Proper charging is the single most important factor in battery longevity. This guide covers charge controller selection, wiring, and the correct voltage settings for each battery type.
MPPT vs PWM: Which to Choose?
- PWM (Pulse Width Modulation): Simpler, cheaper. PV panel voltage must match battery voltage. Efficiency 70–90%. Suitable for small systems where PV voltage closely matches battery voltage.
- MPPT (Maximum Power Point Tracking): Extracts maximum power from PV panels. Works with any PV voltage. Efficiency 94–99%. Recommended for all systems above 200W.
Charging Stages
- Bulk stage: Maximum current until battery reaches absorb voltage. Battery recovers rapidly.
- Absorb (topping) stage: Constant voltage. Current tapers as battery fills. Critical for full charge.
- Float stage: Reduced voltage maintains full charge without overcharging. Compensation for daily use.
- Equalize stage: Periodic controlled overcharge (flooded batteries only). Corrects cell imbalances.
Correct Voltage Settings for CHISEN OPzV (48V system)
- Bulk/Absorb: 57.6V (14.4V per 12V equivalent)
- Absorb time: 2–4 hours depending on discharge depth
- Float: 54.0V (13.5V per 12V equivalent)
- Equalize: 59.2V (14.8V per 12V) — monthly for flooded, optional for OPzV
- Temperature compensation: -4mV/cell/C from 25C baseline
CHISEN Battery — 8 factories, 70M kVAh/year. OPzV/OPzS 100-3000Ah. Tel: +86 131 2666 8999 | jack@chisen.cn | www.chisen.cn