Inverter/Charger problem

[johndoe]

Have two battery banks with one Inverter/Charger.
Battery bank one is start battery. one 12 volt cranking battery.
Battery two is two 6v 260AH deep cycle for house.

The inverter/charger should be able to charge both banks at the same time. I have off-1-all-2 battery switch...

Switch is in All position when hooked to shore power... then to 1 for starting... 2 when on hook...etc..

Seems pretty simple, but battery one is not holding its charge from the Inverter..

Are these two batteries incompatible? what type of batteries should be used?

 

[Boatist]

Re: Inverter/Charger problem

I guess I not fully understanding your question.

An inverter runs on 12 Volts DC to produce 110 Volts AC and any battery it run off of will need to supply a lot of power.

If you mean battery 1 and 2 are charged from a shore charger with your switch in the all position and battery 1 is run down when you go to use it then I would make some checks.

When charged from shore power with your switch in the all position take a volt meter and messure the voltage at battery one. Very inportant to mesure the battery from the Battery post them selfs not from the cable attached. While being charged the battery should be between 13.8 Volts and 14.4 volts. charged that way battery 2 should be the same. If it has that voltage on it and is stilled not charging up then check the water levels if it is not a sealed battery. If the water level is good and and voltage is 13.8 volts or more on the charger then the battery is likely bad. Turn the charger off and the switch to off and check battery voltage again. It should 12.6 Volts or higher at around 70 degrees. Set switch to 1 and turn on navigation lights and messure again. With this light load the battery should still be near 12.6 volts. If it is 10.5 volts then you have a bad cell and battery needs replaced.

 

[Dunaruna]

Re: Inverter/Charger problem

[colour=blue]I think he is talking about an inverter & charger in the one unit. They are available but not very common.

 

[I/O WALDO]

Re: Inverter/Charger problem

Sounds like a bad #1 battery. The charging absorption rate of the 6volts is slower than the 12v and if anything should overcharge it.Does your inverter have a temp.sensor connected to it to monitor the batt.temp?If you always leave the inverter /charger on when away the sensor should be on the 12v start battery.Like Boatist said,ck.the charge volts at #1.

 

[johndoe]

Re: Inverter/Charger problem

Yes this is a charger/inverter combo unit... magnum MS series 2kW inverter...

I do not have the battery temp sensor option installed at this time...

I made all the voltage checks and all seemed fine, but when I put switch to battery one, and turn on light load appliances, (lights head etc...) the battery one goes dead rapidly... (lights go dim and co2 detectors begin beeping low power) rapidly... within 2 minutes.

I removed battery one from boat and metered 8 volts...
not good!

replaced with same type of battery, (used one I had at home on maintenance charger) and have not checked it since it charged over night...

I seem to remember reading that the batteries on this type of set up MUST be of the same type...? anyone have more information on this..

 

[I/O WALDO]

Re: Inverter/Charger problem

On an inverter bank the batterys are supposed to be the same size, type and age.Different types/size batts have different charging profiles.With a high amp charger like yours (100amp??) and diff.size batts.,you can cook one batt while leaving the others low.Inverters sometime have a low amp charge output separate from the main house output that is for the start batt.If so,the start batt can be different type/size.

 

[johndoe]

Re: Inverter/Charger problem

So what about hooking up a separate smaller charger just to the start battery... would I have to isolate it from the larger charger, or just leave the switch on 2....

some kind of special wiring for this application?

 

[drewpster]

Re: Inverter/Charger problem

If your 1-2-both switch is wired right your batteries should already be isolated. Simply turn the switch to the off position when charging the batts with two chargers and the batteries should be separated from the electrics and from each other.

 

[drewpster]

Re: Inverter/Charger problem

I forgot to mention I am assuming you have the inverter connected to the house battery. If it is connected to the common post of the battery switch it won't charge with the switch in the off position. If you go with using two chargers, move the inverter lead to the pos. post on the house battery.

 

[I/O WALDO]

Re: Inverter/Charger problem

I read up on your inverter and sea it has only one d.c. connection and 100 amps charging output.(connected to the house bank,knott through the batt.switch.)I wonder if you could hook an isolator input to the house bank and one of the outputs to the start battery's + term.This would/should treat the inverter as a charging source and also cut the charge volts/current back on the start batt. to an acceptable level?? Any opinions??

 

[drewpster]

Re: Inverter/Charger problem

Sounds a little like your trying to use an isolator as a resistor.
As I understand it batteries will only accept the charge they need. (to a point) so if you have one deeply discharged battery and one fresh one in a single bank it should not matter what the charger is putting out. The dead battery will take what it needs and the fresh one will do the same.

 

[I/O WALDO]

Re: Inverter/Charger problem

I run a Freedom 1500 inv/charger with 3, 27size 12v deeps paralled on the house and one matching 27 deep on the start.There is an on/off switch between the start and house. Batterys are 3 years old and all check out fine now.Boat is in a slip and the 1500 is always on with all the batts charging.Temp.sensor is on the start batt,never cooked any batterys.(Turn batt sw.off while on hook.) If you have a bank,they all should drop together. If all the batts are the same,all is fine,if one is different,Could be trouble.I was suggesting the isolator for isolation also.