# Trickle charger

> Low-current charger (1-3 A) that keeps the battery at 100% indefinitely. For cars or motorcycles parked for months.

**Categoría**: Maintenance & use
**URL canónica**: https://baterias.com/gb/battery-glossary/trickle-charger
**Idioma**: en-GB

## Definition

A trickle charger is a low-current charger (typically 0.8 to 3 A) designed to **stay permanently connected to the battery and keep it at 100% SOC** without overcharging. It works by alternating absorption and float phases automatically based on the detected voltage. Suitable for: occasional-use vehicles (second car in the garage, classics), motorcycles in winter, motorhomes and boats in storage, solar back-up batteries. **It prevents sulphation and multiplies battery life by 2-3×** for a battery that would otherwise sit discharged for months. Reference models: CTEK MUS 4.3/MXS 3.8, Optimate 4, NOCO Genius 1/2. Cost: £40-80, easily amortised by avoiding even a single premature battery replacement (a new battery costs £100-200). Some modern vehicles with high parasitic loads (alarm, GPS, keyless entry) drain the battery in 3-4 weeks — for these a trickle charger is practically essential if the car will be parked longer than that.

## See also

- [Smart charger](https://baterias.com/gb/battery-glossary/smart-charger)
- [Sulphation](https://baterias.com/gb/battery-glossary/sulphation)

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