Charging Deep Cycle Batteries

[eaglemaniac]

After sitting all winter my deep cycle battery needs recharging. I was wondering what amp setting is better, 2 amp or 10 amp or a combination of the two. Thanks in advance. eman

 

[trendsetter]

Ideally you would use a smart charger that determines on it's own which amperage is best. They start off with a higher amp current then slowly taper off to a float charge when the battery is ready for it.

If you only have the choice of 2 or 10 I would use 10.

 

[Kisinana]

Check on your charger how low the batteries read, if very low charge at a high rate (your 10 amp) for a period of time say 1-2 hours and then put the batteries on at a lower rate. High current charging increases higher electrolysis across the plates in your battery ie more gassing off and if your battery does not vent properly for any reason or has low acid, you get increased heat and there is the possibility of cell warp or exploding the battery. If you have the time a slow charge is better.
Also if your charger is unregulated that is it does not shut down when the batteries are charged it too can cause battery damage even on low charge if left for an extended period say a month.

 

[fishin_magician]

After sitting all winter my deep cycle battery needs recharging. I was wondering what amp setting is better, 2 amp or 10 amp or a combination of the two. Thanks in advance. eman

10 amps. Cycle the charger "on" for 2 hours and "off" for a half hour. Then turn it "on" and repeat. 2 amps is a trickle charge and will do very little on a 24 hour charge. If you are in no hurry, put it on 2 amps and come back a day later.

As your battery gets closer to full charge it will draw less than 10 amps charging. Put it on 10 amp charge, ensure the plates are covered with water/distilled water and you should be good to go after a few hours if it isn't dead. A full charged battery should put out 12.6 to 12.8 volts.

12 hours at 10 amps should fully recharge your battery from totally dead to "full" charge.

All this stuff about " slow charge your battery" is a little bit of "BS" because if you are charging it off your alternator, most main power engine alternators charge at 40 amps minimum when running...some as high as 70-80. The regulator does the work.

How old is your battery? Charge it up fully and take it in for a load test...if it's weak, you may want to replace it now rather than chance an in season inconvenience or safety issue.

 

[eaglemaniac]

Thanks for the responses. Hey fm my battery seems to be a closed unit, it's quite a large battery compared to a car or truck and has no obvious way to open it. Could it be a sealed unit as I am concerned about heat an gases building up. I've charged for 3 hours on ten amps and then 8 hours or so on two amps. The volt meter said 1299 volts but it drops off and it still won't turn over my outboard. Iguess I should also mention I'm using a heavy duty 20 foot extention cord. I'm perplexed, maybe a load test is in order. eman

 

[Fixit]

alternators will try to maintain 14.2 volts and the amperage will vary up to the max output, depending on the load. that doesnt mean they put out 70-80 amps the whole time

a fully charged 12v lead acid battery will be 12.8V fully charged, the addtional voltage is refered to as surface charge.
it could be a maintenance free battery, hence no plugs to top off each cell

cranking voltage should never drop off below 10.6v, but i would be more suspect of a bad ground or connection somewhere remove battery clamps, wire brush them and try again

 

[Sr SQ]

Eman, from your posts it sounds like the battery was allowed to sit for a extended period of time uncharged?
This is not good for any battery deep cycle or not.
You are going to need to do a load test as you said, I have got lucky hitting the odd battery with 200 amps (start setting on my charger) for an hour or 2 so that it is bubbling and really active but have found this only lasts for a short time and you will need to top it off with distilled water prior.
Stupid "maintenance free" thats just a marketing spin on buy a new one before you should have to.......

 

[the fog ducker]

i use this , 3 bank smart charger plugged in year round ,
best investment ever , always fully charged , and shelf life to the max,,
no issues in 5 years , takes the guessing and human laziness out of the game

gd lk

http://promariner.com/products/waterproof-on-board-marine-battery-chargers/prosport-series/

fd

 

[eaglemaniac]

Thanks for your help and suggestions. I put the charger on 10 amps for 11 hours. Got up this morning to try an crank it over and there was nothing. It read 11.88 on the meter and would not crank at all. I guess it's time for new power, I was at costco today and seen a Kirkland combination deep cycle as well as cranking battery. It was slightly bigger then your normal size. What's the word on these combo batteries? Thanks eman

 

[casper5280]

Thanks for your help and suggestions. I put the charger on 10 amps for 11 hours. Got up this morning to try an crank it over and there was nothing. It read 11.88 on the meter and would not crank at all. I guess it's time for new power, I was at costco today and seen a Kirkland combination deep cycle as well as cranking battery. It was slightly bigger then your normal size. What's the word on these combo batteries? Thanks eman

Just bought the same exact battery Was told by a buddy that they are very good batteries. Only negative was that it was bigger than my battery box.. But so far no problems other then that.

 

[eaglemaniac]

Thanks casper, I have the bigger holder, so a good option for sure. There are so many good setups out there with the two battery systems, I would be happy with one as my space is limited and was curious if this would be a good alternative. eman

 

[trendsetter]

Thanks for your help and suggestions. I put the charger on 10 amps for 11 hours. Got up this morning to try an crank it over and there was nothing. It read 11.88 on the meter and would not crank at all. I guess it's time for new power, I was at costco today and seen a Kirkland combination deep cycle as well as cranking battery. It was slightly bigger then your normal size. What's the word on these combo batteries? Thanks eman

Those kirkland starting & deep cycle batteries are great. I've used them for years and never had a problem. Lots of power to start the motor and a very good reserve capacity for running electronics. Also the costco warranty is great.

 

[Seafever]

Are those Kirklands an "AGM" -type battery?

 

[fishin_magician]

Thanks for the responses. Hey fm my battery seems to be a closed unit, it's quite a large battery compared to a car or truck and has no obvious way to open it. Could it be a sealed unit as I am concerned about heat an gases building up. I've charged for 3 hours on ten amps and then 8 hours or so on two amps. The volt meter said 1299 volts but it drops off and it still won't turn over my outboard. Iguess I should also mention I'm using a heavy duty 20 foot extention cord. I'm perplexed, maybe a load test is in order. eman

Keep it open and well ventilated. Put it on 10 amps for 6 hours. If it's not cranking your outboard over after that, there's a battery issue if all else is in order. How old is the battery?

 

[fishin_magician]

Those kirkland starting & deep cycle batteries are great. I've used them for years and never had a problem. Lots of power to start the motor and a very good reserve capacity for running electronics. Also the costco warranty is great.

The warranty is the best part from Costco...the battery, not so much. Seems that my neighbours with RV's and boats were always getting exchanges....ummm...not a ringing endorsement in my books.

 

[trendsetter]

Are those Kirklands an "AGM" -type battery?

Nope, this one we are talking about is a flooded lead acid battery. Costco might have agm batteries as well but I'm not sure.

 

[trendsetter]

The warranty is the best part from Costco...the battery, not so much. Seems that my neighbours with RV's and boats were always getting exchanges....ummm...not a ringing endorsement in my books.

Man, I'm harder on batteries than most. I get them wet, dry, hot, cold, smashed around in the back of my runabout, pulled off the boat and used to power an inverter when the power goes out at my house and on and on. One thing I DO is to never leave a battery for an extended period of time without charging it. That's key to long life.

These Kirkland batteries definitely outperformed any other similarly priced bats I've had in the past (Canadian tire, interstate, wall mart etc).

 

[Chuck]

Batteries that have sat without a charge for an extended period of time will need to be conditioned. If you do this the battery will most likely come back to full charge. If you don't you will find that your batteries will charge and seem that their ok but will not hold a charge very well or for very long. Just enough charge for you to think that all is good. Get to where your going, then find out your batteries are no good. They are not something to fool around with. Because when you need them and there not useful that's not good!!
I would suggest calling the guys at Interstate Batteries. Once I learned what I have about batteries my issues have been nonexistent.

Good Luck.

 

[SpringVelocity]

Most of the batteries are made in china so it is a lot about the name brand. Many are just manufactured in same factory along side the competitors. The best batteries I have ever used in the solar industry were enerysis. That was based on engineering data through months of testing, and research. Mainly the advantage of them is that they could survive extreme discharging, and temperatures. These batteries were used in many remote offshore marine installations... So it was critical to have batteries that would not fail.

I don't have them in my boat. But I don't buy cheap canadian tire or costco batteries. Generally batteries cost me 120-150 and it worth the investment. But any battery cheap or not will not last if you don't periodically charge them. For example my batteries on my boat last from 6-7 years.

In winter I charge every month, and in summer it never sits more than a week... Summer so you know is where you can destroy a battery. They discharge rapidly with hot weather less in cold weather. Once they get below threshold voltage they will not recharge. You can do it but you would need to step charge them, and there are no guarantees.