OutBack FLEXmax 80
#29 in MPPT solarFull review
For off-grid homes and cabins on 24 or 48 V, especially those built around OutBack inverters. A proven 80 A controller at a fair price.
NAZ Solar Electric $527.99$527.99
The OutBack FLEXmax 80 is the better charge controller overall, rated 3.6 to 3.1. The OutBack FLEXmax 80 leads on value. The OutBack FLEXmax 100 AFCI wins on efficiency. The OutBack FLEXmax 80 costs $966.67 less ($527.99 vs $1,494.66).
OutBack FLEXmax 100 AFCI
#39 in MPPT solarFull review
For large 48 V off-grid or backup systems built around OutBack inverters, where 300 V strings and built-in arc-fault protection simplify the install.
NAZ Solar Electric $1,494.66$1,494.66
Prices were last checked October 24, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the OutBack FLEXmax 80 for value ($6.60 per amp of charge current vs $14.95 per amp of charge current).
- Choose the OutBack FLEXmax 100 AFCI for efficiency (98.8% peak efficiency (maker rating) vs 98.4% peak efficiency (maker rating)).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every MPPT solar charge controller; a clear win is highlighted. How we rank explains each one.
| Factor weight | OutBack FLEXmax 80 | OutBack FLEXmax 100 AFCI |
|---|---|---|
| Overall rating | 3.6/5 | 3.1/5 |
| Value 35% | 45 $6.60 per amp of charge current | 0 $14.95 per amp of charge current |
| Features 25% | 30 temperature sensor, 150 V PV input; no Bluetooth | 30 temperature sensor, 300 V PV input; no Bluetooth |
| Efficiency 20% | 86 98.4% peak efficiency (maker rating) | 95 98.8% peak efficiency (maker rating) |
| Warranty 20% | 100 5-year warranty | 100 5-year warranty |
Specifications
| OutBack FLEXmax 80 | OutBack FLEXmax 100 AFCI | |
|---|---|---|
| Charging | ||
| Type | MPPT solar charge controller | MPPT solar charge controller |
| Charge current | 80 A | 100 A |
| Battery voltage | 12/24/36/48/60 V | 24/36/48 V |
| Custom profile | Yes | Yes |
| Temperature sensor | Optional extra | Optional extra |
| Peak efficiency | 98.4% | 98.8% |
| Standby draw | 83 mA | 104 mA |
| Inputs | ||
| Max PV voltage (Voc) | 150 V | 300 V |
| Max PV power (12 V) | 1,000 W | - |
| Max PV power (48 V) | 4,000 W | 7,000 W |
| Monitoring and build | ||
| Bluetooth | No | No |
| Display | Yes | No |
| Load output | No | No |
| Cooling | fan (active cooling) | fan |
| Water resistance | Indoor Type 1 | IP54 (Type 3R) |
| Dimensions | 41.3 x 14.6 x 11.4 cm (16.25 x 5.75 x 4.5 in) | 58.4 x 22.4 x 15.2 cm (23 x 8.8 x 6 in) |
| Weight | 12.2 lb | 16 lb |
| Warranty | 5 years | 5 years |
| Released | 2008-07 | - |