I would like to know what are the benefits of using an onboard charger
instead of a portable charger.

I have been using rechargers for many type of household electronic
equipments (such as digital carmera, toy cars...etc). Therefore, I am
very familiar with portable recharger. But I notice that there are
many onboard rechargers available in marine supply store when I was
trying to shop for a recharger. I can imagine one benefit of having an
onboard recharger: It is neatly mounted inside the battery compartment,
instead of being sliding around on the floor of the battery
compartment. What are the other benefits? Can I connect the recharger
with the various batteries (I have 2 batteries, will be 3 in the
future) in a permanent fashion instead of using alligator clips? Then
I only need to run a power cord from an outdoor power outlet to the
receptacle of the recharger. Then I don't need to remember which
alligator clip goes to which terminal on the battery. That will be a
very nice feature if I understand this correctly.

A side-question:
Should I use a 10-amp or a 15-amp battery charger? I believe a
regular 110-volt household power outlet should provide at least 15-amp.
This means either 10-amp or 15-amp charger should work if I understand
this correctly. Then why would one person choose 10-amp over the
15-amp version or the other way around? Does a 15-amp version simply
charge the batteries faster? If I want to charge two 12-volt batteries
plus one 24-volt battery overnight (12-hours), does choosing the 15-amp
version makes any difference to me?

I urgently need to know this info because I need to buy a battery
recharger pretty soon.

Thanks in advance for any info.

Jay Chan

On Sun, 13 Nov 2005 20:23:38 -0800, jaykchan wrote:

I would like to know what are the benefits of using an onboard charger
instead of a portable charger.


Again, in basically an open boat, a portable charger makes sense. You can
use it for other purposes as well, like charging your car battery if
you leave the lights on, or if it's a GOOD one (see below), for keeping
your batteries charged through the winter.

Current draw at 120VAC (your "15A circuit") is not the same as the current
output TO the battery: the output is about 10 times as much (1/10 the
voltage, 10x the current, not including efficiency) So the current draw is
not a factor.

Yes, the more current, the faster the battery will charge, but you can't
use TOO much charging current: typically 1/10 the ampacity, which is about
10-15A for a Group 24.

Problem is, the cheap "10A" chargers don't really put out 10 amps, so some
buy the 15A instead. I'd buy a GOOD 10A "Smart" Charger, like the Xantrex
Statpower series, which actually DOES put out 10A with a proper charging
"curve". Your batteries will thank you!

Lloyd Sumpter
"Far Cove" Catalina 36 c/w onboard Xantrex 40A

wrote:

I would like to know what are the benefits of using an onboard charger
instead of a portable charger.

I have been using rechargers for many type of household electronic
equipments (such as digital carmera, toy cars...etc). Therefore, I am
very familiar with portable recharger. But I notice that there are
many onboard rechargers available in marine supply store when I was
trying to shop for a recharger. I can imagine one benefit of having an
onboard recharger: It is neatly mounted inside the battery compartment,
instead of being sliding around on the floor of the battery
compartment. What are the other benefits? Can I connect the recharger
with the various batteries (I have 2 batteries, will be 3 in the
future) in a permanent fashion instead of using alligator clips? Then
I only need to run a power cord from an outdoor power outlet to the
receptacle of the recharger. Then I don't need to remember which
alligator clip goes to which terminal on the battery. That will be a
very nice feature if I understand this correctly.

A side-question:
Should I use a 10-amp or a 15-amp battery charger? I believe a
regular 110-volt household power outlet should provide at least 15-amp.
This means either 10-amp or 15-amp charger should work if I understand
this correctly. Then why would one person choose 10-amp over the
15-amp version or the other way around? Does a 15-amp version simply
charge the batteries faster? If I want to charge two 12-volt batteries
plus one 24-volt battery overnight (12-hours), does choosing the 15-amp
version makes any difference to me?

I urgently need to know this info because I need to buy a battery
recharger pretty soon.

Thanks in advance for any info.

Jay Chan


Jay,

Google "Guest" battery chargers for more information. They are one of
many onboard chargers available. I think they also make marine portable
chargers for single battery use.

The difference is pretty simple. Since you have more than one battery,
an onboard charger is the way to go. It will charge, monitor, and
maintain each battery as if each had it's own charger. You can also buy
models that handle one 12V and one 24V at the same time (or other
configurations) that are common on bass boats that have a 12V starting
battery and a 24V or 36V deep cycle trolling motor battery.

I would never charge two batteries with a conventional battery charger
at the same time. They are never the same so while on is starving for a
charge, the other may overheat - or worse.

Dan

Again, in basically an open boat, a portable charger makes sense. You can
use it for other purposes as well, like charging your car battery if
you leave the lights on, or if it's a GOOD one (see below), for keeping
your batteries charged through the winter.

Yes, the boat is an open boat. But the batteries are inside the center
console, and the small door opening to the interior of the center
console is not big enough for me to easily work around. I would prefer
the connection to be kind of permanent instead of using alligator clips
of a portable charger.

Current draw at 120VAC (your "15A circuit") is not the same as the current
output TO the battery: the output is about 10 times as much (1/10 the
voltage, 10x the current, not including efficiency) So the current draw is
not a factor.

Yes, the more current, the faster the battery will charge, but you can't
use TOO much charging current: typically 1/10 the ampacity, which is about
10-15A for a Group 24.

Honestly, I don't quite understand this. I appreciate your effort in
trying to explain this to me. I figure you are saying that I don't
need to worry about what the power rating in the household power
outlet. Thanks.

Problem is, the cheap "10A" chargers don't really put out 10 amps, so some
buy the 15A instead. I'd buy a GOOD 10A "Smart" Charger, like the Xantrex
Statpower series, which actually DOES put out 10A with a proper charging
"curve". Your batteries will thank you!

Thanks for the suggestion. I will keep an note on this.

Jay Chan

The difference is pretty simple. Since you have more than one battery,
an onboard charger is the way to go. It will charge, monitor, and
maintain each battery as if each had it's own charger.

Sound good to me. Seem like an onboard charger is the way to go.

You can also buy models that handle one 12V and one 24V
at the same time (or other configurations) that are common
on bass boats that have a 12V starting battery and a 24V or
36V deep cycle trolling motor battery.

This sounds odd. If they only have one battery for starting engine,
and another 24V or 36V battery for the trolling motor. Then all the
other electronic equipments (such as fish-finder, VHF radio) may have
to connect to the 12V battery that is supposed for starting engine.
This doesn't sound like something that I would want to do.

The other thing is that I cannot find any 24V battery. Seem like
people tend to use two 12V batteries in serie to make a 24V system.
This kind of make sense. Then we can use those two 12V batteries as
backup just in case the starting battery and the house battery both go
dead. This is just that two 12V batteries may be a bit too heavy and
take too much room. I am just hoping that I can find one single 24V
battery, and I am still looking.

I would never charge two batteries with a conventional battery charger
at the same time. They are never the same so while on is starving for a
charge, the other may overheat - or worse.

Good to know that the onboard charger has this benefit. Thanks.

I have decided to get an onboard charger tomorrow. The onboard charger
will charge those two existing 12V batteries. In the future when I get
a 24V trolling motor and two 12V batteries for the trolling motor, I
will get another onboard charger to charge those two new trolling motor
batteries. This sounds like a plan.

Jay Chan

wrote in message
oups.com...
The difference is pretty simple. Since you have more than one battery,
an onboard charger is the way to go. It will charge, monitor, and
maintain each battery as if each had it's own charger.

Sound good to me. Seem like an onboard charger is the way to go.

You can also buy models that handle one 12V and one 24V
at the same time (or other configurations) that are common
on bass boats that have a 12V starting battery and a 24V or
36V deep cycle trolling motor battery.

This sounds odd. If they only have one battery for starting engine,
and another 24V or 36V battery for the trolling motor. Then all the
other electronic equipments (such as fish-finder, VHF radio) may have
to connect to the 12V battery that is supposed for starting engine.
This doesn't sound like something that I would want to do.

The other thing is that I cannot find any 24V battery. Seem like
people tend to use two 12V batteries in serie to make a 24V system.
This kind of make sense. Then we can use those two 12V batteries as
backup just in case the starting battery and the house battery both go
dead. This is just that two 12V batteries may be a bit too heavy and
take too much room. I am just hoping that I can find one single 24V
battery, and I am still looking.

I would never charge two batteries with a conventional battery charger
at the same time. They are never the same so while on is starving for a
charge, the other may overheat - or worse.

Good to know that the onboard charger has this benefit. Thanks.

I have decided to get an onboard charger tomorrow. The onboard charger
will charge those two existing 12V batteries. In the future when I get
a 24V trolling motor and two 12V batteries for the trolling motor, I
will get another onboard charger to charge those two new trolling motor
batteries. This sounds like a plan.

Jay Chan


You can find a 24v battery, but you would not want to pay for it. Get 2 12V
deep cycle batteries. Walmart sells them for about $50-60. Warranteed for
2 years full replacement I think. Run the trolling motor off these
batteries, and keep a set of jumper cables in the boat and if the single
starting battery is dead, jump it. If you already have duel batteries, just
run the trolling motor batteries separate. I have Grp 30 size batteries on
a Minn Kota 65AP, but I may go 3 days without recharging. Since I store the
boat where there is no power, I pull the batteries and charge at home. I
use a Vector 1092 smart charger. About $65 and does a great job. Much
better job than the Shumacher I replaced.

You can find a 24v battery, but you would not want to pay for it. Get 2 12V
deep cycle batteries. Walmart sells them for about $50-60. Warranteed for
2 years full replacement I think.

This explains the reason why I cannot find any 24V battery in local
marine supply stores. This means I should forget about using one
single 24V battery, and should concentrate on getting two 12V batteries
that are much less costly.

Run the trolling motor off these batteries, and keep a set of jumper
cables in the boat and if the single starting battery is dead, jump it.

I assume the way to jump a dead battery in the boat is exactly the same
as jumping a dead battery in a car (honestly I had done this multiple
times to my car because I tend to forget to turn off the headlight).
This sounds easy enough. Thanks for this suggestion. This means I
will have a set of backup batteries ready to go in case the starting
battery goes dead.

If you already have duel batteries, just run the trolling motor batteries separate.

This sounds like a good way to avoid messing up the existing battery
connection while still keeping the option of jumping started the dead
starting battery with a set of jumper cables. This is quite likely the
way that I will go. Thanks.

Jay Chan

Jay, is this for fresh water or salt water use? If salt water, my only
advice as to an on board charger is, be sure it's compatible and/or has a
good warranty. I've just completed my third summer of salt water use and
have been amazed at the corrosive and destructive nature of the salt!
wrote in message
oups.com...
I would like to know what are the benefits of using an onboard charger
instead of a portable charger.

I have been using rechargers for many type of household electronic
equipments (such as digital carmera, toy cars...etc). Therefore, I am
very familiar with portable recharger. But I notice that there are
many onboard rechargers available in marine supply store when I was
trying to shop for a recharger. I can imagine one benefit of having an
onboard recharger: It is neatly mounted inside the battery compartment,
instead of being sliding around on the floor of the battery
compartment. What are the other benefits? Can I connect the recharger
with the various batteries (I have 2 batteries, will be 3 in the
future) in a permanent fashion instead of using alligator clips? Then
I only need to run a power cord from an outdoor power outlet to the
receptacle of the recharger. Then I don't need to remember which
alligator clip goes to which terminal on the battery. That will be a
very nice feature if I understand this correctly.

A side-question:
Should I use a 10-amp or a 15-amp battery charger? I believe a
regular 110-volt household power outlet should provide at least 15-amp.
This means either 10-amp or 15-amp charger should work if I understand
this correctly. Then why would one person choose 10-amp over the
15-amp version or the other way around? Does a 15-amp version simply
charge the batteries faster? If I want to charge two 12-volt batteries
plus one 24-volt battery overnight (12-hours), does choosing the 15-amp
version makes any difference to me?

I urgently need to know this info because I need to buy a battery
recharger pretty soon.

Thanks in advance for any info.

Jay Chan

Jay, is this for fresh water or salt water use? If salt water, my only
advice as to an on board charger is, be sure it's compatible and/or has a
good warranty. I've just completed my third summer of salt water use and
have been amazed at the corrosive and destructive nature of the salt!

I will use the boat for both freshwater and sal****er. I bought a
ProMariner onboard charger last evening. It states that it can handle
sal****er environment. I have a feeling that I will be OK because the
charger will be mounted inside the center console (a protected
compartment area), and that area is dry. How did yours get to be in
such a bad shape? Did you put it in an area that was open to the
elements? Did you leave the boat in a marina instead of on a trailer?

Thanks for the warning though.

Jay Chan

I didn't loose a charger but other things like:
battery cables that had steel ends rusted into two pieces.
a Perko batery selector switch that somehow got water inside and drained
batteries and apparently shorted out the rectifyer charging circuit.
Even though used, I just replaced the axles and springs (one axle was new
three years ago!)
studs on the engine, exposed threads are rusted badly
etc, etc,
LD

wrote in message
oups.com...
Jay, is this for fresh water or salt water use? If salt water, my only
advice as to an on board charger is, be sure it's compatible and/or has
a
good warranty. I've just completed my third summer of salt water use
and
have been amazed at the corrosive and destructive nature of the salt!

I will use the boat for both freshwater and sal****er. I bought a
ProMariner onboard charger last evening. It states that it can handle
sal****er environment. I have a feeling that I will be OK because the
charger will be mounted inside the center console (a protected
compartment area), and that area is dry. How did yours get to be in
such a bad shape? Did you put it in an area that was open to the
elements? Did you leave the boat in a marina instead of on a trailer?

Thanks for the warning though.

Jay Chan