battery charger

R

roger777

Petty Officer 3rd Class
Joined
Aug 24, 2008
Messages
96
I am looking for a bettery charger I can use while offshore. The only chargers I see are the kind that plug in the wall. Are there any that can run off a 12 volt battery and charge that same battery.. I carry a third battery when offshore but when night fishing with the family I run. livewell,cockpit lights,cabin lights, tv and dvd for the kids, mini fan for the wife,swordlight,radio, bilge kicking on and off, ect... Just want some peace of mind. Would hate to get stuck with the family..
thanks
 
Silvertip

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,762
Re: battery charger

Sorry but perpetual motion hasn't been invented yet. A battery is like a bucket of water. Once it's empty it can only be refilled from another bucket (or hose). You can charge one battery from another using jumper cables, but you cannot charge the same discharged battery with some magical device. Only a generator can do that off shore. Why not wire all of your batteries into the charging system on the boat. With the use of a battery switch you can select which battery you want to use to power accessories thus leaving the start battery off-line so you won't discharge it. This topic has been discussed to death on this and other forums so do a search on "Battery Switches" or "dual battery systems". We know you have three batteries but the principle is the same.
 
R

roger777

Petty Officer 3rd Class
Joined
Aug 24, 2008
Messages
96
Re: battery charger

I am not looking for a magical device. I am looking for a battery charger that can be used froma 12 volt source rather thaen a plug in type.Not necessesarily charging off a dead battery.. Maybe a battery charger powered by a cigarette lighter or something. I just want to keep my batteries fully charged. I am going to be in the keys for 3 days and we will be camping on an island with no power. I dont want to lug around a generator.I do have dual perko switches. I guess i could run the motor for a while but I was looking for another way to charge them(quieter and gas sufficient).. The boat is going to be the only power source which we will be using alot.Another thing, I do have a pull cord for my motor. Has anyone had to pull start a 150hp? Just wondering how difficult it would be.
Thanks
 
boat1010

boat1010

Senior Chief Petty Officer
Joined
Mar 10, 2009
Messages
781
Re: battery charger

I don't think you are grasping what Silvertip is saying. No matter what you "power" the battery charger from that is 12 volts is something that you have on your boat. So why not just use the battery that you were going to drain to use the charger. Hook all three to the boat generator so when you are running the boat you would be charging all three batteries. Then you can select which one you want to run stuff off of. But what you want to do can only be done by running a generator or using the boat charging system.
 
Chiliando

Chiliando

Petty Officer 2nd Class
Joined
Jan 10, 2009
Messages
120
Re: battery charger

Why not take a marine battery booster? I have the two batteries on a dual switch but I always take a fully charged booster. In your case it would start the engine. I would so as the others have stated and attach the third battery to your other two. With 3 batteries and a booster you should be good to go.
 
R

roger777

Petty Officer 3rd Class
Joined
Aug 24, 2008
Messages
96
Re: battery charger

boat1010 said:
I don't think you are grasping what Silvertip is saying. No matter what you "power" the battery charger from that is 12 volts is something that you have on your boat. So why not just use the battery that you were going to drain to use the charger. Hook all three to the boat generator so when you are running the boat you would be charging all three batteries. Then you can select which one you want to run stuff off of. But what you want to do can only be done by running a generator or using the boat charging system.
Click to expand...


I understand what silvertip is saying. I dont plan on running the boat for long periods of time(to charge batteries). i dont know how long you need to run the boat to put a good charge on the batteries. I know that I can designate switches for certain batteries. Maybe I am overreacting thinking I am going to drain the batteries quicker then they will drain but I would rather take precaution. If it was only myself I probably would not even be posting.. I would just like to know if there is a way to charge batteries without having to run motors or without plugging a charger into a wall.. I guess that would have been a simpler question.
Thanks
 
C

captharv

Petty Officer 2nd Class
Joined
Mar 26, 2005
Messages
187
Re: battery charger

Solar panel and charging regulator. To get about 10 amps, the cost is about what Honda 1000 cost.
Not trying to be a wise a**, but your question has no answer.
I am an electronic engineer by trade..
Answer to the other question. Dependant of what size alternator and battery usage, could take as much as 4 hours to recharge to 80%.
Just where are you boat camping?
I have a 24' cruiser. My ships batteries are 6 volt, 220AH golf cart batteries. 220 amp hours will run my fridge, TV, lights, etc for almost 3 days without starting the engine. However, we also usually run air at night, so I use a Honda 2000.
Runs the air, battery charger, and fridge all night on a gallon and a half of fuel.
 
scipper77

scipper77

Commander
Joined
Sep 30, 2008
Messages
2,106
Re: battery charger

I would recommend a spare battery. And make sure the spare is fully charged before you leave for your trip. You could also bring one of those portable power packs for jump starting cars, If you need to use it however you are going to have to bite the bullet and let the boats charging system recharge the battery.
 
slasmith1

slasmith1

Lieutenant Junior Grade
Joined
Dec 2, 2008
Messages
1,028
Re: battery charger

The answer to your question is a very simple no.
 
R

roger777

Petty Officer 3rd Class
Joined
Aug 24, 2008
Messages
96
Re: battery charger

Chiliando said:
Why not take a marine battery booster? I have the two batteries on a dual switch but I always take a fully charged booster. In your case it would start the engine. I would so as the others have stated and attach the third battery to your other two. With 3 batteries and a booster you should be good to go.
Click to expand...

I think I am going to pickup a booster.. I have one my wife picked up a year ago on clearance somewhere. It wont even jump my kids big wheels. I have to pickup a good one..
thanks
 
R

roger777

Petty Officer 3rd Class
Joined
Aug 24, 2008
Messages
96
Re: battery charger

captharv said:
Solar panel and charging regulator. To get about 10 amps, the cost is about what Honda 1000 cost.
Not trying to be a wise a**, but your question has no answer.
I am an electronic engineer by trade..
Answer to the other question. Dependant of what size alternator and battery usage, could take as much as 4 hours to recharge to 80%.
Just where are you boat camping?
I have a 24' cruiser. My ships batteries are 6 volt, 220AH golf cart batteries. 220 amp hours will run my fridge, TV, lights, etc for almost 3 days without starting the engine. However, we also usually run air at night, so I use a Honda 2000.
Runs the air, battery charger, and fridge all night on a gallon and a half of fuel.
Click to expand...

I am going to be headed to the middle keys not sure which one yet(got any suggestions).. I wasn't sure about how fast the batteries will drain. I usually only run a few things for 6-10 hours at a time without a problem but I know I will run alot more than usual. Judging by what you run on 6volts I am sure I will be fine..
Thanks
 
R

reelfishin

Captain
Joined
Mar 19, 2007
Messages
3,043
Re: battery charger

If your going to be traveling a distance, and taking a chance of running all your batteries dead, you may just simply want to isolate the main battery, maybe even add a second or third deep cycle and not drain the main battery at all.
Then for redundancy, carry the power pack jump starter. I'd buy a good one, something commercial if you really need to depend on it.
A few small solar panels will also help, even the cheap one's you buy at Harbor Freight will help maintain your batteries or jump pack.
Other than that, get a small portable generator but even a small generator won't give you the high amperage boost a good power pack will.

I have a few of those $20 solar panels from HF which I place on the dash in the sun to maintain my boat when docked, they do prevent the batteries from going dead during the week when I'm not around, and do add some life to my deep cycle batteries while I'm out fishing during the day.
 
Silvertip

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,762
Re: battery charger

Let me try this one more time. When you ask to recharge a battery from a 12 volt source like a cigarette lighter, where do you think that 12 volts comes from? It comes from another battery and that battery is not an inexhaustable source of electricity. So all you are accomplishing is sucking 12 volts from one battery, draining it, and putting it into another battery. So you still end up with the same amount of engergy only swapping it between batteries. The end result is you still have one dead battery.
 
J

Joseph10

Petty Officer 3rd Class
Joined
Feb 28, 2009
Messages
76
Re: battery charger

Actually, what you will end up with if you hook a dead battery to a charged battery is 2 batteries with a near equal engery content (i.e. both battery's will now be only half charged). And since the terminal voltage of the charged battery will be nowhere near the voltage output of an alternator, this will likely take many hours to accomplish.
 
S

Scupper Guppy

Cadet
Joined
Dec 18, 2008
Messages
7
Re: battery charger

I have seen these battery chargers for sale on Ebay. Pretty handy. The same folks also sell fuel separator filters that change the water in your fuel into a burnable mixture. Something to check out!
 
J

Jeep Man

Commander
Joined
Oct 17, 2008
Messages
2,803
Re: battery charger

You said you didn't want to lug a generator around. I don't think your giving modern generators an even shake. Honda(and other name brands) make wonderful, small, light units that are extremely quiet. I was on a job site recently and was having a conversation with another contractor. We were standing very close to a Honda 3000. I thought it was off, but in fact was rumnning the entire time.
 
Rickairmedic

Rickairmedic

Commander
Joined
Apr 24, 2009
Messages
2,576
Re: battery charger

I have a couple of the HF $20.00 solar chargers I kep on vehicles that dont get used daily just to keep the batteries up and they work great for that use. I would grab a couple of them to use on your ( spare ) batteries and keep one on the main battery as well but not use the main battery for anything other than running the boat motor while out.


Rick
 
H

H20Rat

Vice Admiral
Joined
Mar 8, 2009
Messages
5,201
Re: battery charger

Jeep Man said:
You said you didn't want to lug a generator around. I don't think your giving modern generators an even shake. Honda(and other name brands) make wonderful, small, light units that are extremely quiet. I was on a job site recently and was having a conversation with another contractor. We were standing very close to a Honda 3000. I thought it was off, but in fact was rumnning the entire time.
Click to expand...

i've been next to the smallest honda EU series generator and didn't even know it was running, i was literally 2 feet away! they are pricey, but if you want a very quiet generator, they are probably tops
 
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