Ok so... I have a epever MPPT controller and a Sargent Campervan ECB. My question is...if I connect the controller between the batteries and the controller what happens when I am plugged in at a campsite or when the alternator is producing power? Will it flow in reverse back through the controller?
Load reversal
- Thread starter Dm5
- Start date
Welcome to the forum.
I'm not familiar with that unit or any deeper implications, but charge controllers are continuously attached to batteries, and they don't drain them any faster than the current they need from them.
The only potential issue is if charging sources somehow significantly exceeded the charge controller's rated voltage, i.e., subject a 12/24V SCC to something like 40V - that would probably destroy it because the voltage would overwhelm the circuitry protecting the SCC.
If a super high voltage situation happens, you're also likely dealing with destroyed batteries and any other attached electronics.
Thank you. I think this won’t be an issue. The whole setup is 12v and the controller is 20A which is the maximum fuse in the ecb.
My question is really about what if power is coming the opposite direction ie. from the ecb to the load terminals on the MPPT controller and out to the batteries for example if on a hook up...will power flow in that direction? I think it will but wondered if there are worries it won’t.
Again, the MPPT will only pull the current it needs from a circuit. The only danger is if the circuit powering the MPPT voltage exceeds the MPPT's voltage limits.
Stated another way, you could push 10,000A into your 12V battery with the MPPT attached, and the MPPT would only pull the milliAmps it needs to power itself.
Charging from multiple sources
One can have as many independent charging sources running concurrently as they like provided they are programmed properly for the voltage of one's battery bank. Examples (some or all at once, even multiples of a single type, different brands, etc.): Solar PV via MPPT Solar PV via PWM AC-DC...
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mikefitz
Solar Wizard
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mikefitz
Solar Wizard
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I recommend you dont use the load outputs of the solar controller. Connect the controller battery connections direct to the leisure, service battery, with a 10A fuse at the battery in the positive cable, use 4mm2 or 6mm2 cable. Connect the solar panel to the solar inputs, leave the load terminals unused. When commissioning the system connect battery first , panels second, disconnect in reverse order.
The solar controller is best regarded as a separate system to the Sargent unit, just looking after the leisure battery. The Sargent unit will still display battery voltage correctly.
Your diagram shows a 'relay' between the Sargent and the starter battery, the Sargent usually has the 'combining relay' within the unit.
Mike
The solar controller is best regarded as a separate system to the Sargent unit, just looking after the leisure battery. The Sargent unit will still display battery voltage correctly.
Your diagram shows a 'relay' between the Sargent and the starter battery, the Sargent usually has the 'combining relay' within the unit.
Mike
Hi Mike, thanks for the advice. There is a combining relay in the unit. Not sure what the nagres relay is for. The issue I have with the camper is that accessing the battery through the floor is very difficult.
What would be the issue of using the load?
Also could I run it like a spur? I.e in diagram below.
What would be the issue of using the load?
Also could I run it like a spur? I.e in diagram below.
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mikefitz
Solar Wizard
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You could connect to the leisure battery at any point. The connections to the EC200 are shown below,
A and D are leisure positive, C and F are negative, common to all batteries and van metalwork.
If your motor home is part of the Swift group they use brown for leisure positive and black for negative.
You should have battery access for maintenance or replacement.
If your van is UK built, using the Sargent unit suggests that, cable sizes and electrical equipment is often inadequate and is not easy to update and add additional equipment .
The load terminals of low power solar controllers are primarily designed to control remote installations like lighting or traffic signs. They are controlled with electronic one way switches that may not be compatible with the Sargent AC charging system.
Mike
A and D are leisure positive, C and F are negative, common to all batteries and van metalwork.
If your motor home is part of the Swift group they use brown for leisure positive and black for negative.
You should have battery access for maintenance or replacement.
If your van is UK built, using the Sargent unit suggests that, cable sizes and electrical equipment is often inadequate and is not easy to update and add additional equipment .
The load terminals of low power solar controllers are primarily designed to control remote installations like lighting or traffic signs. They are controlled with electronic one way switches that may not be compatible with the Sargent AC charging system.
Mike
Cheers Mike, yeah it’s a VW T5 so batteries can be replaced but they are in cages under the van and therefore cables need to go through the floor. So are you saying I can just take a ‘spur’ like I suggested off the leisure cables. It will top up the leisure batt and the Sargent will still get power. BTW MPPT controller is an epever AN 2210 which I thought was a decent one
