robavery
New member
My alternator is charging my batteries at 14.2 v is this correct or should it be at least 14.4??
Battery Charging
- Thread starter robavery
- Start date
orizaba
New member
depending on the alternator and assuming you have no booster regulators etc fitted 14.2 is pretty good .most car alternators stop at about 13.8 as standard
jimbaerselman
New member
Depends how low the battery is as well. If it's taking all the current the alternator can deliver, the voltage will drop quite a bit
On the other hand, if the battery is fully charged, and the alternator is still pushing out 14.2v, you're going to lose some water. At full charge, it's desirable to supply a max of 13.6v
(all assuming lead acid batteries).
On the other hand, if the battery is fully charged, and the alternator is still pushing out 14.2v, you're going to lose some water. At full charge, it's desirable to supply a max of 13.6v
(all assuming lead acid batteries).
brianrunyard
New member
Sounds ok to me.
Out of interest, how accurate is your reading of 14.2v? What are you measuring it with?
Out of interest, how accurate is your reading of 14.2v? What are you measuring it with?
johnalison
Well-known member
It may also depend on how & where you measure the voltage; I tend to use a repeater in my Raytheon display which I have found overreads 0.1 volt when compared with a meter on the batteries.
Chris_Robb
Well-known member
Sterling products (digital alternator regulator/booster) recommend charging lead acid at 14.8V - but also say that you will need to fill with water regularly.
I think it is quite important to understand your whole charging set up. Is it a standard alternator - how is it connected to the batteries (splitting diode or battery 1 -2 both switch). A splitting diode will have a voltage loss over it of up to .5V(??) so if you have one, you will almost certainly have a booster of some sort to get 14.2V. If you a battery switch type, then it may be a straight alternator - you will need to watch what happens to the batteries if you motor for extended periods ie in excess of 12 hours.
I am definitley not an expert on this subject - and have been having a lot of "fun" with my own electric this year - and learning fast! If you are not on a marina shore power - ie on a mooring - then sorting out your charging become an imperative - especially if you want the cold beers!
You don't show anything in your details - like boat and area - would be useful as people can be more helpful in their replies.
Chris
I think it is quite important to understand your whole charging set up. Is it a standard alternator - how is it connected to the batteries (splitting diode or battery 1 -2 both switch). A splitting diode will have a voltage loss over it of up to .5V(??) so if you have one, you will almost certainly have a booster of some sort to get 14.2V. If you a battery switch type, then it may be a straight alternator - you will need to watch what happens to the batteries if you motor for extended periods ie in excess of 12 hours.
I am definitley not an expert on this subject - and have been having a lot of "fun" with my own electric this year - and learning fast! If you are not on a marina shore power - ie on a mooring - then sorting out your charging become an imperative - especially if you want the cold beers!
You don't show anything in your details - like boat and area - would be useful as people can be more helpful in their replies.
Chris
srp
Well-known member
Doesn't it depend what sort of battery it is? I've heard that 14.2v is the maximum recommended for sealed AGM and 14.8v the max for ordinary lead-acid that can be topped up regularly. If that is so, then I would say that your alternator's ok.
Chris_Robb
Well-known member
According to Charles Sterling. Gel or sealed batteries have no place on a boat.
By this I think he means that (provided you are not on marina shorpower) you need to charge fast and furiously. Gel is slow to charge (up to 8 times slower??) and cannot take more than 14.2 -4v. Sealed batteries have to be treated with kid gloves as you cannot replenish the water. so hense a 14.4 charging limit. These may be ideal for cars.
By this I think he means that (provided you are not on marina shorpower) you need to charge fast and furiously. Gel is slow to charge (up to 8 times slower??) and cannot take more than 14.2 -4v. Sealed batteries have to be treated with kid gloves as you cannot replenish the water. so hense a 14.4 charging limit. These may be ideal for cars.
halcyon
Well-known member
It depends on the battery manufacture, at least one states AGM's they make should be charged a constant 14.8 volt. Back in the 1980's we used to manufacture a special battery charger setting for Westerly who used AC delco Freedom batteries. These chrged upto 15.4 volt and floated at 14.6 ( from memory ), as apposed to a standard 14.2 / 3 float 13.6 volt.
So as I have said before check who your battery manufacture is, and then there charging spec, not some firms add on sales blurb.
In passing 14.2 volt sounds reasonable, and if you do not have battery problems, not worth worrying about.
Brian
So as I have said before check who your battery manufacture is, and then there charging spec, not some firms add on sales blurb.
In passing 14.2 volt sounds reasonable, and if you do not have battery problems, not worth worrying about.
Brian
2Tizwoz
Well-known member
Bought a new one today.
Must look after it.
Lead prices have doubled
They are apparently set to fall later in the year but battery prices are set to rise further in the short term.
Must look after it.
Lead prices have doubled
They are apparently set to fall later in the year but battery prices are set to rise further in the short term.
halcyon
Well-known member
[ QUOTE ]
According to Charles Sterling. Gel or sealed batteries have no place on a boat.
By this I think he means that (provided you are not on marina shorpower) you need to charge fast and furiously. Gel is slow to charge (up to 8 times slower??) and cannot take more than 14.2 -4v. Sealed batteries have to be treated with kid gloves as you cannot replenish the water. so hense a 14.4 charging limit. These may be ideal for cars.
[/ QUOTE ]
Having a quick look at Fullriver AGM and Gell tech leaflet.
Charge must be constant voltage at 14.7 volt, at this voltage they will take a charge rate of around 40% of there capacity, ie 40 amp for a 100 amp hr battery.
They do not require multi-stage charging. In normal use they do not gas, so do not loose electrolyte, which is a problem that normal lead acid suffer, hense the float charge rate to limit gassing.
As I said check your battery manufacture for charging.
Brian
According to Charles Sterling. Gel or sealed batteries have no place on a boat.
By this I think he means that (provided you are not on marina shorpower) you need to charge fast and furiously. Gel is slow to charge (up to 8 times slower??) and cannot take more than 14.2 -4v. Sealed batteries have to be treated with kid gloves as you cannot replenish the water. so hense a 14.4 charging limit. These may be ideal for cars.
[/ QUOTE ]
Having a quick look at Fullriver AGM and Gell tech leaflet.
Charge must be constant voltage at 14.7 volt, at this voltage they will take a charge rate of around 40% of there capacity, ie 40 amp for a 100 amp hr battery.
They do not require multi-stage charging. In normal use they do not gas, so do not loose electrolyte, which is a problem that normal lead acid suffer, hense the float charge rate to limit gassing.
As I said check your battery manufacture for charging.
Brian
Chris_Robb
Well-known member
Thats interesting - Charles rants must be a little out of date!
