The choices that trip people up the most — which charge controller, which battery, which system type, which panel — laid out in clear tables so you can see the trade-offs at a glance.
Both protect your battery; the difference is how much solar energy they capture and what array voltage they can handle.
| Feature | MPPT | PWM |
|---|---|---|
| How it works | DC-to-DC converter; runs the panel at its best voltage | Connects the panel almost directly to the battery |
| Energy captured | Highest — about 15–30% more | Lower; wastes panel voltage above the battery |
| Best array voltage | Array voltage much higher than the battery | Panel voltage close to the battery |
| Cold-weather gain | Large (cold means higher voltage to convert) | Little |
| Cost | Higher | Lower |
| Best for | Larger systems, series arrays, off-grid | Small, simple 12 V systems on a budget |
Learn more: MPPT vs PWM guide · Charge controller calculator
Lead-acid is cheaper to buy; lithium is usually cheaper per usable kilowatt-hour over its life. Here's why.
| Feature | Lithium (LiFePO4) | Lead-acid |
|---|---|---|
| Usable depth of discharge | 80–90% | ~50% |
| Cycle life | 3,000–6,000+ cycles | 500–1,200 cycles |
| Round-trip efficiency | ~95–98% | ~80–85% |
| Upfront cost | High | Low |
| Cost per usable kWh over life | Lower | Higher |
| Weight & size | Light and compact | Heavy and bulky |
| Maintenance | None | Watering (flooded types) |
| Best for | Daily cycling, off-grid, solar storage | Occasional backup, tight budgets |
Related: Battery calculator · Battery Ah to kWh converter
The system type decides whether you have a battery, whether you keep power in an outage, and how much it costs.
| Feature | Grid-tied | Off-grid | Hybrid |
|---|---|---|---|
| Battery | None | Required | Yes |
| Grid connection | Yes | None | Yes |
| Power during outage | No (shuts off) | Yes (sole source) | Yes (backup) |
| Upfront cost | Lowest | Highest | High |
| Complexity | Simple | Complex | Moderate |
| Best for | Lowest bills where the grid is reliable | Sites with no grid access | Backup power plus bill savings |
Learn more: Grid-tied vs off-grid vs hybrid guide · Off-grid system wizard
The three main panel technologies trade efficiency, cost, and how much space they need.
| Feature | Monocrystalline | Polycrystalline | Thin-film |
|---|---|---|---|
| Efficiency | Highest (~19–22%) | Medium (~15–17%) | Lowest (~10–13%) |
| Cost | Higher | Medium | Low per watt |
| Roof space needed | Least | More | Most |
| Heat & low-light | Good in heat | Average | Best in heat and partial shade |
| Appearance | Black, uniform | Blue, speckled | Thin, often flexible |
| Best for | Limited roof space | Budget builds with room | Large areas, curved or portable surfaces |
Related: Panel calculator · Roof area to system size · Temperature derating