Charging Multiple Battery Banks

[noelex 77]

Originally Posted by nmit5903

Digressing - found to my amazement today that my two 80W solar panels are actually drawing current (3.7A each) when in the shade and that neither is fitted with a diode to stop that - effect being the array is only ever working at or near half capacity as one panel or other is generally shaded.

They should not be drawing anything like this without a blocking diode.
Something else is wrong, or you are not measuring what you think you are measuring.

[nmit5903]

.........according to Mr "Sparky"and he's been pretty on the ball so far. Disconnected them both from the circuit and draw is zero which would say there is no leakage elsewhere.

Connect each one, independently - current between 5 and -3.6.

Solar specialist here tells me that can happen if no diode fitted. Didnt ask why else the diode is fitted?

Suppose we will see later this week when diodes and new regulator fitted. If it works and battery leakage/current draw is eliminated I will be happy.

[nmit5903]

All done and working well. Solar charging well with diodes. It seems the panels can indeed soak up power as nothing else tampered with.

[goboatingnow]

a PV panel is rather like a PN diode. if it gets forward biased , like in low light, current flows into it.

Dave

[Jeff Millar]

OK, I need your experience and help please. I will have a 12 volt diesel engine start battery and a 12 volt battery the same size at the windlass. Both of these will be charged bt the engine alternator. And a seperate small battery charger run from a Honda 2000 i , gasoline driven generaror if ever needed as emergency charging.

I will have ONE 12 volt, 1000 AH House Bank Battery ( ALL BATTERIES SAME SIZED ) Charged from a Battery Charger supplied with 120 volts AC from my Northernlights Diesel Generator. And would have Solar Panel ( 132 watt ) and Wind Turbine to feed into the House Bank Battery , with voltage regulation.

If my diesel generator were out of commission I would have the Honda available to put some charge ( 70 amps dc ) into the House Bank.

Is this where the combiner becomes usefull. Assumption that the engine alternator would have charged the Start BATTERY and the Windlass Battery would now automatically switch over and charge the House Bank Battery. Engine running.

Please fill in the blanks e.g. Alternator voltage regulator settings.

My battery for the House Bank will be wet cell or AGM. LEANING TOWARDS WET CELL.

Your expert guidance would be greatly appreciated.

Thank you in advance for any help you may offer.

Jeff

[colemj]

A single 1000Ahr house battery? Maybe I read wrong and you mean a single bank of multiple batteries?

Yes, this is where combiners are useful. Wire all charging sources to charge the house bank and connect combiners between the house and start and house and windlass batteries.

All charging source regulator voltages and times should be set as per battery manufacturer recommendation (they will be different depending on your battery choice).

Mark

[Jeff Millar]

Experience and expert help please. Hope this request is beating a dead horse.
1- Have 4 existing 12 volt lead acid batteries, used for starting the diesel engine and using the windlass when the engine is running. Re-charging these Batteries is from the existing alternator with new smart voltage regulator.
2- New House Battery Bank consisting of 2 - 300 AH Lithium - Ion 12 Volt Batteries connected in parallel, re - charged from the generator by new Battery Charger , customized for the Lithiun - Ion Batteries. Simple.
But if running under the engine with the starting battery fully charged, presently no way to use this alternator to charge the House Bank Battery.

a - Seems the only options available would be to have a second alternator with voltage regulator to supply the House Bank.
b - Have only one Battery ( Lithium - Ion ) that could be re-charged from the engine driven alternator or the Generator via the Battery Charger which is customised to charge the Lithium battery.

This may be the theory. But out there in the real World what would you experienced yachties recommend.

Thank you

[Jeff Millar]

See Sterling USA for new Voltage Regulators, Alternator modified amps increased output. Might be big help.