davidfox
New member
I have a cetrex smart charger thingy on the boat, when i am not on board, i leave it charging all the time (it sort of trickle charges) is that the correct way to do things?
Batteries and how to look after them
- Thread starter davidfox
- Start date
parito
New member
Correct way is to observe voltages - floating voltage on trickle charge is ~13.4V-13.7V, if that is what you see when you come back onto your boat this should be ok.
Is it ok to leave power on your boat when you're away is a matter of marina's policy as well as how you yourself feel about it and if your insurance covers it
pvb
Well-known member
Theoretically it shouldn't harm the batteries. However, I don't like leaving shorepower connected for long periods, so prefer to charge the batteries then disconnect the charger.
Trundlebug
Active member
Smart chargers are meant to be left connected; if your intention is to look after your batteries, that's the best thing to do.
The charger cuts out when the batteries are fully charged, then just sits and monitors the voltage.
As the batteries self discharge naturally the voltage slowly falls. The charger kicks in at the optimum point and boosts them a bit, then cuts out and monitors again.
This pattern prevents sulphation and keeps the batteries in top condition.
Disconnecting every time you leave the marina will not get the best out of the charger, or the batteries.
One point to add, you must check your batteries regularly to make sure the fluid levels are OK and are achieving full charge so that the charger cuts out.
Last weekend I noticed the charger on my starter battery was still bulk charging after several hours, so I switched it off and checked the fluid levels.
One cell in the starter battery was low. I topped it up, switched on the charger and hey presto it registered fully charged and cut out immediately.
So, if you have a weak cell anywhere the charger will find it and boil it dry in an attempt to restore the correct voltage.
Regular vigilance is required. (Note, I hadn't checked fluid levels for about 6 months - lesson learned).
The charger cuts out when the batteries are fully charged, then just sits and monitors the voltage.
As the batteries self discharge naturally the voltage slowly falls. The charger kicks in at the optimum point and boosts them a bit, then cuts out and monitors again.
This pattern prevents sulphation and keeps the batteries in top condition.
Disconnecting every time you leave the marina will not get the best out of the charger, or the batteries.
One point to add, you must check your batteries regularly to make sure the fluid levels are OK and are achieving full charge so that the charger cuts out.
Last weekend I noticed the charger on my starter battery was still bulk charging after several hours, so I switched it off and checked the fluid levels.
One cell in the starter battery was low. I topped it up, switched on the charger and hey presto it registered fully charged and cut out immediately.
So, if you have a weak cell anywhere the charger will find it and boil it dry in an attempt to restore the correct voltage.
Regular vigilance is required. (Note, I hadn't checked fluid levels for about 6 months - lesson learned).
BAtoo
New member
When in a marina its what I did for many years with no problem & if I ever go back in its what I would do again. Seemed to work fine.
parito
New member
Smart chargers are only smart because they charge 3-8 different phases... leaving 220V plugged into your boat might be ok, might be not..
All the smart chargers I encountered or read about do not switch off when the battery was charged - they hold "float charge" voltage, which is ~13.5V
I personally consider much safer to leave a boat on 10W-15W solar panel to keep batteries topped up, after I charge them with a "smart" charger beforehand.
All the smart chargers I encountered or read about do not switch off when the battery was charged - they hold "float charge" voltage, which is ~13.5V
I personally consider much safer to leave a boat on 10W-15W solar panel to keep batteries topped up, after I charge them with a "smart" charger beforehand.
Trundlebug
Active member
With respect, they're not smart chargers.
Smart chargers go through a float phase of 13.5-13.8v but then cut out after some time to "pulse" which means they sit and do nothing except monitor the battery voltage. When it drops to 12.7v they "pulse" at 14.8v for about 30 seconds, then cut out and monitor again.
It can take several hours, or even days for the voltage to fall to 12.7v for the next pulse, if the batteries are in good condition.
Have a look for yourself: http://www.ctekchargers.co.uk/?gclid=CP2U45nU5rgCFUXKtAodUl0Abg
Chargers that don't cut out are not "smart" chargers.
parito
New member
My appologies, you are right here - I do use ctek m200 myself, I just never managed to observe a drop to 12.7V it seems
From Ctek manual
Maintenance charging - Pulse (Lamp 4)
Charging varies between 95% and 100% state of charge. The battery receives a pulse when the voltage drops and keeps the battery
in perfect condition when it is not in use. The charger can be connected for months at a time. The charger continuously measures the
terminal voltage to determine whether a charging pulse should be initiated. If the battery is loaded and/or the battery’s terminal voltage
drops the charger starts a charging pulse until the terminal voltage reaches the set level. The charging pulse is then discontinued and
the cycle is repeated infinitely. If the terminal voltage drops below a lower limit, the charger automatically goes back to the beginning
of the charging curve.
reeac
Well-known member
It would require a big survey to answer that question. My Elecsol batteries get a 24h. charge in December and again April plus charging when I run the engine [say 50h. p.a.] plus a good shore power charge if we visit a marina. So far they've done 7 years with no problems so lack of float charging hasn't done any obvious harm.
davidfox
New member
I like your answer the best! I will certainly pay more attention to fluid levels in future tho