Vmp or voc for series array

nschizzano

Do I add up VMP or VOC for stringing a 400w array in Series?

I have a 135v - 450v window for the jackery explorer 5000. Jackery is confident if it goes over 450 in the cold, the unit will safetely manage the situation, be it regulate voltage  or cut off. 

I have 13 Solar Panels, I payed 100 dollars each. They are new Axitech. They were intended to be 400w each. But when I installed the last 6 from my stack, the panels appeared slightly different and turns out some were 440w. 

Volts and amps all seem very close. Close enough to my knowledge. 

Turns out they are all Bifacial too so thought that may be an added benefit. 

I am not sure what numbers to add up. And if i can saftely use all 13. 

I am in minneosta. If it gets too cold the jackery should safely cut off when the voltage goes over 450. 

I have always added up VOC, the feller i got the panels from was a solar installer for 5 years and he said to add up VMP. 

When I google search, it tells me to add up the VOC.


Here is the data:

Anyways I have: 6 Axitec AC-440TGB/108BB and 7 Axitec AC-400MBT/108V

Here is a Google overview and I beleive its accurate: 

A single series string results in a total open-circuit voltage (Voc) of 498.47 V and a maximum power voltage (Vmp) of 410.12 V under standard testing conditions.Total Array Voltage CalculationIn a series circuit, voltage is additive, but the current is restricted to the lowest-rated panel.Axitec AC-440TGB/108BB: Voc = 39.83 V | Vmp = 32.24 VAxitec AC-400MBT/108V: Voc = 37.07 V | Vmp = 31.01 VOpen-Circuit Voltage Calculation (Voc):$6 × 39.83 V + 7 × 37.07 V = 238.98 V + 259.49 V = 498.47 VMaximum Power Voltage Calculation (Vmp):$6 × 32.24 V + 7 × 31.01 V = 193.44 V + 216.07 V = 410.12 V


Additionally my max Amp the jackery can handle is 15A, and these panels are rated below that around 13-14

seems like with the 440w panels it will still work in the mix. 

They may produce more around 410-415 and thats okay, along with all being bifacial i should get a little extra juice. 

Hope it works.