AGM Battery Charger

Ed on Toast

Ed on Toast

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Is a standard battery charger OK to charge 3 x AGM Leisure batteries or do you learned folk recommend a specific one?
 
AGM batteries normally need a higher voltage of 14.7v (2.45v per cell) rather 14.4v (2.40v per cell) to reach full charge. It is also important to have a multi-stage charger so that absorption time is correct and they float at the right voltage (13.8v for AGM).

The charger should be rated at 20% of the 20Hr rate of the batteries. 330Ah would need a 66A charger (no less than 33A and no more than 99A).
 
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If you have an onboard charger, it should have an AGM setting to provide the higher charge as Phil states above.
 
Unlikely that any standard on board charger would cope with 3 batteries {particularly AGM} that have discharged to any great extent - so new 60A mains charger on the shopping list.
Also alternator will will probably benefit from the help of a big B2B charger.
 
Markd said:
Unlikely that any standard on board charger would cope with 3 batteries {particularly AGM} that have discharged to any great extent - so new 60A mains charger on the shopping list.
Also alternator will will probably benefit from the help of a big B2B charger.
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They say about 10amp for a 100ah battery, so 30amp would do as im told dont charge them to fast.
 
My three AGM’s are looked after by 200 watt solar and a Ctek D 250 + Smartpass. The only problem I’ve had so far, and it’s very early days, is with my use of an electric kettle, when parked for more than a few days, with little sun.
It’s all a learning curve. Being locked down doesn’t help.
 
Trotter said:
My three AGM’s are looked after by 200 watt solar and a Ctek D 250 + Smartpass. The only problem I’ve had so far, and it’s very early days, is with my use of an electric kettle, when parked for more than a few days, with little sun.
It’s all a learning curve. Being locked down doesn’t help.
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Worse if your locked up in a flooded CELL. 😂 😂 😂 😂
 
Trotter said:
My three AGM’s are looked after by 200 watt solar and a Ctek D 250 + Smartpass. The only problem I’ve had so far, and it’s very early days, is with my use of an electric kettle, when parked for more than a few days, with little sun.
It’s all a learning curve. Being locked down doesn’t help.
Click to expand...

We have experienced the same even the smallest of kettle 600w kills our batteries .
Slow cooker,, hover, microwave ,hair dryer ,toaster all ok ..so its gas only for kettle. But there again we do have about 10 cups of tea a day.😀😀😀😀😀
 
Ah - we've been told the boat has 1060W of solar which on a decent day should be able to handle 3 batteries.
From other threads we gather these may well be new.
Not sure that being on a boat much alters the charger requirements which will all need proper AGM profiles.
Do boat engines get run much? Probably not long and often enough to recharge fairly well drained batteries.
So if the engine is to of any use it will need a B2B to get the voltage high enough to deliver 14.8V for a sustained period of charging.
 
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