MAXIMUM POWER POINT TRACKING REGULATOR FAQS
Q: What is an MPPT?
MPPT stands for Maximum Power Point Tracker and is a specialized converter designed to maintain the PV voltage at the level in which it delivers maximum power to the load or battery. The panel’s nominal output power can only be obtained with the use of an MPPT.
Q: What are the GSL MPPT’s advantages compared to standard solar regulators? 1. Suitable for lower cost non battery type PV since the MPPT can efficiently charge the
batteries from relatively high voltage, say 24V batteries from 40Vmp panels.
2. Less interference and more accurate voltages during absorption and float.
Q: What sorts of loads can I power with the MPPT60-1?
1.The maximum bulk charge current with the MPPT60-1 on a 12V battery and 800W panel is approximately 60A, so you can expect about 200Ah per day which means a 200W load for about 10 hours daily.
2. Following the same reasoning with a 24V 1600W panel the MPPT60-1 will supply a daily load of 400W for about 10 hours.
3. Following the same reasoning with a 48V 3200W panel the MPPT60-1 will supply a daily load of 800W for about 10 hours.
Q: Why are MPPT not more common in standalone solar systems?
Until now and despite their overwhelming advantages MPPTs have not been commonly used in standalone solar systems because of cost. The new GSL MPPT specifically addresses this issue making economic sense in a wide range of solar systems.
Q: What sort of batteries should I use?
1. A deep cycle battery is a must due to the cyclical nature of the solar system with a
recommended battery capacity of at least 180Ah.
2. A larger battery will not only give longer run time during low light but also will be able to avoid available PV power being unstored such as when the battery reaches the float stage.
Q: How do PV temperatures affects charge current?
Temperature increase brings down the PVs maximum power point voltage reducing the
MPPTs current gain available. In principle at 25C it is possible to achieve 30% gain but at 40C, a more realistic average temperature, about 20% is still available.
Q: What happens at low PV currents?
The MPPT will outperform the conventional regulator above 3% of nominal panel power. Below 3%, about 10W in a 400W panel, the MPPT will have a slightly lower output current than a non MPPT.
Q: Is interference possible? and If so what do I do?
GSL’s MPPTs produce far less interference than a conventional solar regulator during
the absorption and float stages, that is during most of its operating time, and its
designed to comply with local and international EMI standards however some
interference is still possible. If interference occurs first try and reorient the aerial or move the sensitive equipment away from the MPPT wires. Ensure the MPPT chassis is grounded.
Grounding a battery terminal may also help and finally you can try adding ferrite clamps.
Input voltage: 15-95V (cell open circuit voltage)
float 13.5V / 27V / 54V
absorption (vented LA batt.) 14.5V / 29V / 58V
absorption (SLA batt.) 14.2V / 28.4V / 56.8V
Output: 60A max (3400W)
No load (Quiescent current): 0.05A
Dimensions: 260 x 145 x 67mm
Connections: 8 gauge 7.7mm2 wire
• LED status indicator
• Thermal protection
• Auto battery voltage detect
• Up to 20% improved panel efficiency
• Suits vented or sealed lead acid batteries
• High efficiency, typically 97%