Battery Charger Question

[sneak_e_pete]

Hi all, I need some help with something I don't understand with my battery charger for deep cycles. It has a 10A or 2A switch to charge them. I don't know which one to use. Thanks in advance for the help.

[jediangler]

I've always used the 2A setting for charging my deep cycles.

[forrest]

It depends on your battery. If it can take a 10A charge why not charge with it?

I have an AGM deep cycle.....infinite I believe as long as it stays under 125 deg F. I use 10A.

 

The best chargers are usually those multi-stage ones...CTC puts the intelligent ones on sale for about $50 a few times a year.

 

forrest

[sneak_e_pete]

How do I know if it will take a 10A charge? Thanks.

[Twocoda]

if time isnt a factor to when you need to use the battery.....put it on trickle charge ( 2 A ) setting and charge it slowly...but if you need th battery right away ..throw it on 10 A and your good to go in about an hour or so ....its much better to slow charge the battry then to power charge it ...

Edited January 2, 2009 by Twocoda

[forrest]

Ask the manufacturer/look up the specs.

 

forrest

[forrest]

if time isnt a factor to when you need to use the battery.....put it on trickle charge ( 2 A ) setting and charge it slowly...but if you need th battery right away ..throw it on 10 A and your good to go in about an hour or so ....its much better to slow charge the battry then to power charge it ...

 

A 2A "trickle" charge is too much for some batteries when left on for an extended period of time.....all you guys leaving your batteries hooked up for weeks at a time should check the specs of your battery.

 

Mine says 1.5A max trickle charge.

 

forrest

[sonny]

Twocoda nailed it...!

[Whitespinnerbait]

Charging it at 2 amps is better for the battery, mind you 10 amp is still quite a low charge and won't hurt it all

[Pigeontroller]

I've heard more opinions on this than I can count! You can charge a Battery on any amp setting, 2,6,8,10. Some Battery chargers have a 12v or 6v setting. Make sure you use the 12v setting! Unless its a 6v Battery.

[Twocoda]

2 amp is the max you will get out of a 2 amp setting ...it doesnt nessasrily mean there is a true 2 amps delivered at all times...i agree ...i get nervous when batteries are on for too long ....if the battery was completly dead .....48 hours should do ya ...if it is not completly dead ...24 hours on trickle is sufficient...any battery that needs to be charged for two weeks is called recycle.....

[Terry]

you should always charge a battery with 10 to 20 amps up to 85% full charge then it should be lowered to 2 amps

 

 

if your battery is almost out of power you could well need 100 amps, so at 2 amps per hour it will take 50 hours to charge your battery

and that's if your battery charger is in top shape and you don't have any lose from using long thin extension cords

 

but batteries like being charge with lots of amps below the point where they boil

[holdfast]

That's a good Question as I have a Nautilus Battery and Charger with trickle and 10 amp. OK, lets specify hear. I have two Batteries sitting here till Spring. Then in the summer and Fall Ill probably use one Battery per Weekend. IE, not always, but I may need a second Battery on Sunday. What is the best plan for charging as I want to keep my Batteries working as long as Possible

[Tybo]

I'll go with Terry on this one.

[Fisherman]

That's a good Question as I have a Nautilus Battery and Charger with trickle and 10 amp. OK, lets specify hear. I have two Batteries sitting here till Spring. Then in the summer and Fall Ill probably use one Battery per Weekend. IE, not always, but I may need a second Battery on Sunday. What is the best plan for charging as I want to keep my Batteries working as long as Possible

All I can say is I have a 10 year old RV battery from my trailer and another at least 5-6 years old from my boat, both still going strong. During the off season, they are both hooked up full time from late November to around mid April: http://www.batteryminders.com/batterycharg...io-p-16134.html

[PERCHER]

I say Terry has it bang on.

[forrest]

you should always charge a battery with 10 to 20 amps up to 85% full charge then it should be lowered to 2 amps

if your battery is almost out of power you could well need 100 amps, so at 2 amps per hour it will take 50 hours to charge your battery

and that's if your battery charger is in top shape and you don't have any lose from using long thin extension cords

 

but batteries like being charge with lots of amps below the point where they boil

 

One of those intellichargers will do this...thats their purpose. Watch for the sales.

 

forrest

[douG]

You can charge your battery as fast as you like, until it boils dry, or the plates warp and twist from overheating (pooched). I can't see a downside from the trickle charge, apart from the time it takes.

[Fisherman]

you should always charge a battery with 10 to 20 amps up to 85% full charge then it should be lowered to 2 amps

if your battery is almost out of power you could well need 100 amps, so at 2 amps per hour it will take 50 hours to charge your battery

and that's if your battery charger is in top shape and you don't have any lose from using long thin extension cords

 

but batteries like being charge with lots of amps below the point where they boil

After reading it again, he won't be charging anything of mine. "Batteries like being charge with lots of amps below the point where they boil" man where are you getting your info from? And don't say "I heard it from..."

[Guest steel'n'esox]

Im also with Terry on this one, although over winter I will put my batteries on a 2amp trickle to keep topped up, usually every 30 to 45 days, for about 2 hours each battery

[Terry]

it's fact

you are welcome to take 4 days to charge you batteries and I will do it my way

my point was you don't want your batteries to boil and if you drop the charging amps when your battery reaches 85% they will not

 

 

 

here are the first 3 google site cut and paste

 

 

There are up to four phases of battery charging: bulk, absorption, equalization and float. The bulk stage is where the charger current is constant and the battery voltage increases. You can give the battery whatever current it will accept not to exceed 20% of the ampere-hour rating and this will not cause overheating. The absorption phase is where the charger voltage is constant and current decreases until the battery is fully charged.

 

 

What is the best way to charge my deep cycle battery?

1. The electrical capacity of the battery charger determines how long it will take to charge your battery. In most applications, a 10-25 amp charger is recommended. First, determine the battery's state of charge using a hydrometer, voltmeter or state-of-charge indicator.

2. Check electrolyte level before charging.

 

 

 

 

Battery charging takes place in 3 basic stages: Bulk, Absorption, and Float.

 

Bulk Charge - The first stage of 3-stage battery charging. Current is sent to batteries at the maximum safe rate they will accept until voltage rises to near (80-90%) full charge level. Voltages at this stage typically range from 10.5 volts to 15 volts. There is no "correct" voltage for bulk charging, but there may be limits on the maximum current that the battery and/or wiring can take.

 

Absorption Charge: The 2nd stage of 3-stage battery charging. Voltage remains constant and current gradually tapers off as internal resistance increases during charging. It is during this stage that the charger puts out maximum voltage. Voltages at this stage are typically around 14.2 to 15.5 volts.

 

Float Charge: The 3rd stage of 3-stage battery charging. After batteries reach full charge, charging voltage is reduced to a lower level (typically 12.8 to 13.2) to reduce gassing and prolong battery life. This is often referred to as a maintenance or trickle charge, since it's main purpose is to keep an already charged battery from discharging. PWM, or "pulse width modulation" accomplishes the same thing. In PWM, the controller or charger senses tiny voltage drops in the battery and sends very short charging cycles (pulses) to the battery. This may occur several hundred times per minute. It is called "pulse width" because the width of the pulses may vary from a few microseconds to several seconds. Note that for long term float service, such as backup power systems that are seldom discharged, the float voltage should be around 13.02 to 13.20 volts.

 

Chargers: Most garage and consumer (automotive) type battery chargers are bulk charge only, and have little (if any) voltage regulation. They are fine for a quick boost to low batteries, but not to leave on for long periods. Among the regulated chargers, there are the voltage regulated ones, such as Iota Engineering and Todd, which keep a constant regulated voltage on the batteries. If these are set to the correct voltages for your batteries, they will keep the batteries charged without damage. These are sometimes called "taper charge" - as if that is a selling point. What taper charge really means is that as the battery gets charged up, the voltage goes up, so the amps out of the charger goes down. They charge OK, but a charger rated at 20 amps may only be supplying 5 amps when the batteries are 80% charged. To get around this, Statpower (and a few others?) have come out with "smart", or multi-stage chargers. These use a variable voltage that starts lower but keeps rising to keep the charging amps much more constant for faster charging.

Edited January 5, 2009 by Terry

[Guest lundboy]

Most good chargers that are the "smart type" will handle the 3 charging cycles that are required to properly charge a battery. As Terry says, at about 80% the amps are dropped from 10 (or 15) to about 2 amps until complete charge is reached and then the charger will go into a maintenance mode which will pulse low amperage to the battery when needed.

 

You can seriously damage a battery if you have an older unintelligent charger even at the 2 amp setting if you leave it attached.

 

Also a battery should be put on charge within 24 hours of discharge, or you will reduce the life of the battery.

 

Here is a PDF that explains the proper seasonal storage of deep cycle batteries (and some other tips).

 

http://www.usbattery.com/usb_images/usb_careandmaint.pdf

 

Inactivity can be extremely harmful to all lead acid batteries. If seasonal

use is anticipated, we recommend the following:

A.) Completely charge the battery before storing.

B.) Remove all electrical connections from the battery, including

series/parallel connectors.

C.) Store the battery in as cool a place as possible. However, do not

store in a location which will consistently be below 32°F. Batteries

will discharge when stored, the lower the temperature the lower

the self discharge.

D.) When not in use, boost every two months.

Edited January 5, 2009 by lundboy

[boatman]

Many correct statements have been made, but Terry is the most correct.

 

One thing that seems to be the grey area here is the intial charging rate. Yes it should be high, but not 20A for most deep cycle batteries. Starting batteries can take that sort of abuse, but not true deep cycle batteries or AGM's. The rule is that the initial charge amperage should not exceed 10-15% of the battery's total rating. Since the most common marine deep cycle batteries are 75-100 AH you should not charge at a rate greater than about 10A/per battery.

 

There is nothing wrong with maintaining a battery on trickle charge, however, it is best to use an automatic charger not a manual. This is true for both initial and maintenance charging. No more than 2A per battery for trickle charging. Left on float, a good automatic deep cycle or AGM trickle charger will charge your batteries to 100% and then shut off until the battery's charge falls below 80 or 90%.

 

Automotive chargers should not be used to charge or maintain true deep cycle or AGM batteries. You should be using marine or deep cycle battery chargers. Deep cycle batteries need the electricity to be delievered at a precise rate. Automotive chargers do not do this.

[blakewalk]

Agreed; 10 amps or higher until at least half charged, then you can just keep topping off on lower amperage for the winter- seems to work best when its at room temperature- as opposed to out in the barn