Advice required for wiring Solar panel MPPT

[RustyRuss]

Hi all you knowledgeable PV bods out there! I’ve bought an EPEVER Duo Racer MPPT charge controller, I have put two additional 120w solar panels on the roof of the MOHO (total of 3 now) and I’m planning to connect up as per wiring diagram from EPEVER. I’m going to connect the panels in parallel to each other with a 10amp diode on each of the +ve leads of the panels before they are joined together with a “three into one” connector. I’m going to connect the EPEVER unit directly to the lithium leisure battery as “Batt 1” and directly to the vehicle starter battery as “Batt 2”. My question is what should I do with the mains charging from the Sargent EC500? Can I leave it alone and when it’s plugged in to the EHU it’ll charge both batteries and the EPEVER will also charge them? Or should I incorporate some switching that switches off the EPEVER when I’m on EHU? The EPEVER diagram shows a “breaker” in the +ve feed from the solar panels, should this just be a simple switch? Or does it need to be a 12-18v DC breaker?
Cast some knowledgeable light please as I don’t want to blow up lots of expensive components! Also advise if I need to buy more stuff!!

Thanks in advance boys n girls!

Russ

 

[eddie]

You really don’t need a 120w solar panel connected to the engine battery, most of the time it will be doing nothing.

I have three 150w panels connected to my leisure batteries (lithium) and a Battery Master (other devices are available ) which trickle charges and maintains the engine battery automatically as and when required

 

[Gaston aires]

Trust Eddie. He da man.
Phil

 

[Tombola]

The ehu and the solar can charge the lithium at the same time.
In reality when you are on ehu you can just turn off the electric charger let the sun do the batteries if you want too.

As per prev, forget hooking one up to the starter battery, no need, just hook all up to the lithium and stick in a battery master

Battery Master install like this

I have 2 16mm cables feeding a b2b charger coming from the cab battery into the leisure/charging area, about 1 metre away. I have ordered a battery master from eddievanbitz (funster code didnt work but hey ho) Am I ok to install the battery master like the pic below? behind the B2B

www.motorhomefun.co.uk

Battery Master Fitter (near Nottingham)

Hello All, I want to get a Battery Master fitted to top up the vehicle battery from the leisure battery. Can anyone recommend a supplier & fitter near to Nottingham? Thanks Stephen

www.motorhomefun.co.uk

 

[eddie]

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[eddie]

And you can buy one on line from the Motorhome Fun shop and save money

 

[Lenny HB]

You really don’t need a 120w solar panel connected to the engine battery, most of the time it will be doing nothing.

I have three 150w panels connected to my leisure batteries (lithium) and a Battery Master (other devices are available ) which trickle charges and maintains the engine battery automatically as and when required

The ehu and the solar can charge the lithium at the same time.
In reality when you are on ehu you can just turn off the electric charger let the sun do the batteries if you want too.

As per prev, forget hooking one up to the starter battery, no need, just hook all up to the lithium and stick in a battery master

The controller he is using the 2nd battery output is a trickle charge for the starter battery. So what he is doing is correct.

 

[Lenny HB]

I’m going to connect the panels in parallel to each other with a 10amp diode on each of the +ve leads of the panels

You don't need the diodes all they will do is give you a voltage drop and reduce the charge rate.

 

[Burgo]

+1 For the battery master. Dead easy to fit and if you have any questions at all they're really helpful people.

 

[Lenny HB]

+1 For the battery master. Dead easy to fit and if you have any questions at all they're really helpful people.

Doesn't need one if you read the OP's post you will see he is using a dual controller.

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[Diabalo]

If you have the Sargent PX-300 charger I don't think it has a lithium charging profile?

 

[eddie]

I suspect that the post was edited as I read that one of the panels was going to be dedicated to the engine battery, hence my post, but that has changed.

 

[RustyRuss]

Hi all! No edits! Maybe I didn’t make myself clear, the EPEVER unit is designed to charge BOTH batteries. The majority of the charge will go to the leisure battery and the EPEVER unit is programmable to specifically charge a leisure lithium battery. The minority of the charge will occasionally go to trickle charge the vehicle battery, and the charging profile for the vehicle is ONLY for a lead acid battery. I am concerned that I will “kill” the original equipment charger that’s fitted as part of the Sargent electrical system if they are both charging the batteries when the Sun’s shining on the PV and the EHU is charging the batteries via the Sargent unit. So can I leave the Sargent kit to it’s own devices and just install the EPEVER unit as per the wiring diagram it came supplied with? Will they “fight” each other or will they both put charge into the batteries? Obviously it won’t be a problem if we’re not connected to the EHU and the PV will do it’s thing via the EPEVER unit, I just want to be sure they’ll be compatible! Will I be best to isolate the PV from the EPEVER unit if I’m on EHU? I hope that makes sense now! Regarding the diodes Lenny, I’m not convinced that the Sargent charger has diodes in it because both of the old batteries (I’ve got a brand new vehicle AND leisure battery) were down to 3volts within 2 weeks of laying up in September and all systems were definitely off so very little likelihood of a phantom drain on the system. I’m even bamboozling myself now!

So in short..... install the EPEVER unit as per installation wiring diagram and ignore Sargent charging kit..... or..... well..... do something else?

Thanks for all your help so far and any that you offer next!

Russ

 

[Lenny HB]

It's normal to have the mains charger an the solar charger both connected to the hab batteries its how every Motorhome with solar is wired. It won't cause any problems.

 

[RustyRuss]

Thanks Lenny!!

Russ

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[Revolvor]

My CTEK 5-stage MPPT solar regulator charges the batteries far more efficiently than the Sargent charger, so when away in the summer, we leave the Sargent charger switched off, even if we are on EHU, and let the 200W solar keep the batteries charged. EHU just used for fridge, kettle and charging e-bike.

 

[RustyRuss]

I’ll give that a try when I’m finally wired up!

Russ