Charging Deep Cycle Battery - ???

[tnvolgrad]

Am I missing something? I hooked up the charger to the cranking battery and it charged fine, but when I connect it to the deep cycle battery it keeps telling me to connect the cables. The cables are cleary on and the charger works fine - any special way that the deep cycle has to be charged? I noticed if I connect one cable on the cranking battery and one on the deep cycle it begins charging?

Before I catch something on fire or fry something figured I would put it for all the mechanically inclined.
Any help would be appreciated.

[chpthril]

Whats the amp rating/output of your charger? Sounds like the deep-cycle is completely discharged. If so and the boat has been out side in the cold temps, then dont waist the electricity to try to charge, just replace it.

[tnvolgrad]

It is a 25 Amp smart charge with a 75 amp engine start feature - black & decker special.

[chpthril]

Kick it on the 75A for about 5 minuts and see if it starts to take a charge.

[tnvolgrad]

No luck - it will not kick on unless it recognizes the battery. Given it is dead - sounds like a new one is due. At least the cranking battery is good. I assume a battery is good for 3-4 years in the marine world. Given my boat is a 2008 that means the battery was probably manufactured in 2007.

[chpthril]

No luck - it will not kick on unless it recognizes the battery. Given it is dead - sounds like a new one is due. At least the cranking battery is good. I assume a battery is good for 3-4 years in the marine world. Given my boat is a 2008 that means the battery was probably manufactured in 2007.

Discharged batteries usually don't recover from a freezing, regardless of age, but yes, anything past 3 years is borrowed time for a battery.

Try connecting the batteries with jumper cables and connecting the charger to the starting battery

[Ewok]

Does the charger have different modes for different types of batteries? Mine does. Also check to see if it has a manual setting. I thought I had a dead deep cycle battery cause my automatic cycle charger wouldn't finish the charge. I had to get a full manual charger (10a is what I bought) and let it sit for a over 10 hours. After it got some juice I was able to use the automatic charger to finish the charge. It just took a long time to come back to life. Before I got the my new manual charger I did buy a battery thinking the old battery was dead. Now I use the old deep cycle as a spare battery in the boat for myself or others if they need a jump.

[jwanck11]

My deep cycle sat for over a year and was discharged. The theories are as wast as diets; however, I like to charge DC batts at 2 amps and let sit overnight.

It sounds like a manual charger is a way to go at least to get some juice in the batt and then you can use the auto charger. At least that would be less expensive than getting a new DC.

[talltigeguy]

Put a voltmeter on it and find out how far discharged it is.

I had a 12 volt motorcycle battery reading 1.5 volts last week...not a doubt about needing to be replaced there.

[tigecanuck]

Kick it on the 75A for about 5 minuts and see if it starts to take a charge.

The smart-chargers often do not want to charge a completely dead battery. Try an old school charger before you send the battery to the recycler. I don't buy the smart chargers any more for our boat showroom for that reason.

[chpthril]

The smart-chargers often do not want to charge a completely dead battery. Try an old school charger before you send the battery to the recycler. I don't buy the smart chargers any more for our boat showroom for that reason.

Thats why I suggested the 75A start mode, that was the best option to try and get the battery to begin to take a charge. Other then that, connecting them in parallel with jumper cables will allow the starting battery to equalize with the deep-cycle. This just might get enough voltage into it in order for the charger to recognize that its hook up and charge.

I have a jump-box that does the same thing....wont work unless it senses some voltage.

[tnvolgrad]

I appreciate all the feedback. My neighbor has a manual trickle charger that I will try that approach before buying a new one.

I did try the jumper method and it made a wierd noise like something was running. The red power block was swithched to off so I am not sure what mechincally could of been running - when in doubt shut it off.

[chpthril]

I appreciate all the feedback. My neighbor has a manual trickle charger that I will try that approach before buying a new one.

I did try the jumper method and it made a wierd noise like something was running. The red power block was swithched to off so I am not sure what mechincally could of been running - when in doubt shut it off.

Sounds like the bilge or blower tried to run. That would explain why the battery is completely dead.....a DC motor will just keep running until there is no juice left.

The trickle charger may work, but typically a heavily depleted battery will need about 15-20A or more just to get it charging. A typical trickle may do 2-5 amps.

[docskj]

I had the same problem until I changed the settings on my Sears charger to "deep cycle". Then it charged just fine. I didn't even know I had that setting until then.

[mls6722]

Charging with the battery connected?

so, I believe my deep cycle battery is dead or dying. Nothing runs with the ignition in ACC. A 2007 which I test drove did the same thing. Both had the green Interstate batteries, so I assume that was original equipment which means they are due for replacement.

My question / comment is: It looks like a pita to remove or disconnect these batteries but I believe there may be a risk to my electronics to hook up a charger with the batteries wired into the boat. Any advice or comment?