for devices stored untouched for years with no charging plan (use primary alkalines kept fresh and rotated).
• Skip if the device requires a different chemistry/voltage (e.g., specialty lithium packs) or strict 1.5 V behavior (rare—test first).

Runtime Planning (Simple and Practical)

Use this quick estimate for series packs (most multi-cell devices place cells in series so mAh does not add):

• Runtime (hours) ≈ (Battery capacity in mAh ÷ Device draw in mA) × 0.8–0.85

Example: A lantern drawing 250 mA on medium, with 2500 mAh C cells → 2500 ÷ 250 × 0.85 ≈ 8.5 hours.

Tip: If one session often runs close to empty, carry one spare labeled set and swap at the first sign of dimming.

Charging: Get It Right

What to Look For in a Charger

• Independent bays (each cell charges/terminates on its own)
• Smart termination (delta-V and/or temperature sensing)
• Moderate per-bay current for C cells (500–1000 mA is a good everyday target)
• Clear status indicators (per-bay LEDs or an LCD)

Charge Time Shortcut

Charge time (hours) ≈ Capacity (mAh) × 1.2 ÷ Charge current (mA)

Cell Capacity	Charge Current	Approx. Time
2500 mAh	500 mA	~6 hours
2500 mAh	800 mA	~3.8 hours
3000 mAh	1000 mA	~3.6 hours

Cells should finish warm, not hot. If a bay errors repeatedly with the same cell, retire that cell and keep sets matched.

Setup for Predictable Results

• Keep matched sets: Label pairs or quartets (for example, “Lantern A – 1/2/3/4”) and cycle them together.
• Swap on dim, not dead: Extends life and avoids deep discharge.
• Top off before trips or storm season; for storage beyond a month, top off monthly.
• Maintain contacts: Wipe battery ends and device springs with a dry, lint-free cloth during swaps.

Alternatives & Compatibility Notes

• Alkaline C cells: Fine for very infrequent use if you track expiration dates; performance sags under sustained load.
• AA-to-C adapters: Acceptable for low-drain devices; not ideal for motors or bright lantern modes.
• Device voltage: Most products labeled for 1.5 V cells work well with 1.2 V NiMH because NiMH holds voltage under load. If uncertain, test one set first.

Safety & Care

• Use only NiMH chargers that fit C cells; do not mix chemistries in a device.
• Insert with correct polarity; do not short or crush cells.
• Store cool and dry (ideally 40–77 °F / 5–25 °C).
• Recycle responsibly at end of life.

FAQ

Do 1.2 V NiMH C cells work in devices that expect 1.5 V?

In most cases, yes. Because NiMH voltage stays flatter under load, you often get steadier performance. If a device is unusually sensitive, test one set first.

How many recharge cycles can I expect?

Hundreds, assuming moderate charge rates, cool storage, and matched-set use. Frequent hot fast-charging shortens life.

Are they pre-charged?

Yes, they arrive ready to use. Top off if they have been in storage for several months.

What charger current should I use?

500–1000 mA per bay is a good everyday range for C cells. Higher currents reduce charge time but increase heat and wear.

Can I mix old and new cells in one device?

No. Keep sets identical in brand, capacity, and age for stable runtime and to avoid premature failures.