# RV and vandwellers wiki

### Site Tools

12v:sg_troubleshooting

# common power station issues

## TL;DR

• Power Stations (PS hereafter) generally perform to spec.
• most “problems” result from unrealistic expectations, which result from

## must I use the PS brand's proprietary solar panels?

No, you can use any panel that meets spec. Consult the power station's solar ("PV") input specs and buy panel[s] whose output specs are within the PS' stated limits. For the purposes of this section we will use these actual specs for reference:

`12v-45v, 10A`

In this case

• panel1) Vmp must be ≥12.0v
• panel Voc must be ≤45.0v
• the controller will allow ≤10A of input current2)

Sometimes the spec will also state the voltage range where the panels can be run at maximum power:

`MPPT range 15v-38v`

This tells us that Vmp can be anywhere from 15v to 38v. Outside that range (but within the absolute limits above) the panels will make something but not maximum power.

### maxxing out the solar input

Power station solar input docs give a Max Wattage spec with a voltage range and usually a current limit. In the case of our example that limit is `10A`.

Watts = Volts x Amps, so the Vmp of our panel3) will dictate what we can get at that 10A limit:

• 18Vmp x 10A = 180w
• 36Vmp x 10A = 360w
• 40Vmp x 10A = 400w

Sometimes no current limit is stated and we have to back into it. In our case the 500w will be attainable at at 45v, suggesting the current limit is 11.11A (500w / 45v). Remember the panel's Voc cannot exceed 45v so we cannot really run a 45Vmp panel.4)

## my PS only has one DC outlet

you can run the DC output to a bus or fuse box to split the connection. The total current must be within the PS' DC ouput limit; see below.

## the DC outlets don't have enough power to run my DC loads

There is no easy/cheap way around this. Buy a PS that has sufficient specs to meet your needs.

## my PS doesn't charge well from the 12v ciggy port

1. bad connection - 12v ciggy ports are substandard even on their best behavior.
2. the chassis voltage is varying, so the 12v volt outlet voltage is varying, so the charge rate is varying (I=V/R)
3. the power station is throttling charge rate
and if theres a way to have it always charge at 100w?

That depends on the cause, the power station, and one's ability/willingness to DIY a solution. And it can't be always, just more of the time.5)

### if the problem is the connection

… then fix the connection. Clean/adjust/replace as needed. Anderson PowerPoles are a common upgrade.

### if the problem is ciggy port voltage

If the wall charger output is 100w you could even run a cheap inverter from the ciggy port and plug the wall charger into that. It would be inefficient but we don't really care because the numbers are small and alternator output relative massive. This approach would work because the wall charger's output is usually at the higher end of the SG's DC input voltage limit.

If the wall charger >100w6) you could get more consistent charging by boosting/regulating voltage up as described above. So if the wall charger runs at 15v one might boost the outlet's voltage to 15v.

If it's a larger PS that can accept 100s of watts it might be easier to run a semi-DIY relay/inverter setup.

1)
or panel string, if wired in series
2)
although the inner workings of PS are often undocumented, generally speaking MPPT controllers will drive Vpanel > Vmp toward Voc to limit current to a particular spec
3)
or panel string if in series
4)
Voc is always > Vmp, typically by ~20%
5)
the nature of Absorption requires current to taper to avoid overshooting the voltage setpoint
6)
>100w wall charger + inverter losses could exceed the ciggy port's output limit, typically 10A.