Voltage boost from panels to inverter.

[UnDa_KuVa]

Hi everyone.

I have recently installed 2 x 435 Watt Trina solar panels on my self converted motorhome, with a micro inverter charger.

The inverter charger I bought states that it needs 90v minimum vac to 450v max vac to function. With the two panels I bought I'm averaging about 97vac, to my surprise it will not charge my battery bank. I contacted the manufacturer in China and they suggest that I need to have a minimum of 130 volts to make it stable and work whatever that means.

The problem is I don't have any more room for any panels, would anyone have a suggestion how I can potentially boost my panels to get that extra vcd. To be clear the panels are in series to create 24 volts I will post pictures and specifications.

Thanks

(Edit) :

As pointed out by others, The mppt tracking does say 30vdc - 400vdc wich I am well above.

I initially thought I need 90v min but that is "vac" on the stats for usage etc. Not applicable towards the issue.

Mr so called expert who commented earlier being a condescending A-hole didn't even pick that up tsk tsk!

 

[time2roll]

Need another panel or a different inverter. Can you get a rooftop picture and post it up?

 

[UnDa_KuVa]

Need another panel or a different inverter. Can you get a rooftop picture and post it up?

I can't get a pic at this time, but it would be pointless as I don't have room for another panel.

 

[Bop]

.

 

[upnorthandpersonal]

@Bop While you are correct, please phrase it differently. OP is new to the forum after all.

 

[DIYrich]

- fit an external MPPT charge controller with a more suitable voltage range... and use it to charge the battery bank and use the inverter purely as an inverter and ignore its inbuilt charge controller, use it with your existing panels with their 77.2v Vmp rating , you will need either a 100v PVmax, or a 150v PV max rated one...

This

However, according to picture 2, your MPPT has a 30-400v range, so the panels should work in series (77v) or parallel (36.8v).

 

[HarryN]

A possible option would be to remove the 2 existing panels and purchase some roughly 200 watt, 24 volt panels that have a Vmp in the 30 - 40 volts range. Wire them in series to hit the target voltage range needed.

 

[Hedges]

That 90V figure is AC voltage in.
The MPPT minimum is 30V, max 400V.

Ain't nothing wrong with panel specs.
Does inverter display the PV voltage it sees? Can you measure it?
Maybe there is an open circuit. Or maybe they are connected reverse polarity.

 

[UnDa_KuVa]

That 90V figure is AC voltage in.
The MPPT minimum is 30V, max 400V.

Ain't nothing wrong with panel specs.
Does inverter display the PV voltage it sees? Can you measure it?
Maybe there is an open circuit. Or maybe they are connected reverse polarity.

Hi Hedges.

Yes it displays 95-97 Volts but no wattage coming in.

When I questioned the manufacturer originally they said 2 panels was enough. Now that I have complained about no power coming in they have said my voltage needs to be 130+ to be "Stable".

 

[UnDa_KuVa]

Hi Hedges.

Yes it displays 95-97 Volts but no wattage coming in.

When I questioned the manufacturer originally they said 2 panels was enough. Now that I have complained about no power coming in they have said my voltage needs to be 130+ to be "Stable".

 

[Hedges]

That's not what the data sheet says. MPPT operating range 30 to 400V
Surprise, surprise, surprise!

You could buy from someone else who's specs are correct. Or a separate SCC. Or different panels as already suggested.

Is yours 12V or 24V battery?
If 24V, PV panels in parallel could work with PWM SCC.
If 12V battery, MPPT needed whether panels are series or parallel.

 

[UnDa_KuVa]

That's not what the data sheet says. MPPT operating range 30 to 400V
Surprise, surprise, surprise!

You could buy from someone else who's specs are correct. Or a separate SCC. Or different panels as already suggested.

Is yours 12V or 24V battery?
If 24V, PV panels in parallel could work with PWM SCC.
If 12V battery, MPPT needed whether panels are series or parallel.

Exactly!

I'm just going to buy another inverter and resell my current one. As I dont have enough room for more panels and my funds are a little tight to buy more panels as I am self building my own motorhome and it's a money pit.

24v 8 cells with a Daly 150A bms

 

[UnDa_KuVa]

Update:

I purchased a seperate Mppt (Vevor 24v 40a) hooked it up to the batteries and got it on the correct settings according to the manual. Purple light indicates 24v lithium iron phosphate batteries, (Solid Green Light) indicates batteries full which they aren't and Solid Red Light (PV) is indicating Bulk charging.

I've tweaked some settings on my Daly Bms from the standard factory settings, but can't seem to get it to charge the batteries.

I've added a bunch of screen shots for anyone to look at.

I appreciate any help.

 

[UnDa_KuVa]

Attached

 

[UnDa_KuVa]

Attached

 

[UnDa_KuVa]

Update 2.0

An example of 1 of my issues is the Sum Volt is way too high. I have set it to 28.2v but it has reached 29.1. the BMS won't charge the batteries either. Then I have the Maximum cell voltage set to 3.6v but it has gone to 3.744v at 1 point. I had to switch off the solar system to stop any damages.