charging my marine batteries

[cali27]

Can I charge my batteries in my garage without taking them out of the boat and disconnecting everything? I will be using a minn kota charger. Just want to make sure it wont ruin anything that is connected but turned off.

thanks

 

[russ010]

that's how I do it with onboard chargers - and it's how I did it before with portable chargers.

 

[cali27]

Thanks Russ

 

[longjohn119]

That's how I do it. I use little 1 1/2 amp Schumacher 3 state chargers https://www.farmandfleet.com/produc...ml?lref=/catalog/find.aspx?t=battery+chargers and bolt them right to my battery boxes. The battery boxes go in the boat in the Spring and (almost) never get removed until Fall. The charger stays hooked up to the battery (But not necessarily plugged into an outlet) 24/7/365 until it gets replaced. The 1st one I bought in Fall '03 and it's still going strong. The guy that recommended it to me has 25 of them, one on each one of his collector/show cars and has yet to have one fail.

Some of Schumacher's chargers are junk but this model they got right. Minnkota is also one of the few places that have gotten switch mode technology chargers right but I can buy 3 of the Schumachers for the same price and probably have enough left over to get lunch at McDonald's. The only downside to the Schumacher charger is it's only 1 1/2 amp so it takes a good 24 hours to recharge a heavily used battery but that's also one of it's strong points too, deep cycle batteries last longer if they are slowly charged.

Switch mode charger/power supply reliability almost always comes down to the quality of the electrolytic caps used and that's the first place the Bean Counter try to cut corners every time so the Marine industry is learning what computer and VCR manufacturers had to learn the hard way 20 years ago ... You can't cut corners on the caps in a switching mode power circuit just to squeeze out a few more pennies of profit, in the long run you'll lose 100 times that in warranty claims and bad reputation. Unfortunately that hasn't seemed to stop the Bean Counters from making the same mistakes over and over again, it's just poor teaching in all the business schools that makes them all "penny wise and dollar foolish" ... Plus it doesn't help that most corporations leave the dollar decisions to the technically inept who don't even understand the basics of electronics technology.

 

[redbug]

i would get at least a 5 amp charger mine is a 4 bank 15amp dual pro. that way if you want to fish 2 days in a row you will have a fully charged battery over night

 

[Hanr3]

I use a Schumacher Ship N Shore charger. Its a portable unit and has a 2amp, 10amp, and 15 amp settings. I use it for my riding mower, boat, and car batteries. Worth the $50. Its mirco processor controlled, auto shut off, trickle charge if needed, plus it will tell you the current charge status level of the battery, has a diagnositc mode.

 

[russ010]

I use a Schumacher Ship N Shore charger. Its a portable unit and has a 2amp, 10amp, and 15 amp settings. I use it for my riding mower, boat, and car batteries. Worth the $50. Its mirco processor controlled, auto shut off, trickle charge if needed, plus it will tell you the current charge status level of the battery, has a diagnositc mode.

I've got the same charger... that thing is awesome.

It told me when I had a bad battery, took it to Wally world to replace, let them run their 2 hour diagnostic - and in the end, it was still a bad battery.

 

[dyeguy1212]

I use a Schumacher Ship N Shore charger. Its a portable unit and has a 2amp, 10amp, and 15 amp settings. I use it for my riding mower, boat, and car batteries. Worth the $50. Its mirco processor controlled, auto shut off, trickle charge if needed, plus it will tell you the current charge status level of the battery, has a diagnositc mode.

I've got a question for you and russ then, excuse the hijack. When you leave your charger on, does it say 100% for a long time before shutting off? And when it is no longer charging, does it completely shut off, or does it just switch to a different high pitched whine?

I can't decide if mine is screwed up or not. It never behaved quite right, then it experienced a flood in my basement, but it still seems to work okay, and it charges the batteries. I've just never trusted the auto shut off, because it will say 100% with 13V, and still charge for another 2 hours, still giving the same read out. When it finally does stop charging, it will alternate between the whine when its plugged in but not connected to a battery, and the charging whine, switching every 5 seconds or so.

 

[russ010]

sounds like it's working right to me. Mine never actually shut off (if you are referring to powering off), it would get fully charged to 100%, then keep a float charge around 13.1-13.3 volts.

that high pitched whine you hear sound like the fan - it changes pitches when it's delivering current and when it's just holding a float charge

 

[dyeguy1212]

sounds like it's working right to me. Mine never actually shut off (if you are referring to powering off), it would get fully charged to 100%, then keep a float charge around 13.1-13.3 volts.

that high pitched whine you hear sound like the fan - it changes pitches when it's delivering current and when it's just holding a float charge

Yeah I figured as much, I just didn't know if it should be shutting down when not charging or what. Seems weird that it clicks on and off every few seconds when it reaches full charge.

What about the percentage readout? Does yours say 100% and still charge for a good while after?

 

[russ010]

yea... I haven't used those chargers since I got the onboard chargers though. A buddy of mine has them right now so I don't have any batts to put them on

 

[longjohn119]

I use a Schumacher Ship N Shore charger. Its a portable unit and has a 2amp, 10amp, and 15 amp settings. I use it for my riding mower, boat, and car batteries. Worth the $50. Its mirco processor controlled, auto shut off, trickle charge if needed, plus it will tell you the current charge status level of the battery, has a diagnositc mode.

I've got a question for you and russ then, excuse the hijack. When you leave your charger on, does it say 100% for a long time before shutting off? And when it is no longer charging, does it completely shut off, or does it just switch to a different high pitched whine?

I can't decide if mine is screwed up or not. It never behaved quite right, then it experienced a flood in my basement, but it still seems to work okay, and it charges the batteries. I've just never trusted the auto shut off, because it will say 100% with 13V, and still charge for another 2 hours, still giving the same read out. When it finally does stop charging, it will alternate between the whine when its plugged in but not connected to a battery, and the charging whine, switching every 5 seconds or so.

A 100% charged battery should measure about 12.7-12.8 volts but you have to float the battery to around 13.4 volts to get a full charge. To accurately measure whether or not a battery is 100% you have to take it off the charger and let it equalize for a couple of hours or hook up a tail light bulb and let it burn for about a minute, then measure the voltage. If the charger shut off at 100% (12.7V) then the voltage would drop below that after a few minutes, the charger would start up again run for a couple of minutes and shut off again and keep repeating that cycle for quite a while before you got a fully charged battery that stays at 100%