Just purchased a campervan with solar setup

[MisterE]

Hi all,

So I have just inherited a solar installation attached to our camper van. When we purchased it the previous owner had removed the batteries as they had apparently reached end of life. There are also currently some issues with the installed flexible solar panels due to corrosion so, in the interim I chose to charge the new batteries with a standard mains batter charger. For some reason even though the charger is saying the the batteries are fully charged the meter connected to my EPSolar Tracer 1210RN MPPT controller is only reading 75% full. As this is my first foray into solar I'd like to know whether that is to be expected.

Any advice would be appreciated.


regards,
Michael.

[SunEagle]

Hello MisterE and welcome to Solar Panel Talk

The problem with a standard battery charger is that their SOC measuring device is crude and not always accurate. It doesn't really matter if your vehicle battery is only 80% full since once the engine cranks the alternator will keep them as full as possible.

MPPT solar charge controllers use a different logic to determine the SOC of a battery and usually have much better programming across the charging stages then an off the shelf car battery charger.

If you can measure the specific gravity of each cell with a quality hydrometer you will get a better idea of the batteries SOC. If the battery is sealed then it makes it a little harder to know exactly what % charge it is.

[NEOH]

There is no such thing as "Standard Mains Charger" - they are all different.
What is the Make & Model of your "Mains" Charger?
Is it three stage charger?
Does it have Bulk Mode, Absorb Mode & Float Mode?
Do you know what the settings are for the various modes?
How is the charger determining that the battery is 100% Charged?

What is the Make, Model and Voltage of your new batteries?
How do you have them connected?
In parallel or in series?

Are the batteries Sealed AGM type or Flooded Lead Acid type?

In addition to measuring the SG ...
Let the batteries rest for 24 hours, with no charger connected and no loads connected.
Now measure the voltage of each battery and reply with the readings.

We need more details.

[MisterE]

Thanks all for your responses. Some more detail as requested.

Mains charger is a Projecta Pro-Charge http://www.supercheapauto.co.nz/Prod...nuFrom=1021637
Apparently 6 stage charging system
Comes with Bulk, absorb, and float modes
Not much in the way of settings available. No idea how it determines that the batteries are 100% charged

I have two Bosch 12v 70ahr flooded lead acid batteries connected in parallel. They are brand new.

I will let the batteries rest this weekend and get back to you with voltages. Unfortunately the only hydrometer I have is for my home made rum. Pretty sure it won't work for batteries

One point to note is that this is (ordinarily) a fully independent solar system. there is no connection to the alternator for charging.

[Raul]

The meter needs resetting . It hasn't seen a full charging cycle by the controler, and maybe is set to a higher voltage to reset, compared to your plug in charger.