Series vs Parallel: Wiring Solar Panels to a Power Station
By Hicham M. · Updated October 11, 2026
Connecting more than one panel? How you wire them decides whether your power station charges at full speed, wastes power, or gets damaged. It comes down to the solar input's voltage window.
The numbers on your panel's label
- Voc (open-circuit voltage): the highest voltage the panel produces, with nothing connected. This is the one that can damage an input.
- Vmp (voltage at max power): the voltage while it's charging.
- Imp (current at max power): the current while charging.
Your power station's manual lists its solar input range (for example 11–60 V), a maximum current and a maximum wattage.
Series: voltages add up
Connect the positive of one panel to the negative of the next. Voltage adds, current stays the same. Series is great for inputs with a wide or high voltage range, and it loses less power over long cable runs.
The limit is the maximum voltage. Using EcoFlow DELTA 3 Plus (solar input 11–60 V) with typical 200 W panels (Voc 24.3 V):
- 2 in series: Voc = 48.6 V, inside the limit. About 300 W of charging in good sun.
- 3 in series: Voc = 72.9 V, over the 60 V maximum. Don't do this.
Parallel: currents add up
Connect positive to positive and negative to negative, usually with a branch connector. Current adds, voltage stays the same. Parallel keeps the voltage low, but current can hit the input's limit: 2 panels give 19.6 A, and this model accepts up to 15 A, so some power is wasted. While charging, the station only draws the current it can handle, but makers still set a limit on the array's short-circuit current (Isc, also on the panel label). Add up the panels' Isc and keep it within the input's rating.
Cold weather raises voltage
Panel voltage rises as temperature drops, and the label value is measured at 25 °C (77 °F). How much it rises is on the panel’s datasheet as a temperature coefficient: EcoFlow’s 125 W bifacial panel, for example, loses about 0.25% of Voc per °C, so on a −10 °C (14 °F) morning its Voc is about 9% above the label.
Electricians use a cautious version of the same idea. The National Electrical Code’s table 690.7 multiplies Voc by 1.10 near freezing, 1.14 at −6 to −10 °C and 1.25 at −36 to −40 °C. With the 1.14 factor, the two panels above would reach about 55.4 V, still inside the 60 V limit. If your series Voc is within about 10–15% of the maximum, drop a panel or switch to parallel.
The manufacturers are blunt about it. EcoFlow’s manuals for the DELTA 3 1500 and DELTA 3 Max Plus say to keep the array’s open-circuit voltage within 60 V and its total short-circuit current within the input’s limit (15 A and 18 A respectively) “to avoid product damage”.
Other rules of thumb
- Don't mix different panel models in series. The weakest panel's current limits the whole string.
- If your station has two solar inputs, two separate arrays often beat one big one.
- Some inputs behave differently at low voltage. Jackery’s Explorer 1000 v2 accepts up to 8 A at 12–16 V but 10.5 A at 16–60 V, so a single small panel may charge more slowly than its wattage suggests.
- Check connectors: most panels use MC4, while stations use XT60, Anderson or 8 mm ports. Use the adapter your station's maker specifies.
Check your setup with the solar charging calculator. It flags over-voltage, under-voltage and current limits for your model.
Sources
- santansolar.com/wp-content/uploads/EcoFlow-125W-Bifacial-Modular-Solar-P…
- mikeholt.com/instructor2/img/product/pdf/14SOLB-1229-sample.pdf
- media.hornbach.lu/hb/ownersmanual/as.112866645.pdf
- images.thdstatic.com/catalog/pdfImages/8c/8c6c1de9-c662-482a-9fdb-55e51223121…
- jackery.com/products/jackery-explorer-1000-v2