Battery Charging Float or Three Stage ? Forums

dipsticks

[align=justify]Our AS Duetto has a CT Leisure Battery Charger from Plug-in-Power Systems model CTSAN/18A. It is called a 3 stage battery charger and has the option of running as a 3 stage or float charger.

The instructions state "On all models there is a selectable 3-stage / float charge feature. This allows a battery to be more fully and more quickly charged when the 3-stage mode is used." "To select the required mode slide the selector switch to the 'Float' or '3-stage position." "The output voltages and currents will then be set".

Float charge position constant voltage at 13.6v, variable current.

3-stage position *bulk charge constant current 18a variable voltage.*absorption mode constant volts at 14.5v,variable current.*float mode constant volts at 13.6v variable current.

Having read that and the previous posts on this subject I thought it best to use float during lay up and 3-stage during the season in use, however the instructions make this statement "Once set the switch should not be adjusted after installation. The factory default setting is 'float charge'"

This is what confuses me it was delivered in float position and has been used thus, does it have a memory ? has it set itself up for float only now ? any info or reccommendation gratefully received.

(Plug-in-systems do'nt make themselves very easy to speak to)

Thanks

hilldweller

I'd take a guess it is to stop people wagging the switch up and down.

If it was doing it's 18A bulk charge and you flick it to float it might screw up the sequencing.

If I'm right, disconnecting the 240V and 12V then flicking the switch would be safe and probably just powering down the 240V then flicking the switch would also work.

dipsticks

Thank you for that its a good point not to switch under load.

I studied further some instructions that said the absorption mode constant volts at 14.5v may be too high to directly power some 12v circuits.

What is the normal charge voltage from a vehicle alternator ?

I can't tell exactly from the voltmeter on my car. Does anyone know if 14.5v is likely to damage anything on a normal motorhome 12v circuit.?

Thank you

hilldweller

CliveMott

The alternator output voltage will be typically 14.0 volts, in the range 13.8 to 14.2 volts. Any more and it will on a long run cause your battery to excessively gas. Any less and it will not achieve a reasonable charge.

The 3 stage charger will charge a battery quicker and more fully but you need to be aware that during the second phase of charging the voltage can go sufficiently in excess of 14 volts (14.5 quoted above) and this voltage will be maintained until the charging current has fallen to a very low level. This is how the charger determines that the battery is fully charged. Then the charger output voltage will fall to a maintaining or "float" voltage around 13.6 volts. When this works it works well, but some batteries after a few years use get a bit leaky so that the charge current does not fall to the very low level required by the charger to denote its charged. So they gas and gas and gas! Also 14.5 volts can be a bit much for some bits of electronic kit to contend with.
If you are sure that the battery is in good order then use 3 stage.
If you have any doubts then the constant float charge will never cause the battery to excessively gas.

C.

dipsticks

rumik

[quote="dipsticks] ...Having read that and the previous posts on this subject I thought it best to use float during lay up and 3-stage during the season in use, however the instructions make this statement "Once set the switch should not be adjusted after installation. The factory default setting is 'float charge'"

[/quote]

My Orian Zeta uses the same charger and using a mirror-on-a-stick, a piece of string and a headlamp torch (the charger is under the wardrobe floor) I have deduced that it is set to "Float" mode on the sliding switch. The LED is showing green. This is how it was built into the van and judging from the charger's location/orientation it cannot be altered easily.

dipsticks

[/quote]

My Orian Zeta uses the same charger and using a mirror-on-a-stick, a piece of string and a headlamp torch (the charger is under the wardrobe floor) I have deduced that it is set to "Float" mode on the sliding switch. The LED is showing green. This is how it was built into the van and judging from the charger's location/orientation it cannot be altered easily.[/quote]

The green LED indicates float mode. My instructions state this is the default setting from the factory. I suspect the van builders just take it out of the box and fit it, job done.

I need a mirror also but in my van I can easily re-site the charger in order to see the LED and to slide the switch when I want to.
The Led changes colour automatically when 3 stage is selected:-red-bulk charging,yellow-absorption charging,green-float charging.

I certainly think it needs checking with the base vehicle maker and the converter before altering the setting due to the higher voltage 14.5v during absorption charge. As it says in the instructions and also Clive mentioned 14.5v may be too high for some electronic circuitry.

I had a struggle to get the instructions I can e-mail them if you wish Rumik.

rumik