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Author Topic: Charging NEW gelcel  (Read 280 times)
KA5ZCB
Member

Posts: 16




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« on: February 27, 2006, 11:17:54 PM »

I received a NEW 12V 5AH Sealed-Lead-Acid-Battery
and went to HarborFreight and got a charger (#93258/below) that
someone here mentioned worked well.
(it was on sale last week for $10, too)

How long should it take to charge a NEW battery ?
Mine has been connected/charging for 24+ hours
and the  CHARGE-LED is still burning.

Also, the unit HUMS.  Its  a little larger than a Kitchen-Match-Box
and is expectly warm-to-touch, but not HOT.

http://www.HarborFreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93258

thanks.
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N4CR
Member

Posts: 1701




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« Reply #1 on: February 27, 2006, 11:32:13 PM »

A 5AH battery should take:

.5 amp for around 10 hours or
.25 amp for around 20 hours, etc.

What is the min and max charging rate for the charger? Do you have an ammeter to test the current charge rate?

I generally find that small SLA's are charged in a day or less and then the charger switches from bulk to float for maintenance.
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73 de N4CR, Phil

Never believe an atom. They make up everything.
G4AON
Member

Posts: 545




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« Reply #2 on: February 28, 2006, 03:32:29 AM »

Gelcells are supplied fully charged. I would expect a charger to switch to trickle charge after an hour or so when using it with a new battery for the first time. The price you quote for a charger seems pretty cheap, you need to check the voltage across the battery.

I usually charge them from a current limited home made power supply, set to 13.8 Volts. When the current drops to 200 - 400 mA from an original 2 Amps, it's time to turn off the charger.

Dave
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AD5X
Member

Posts: 1437




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« Reply #3 on: February 28, 2006, 04:39:01 AM »

My Harbor Freight charger has two LEDs.  One that shows when it is charging, and one that shows when it is not.  After the battery is charged, you'll see it cycle between these once in a while.  It's been a while since I checked the voltages, but it seems that it charges until you get to about 14.4 volts.  Then it switches off but lights the "charged" LED.  When the voltage drops to around 13V (I think), it switches on again.

Harbor Freight also has a trickle-type charger that never shuts off.  It only has one LED.  Any chance you got this one?

Phil - AD5X
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K5LXP
Member

Posts: 4536


WWW

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« Reply #4 on: February 28, 2006, 06:26:51 AM »

G4AON is right, gel cells should be pretty close to 100% if they're new and haven't been sitting on a shelf for a couple years. I too suspect you have a battery 'maintainer', not a charger. These chargers don't supply enough current to charge a depleted battery (in any reasonable amount of time). Spend the bucks and get a real two or three stage charger built for gel cells (not motorcycle or automotive batteries). I use a PowerSonic 124000 charger for my gel cells. Some of my gels are over 6 years old and still near full capacity. Rechargeable batteries usually don't die, they're murdered, through improper charging or storage. Buy the right charger and you'll never have to worry about it.

Mark K5LXP
Albuquerque, NM
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WA9SVD
Member

Posts: 2198




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« Reply #5 on: February 28, 2006, 10:41:43 AM »

I would question the "1.5Amp" claim, but the item is described as a trickle charger,

QUITE:  "Auto on/off trickle charger keeps 12 volt batteries fully charged without overcharging. Also great for maintaining batteries while in storage."

Unquote.

    It will do a good job of maintaining a battery once charged, but isn't very good for "charging" all but the smallest batteries.  Either keep it as a "maintainer" for other batteries (it wasn't THAT expensive on sale, and you can probably find a use for it) or exchange it for a full-function charger.
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AA4PB
Member

Posts: 13032




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« Reply #6 on: February 28, 2006, 11:09:08 AM »

His battery is only 5AH. Actually a 1.5A charger is a little big to bulk charge a 5AH SLA battery. SLAs normally have a maximum bulk charge rate around 0.15C which would be only 750mA for a 5AH battery.

Once the battery is charged, the charger should switch to a constant voltage of 13.8V. At that voltage the battery will draw only the current it needs to stay up with the self discharge rate.

I expect they are calling it a "trickle" charger because it was intended for use on a much larger battery. On a 70AH battery, 1.5A is a trickle charge.
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N6AJR
Member

Posts: 9927




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« Reply #7 on: February 28, 2006, 12:55:57 PM »

I use a 3 stage charger for all of my beatteries that are not connected to solar.

you will see a 3rd wire  usually yellow that also goes to the + post.  these have a hi current ( mine is 1 amp) at a lower voltage(13.7 ??) , then the do a high voltage , low current topper (14,6 volts??) then drop to a maintainer charge ( 12.7 v at low current??)

I may be off on the voltages but it works like that.  Mine id fro A & A engineering, about $50 for an assembled one.

all 3 stage cghargers have 3 wires, pos, neg and sense.
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KC2MMI
Member

Posts: 623




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« Reply #8 on: March 01, 2006, 06:04:19 PM »

<I received a NEW 12V 5AH Sealed-Lead-Acid-Battery >

You may want to check with the maker. Some of those are gel batteries, while others are now AGM batteries. The charging characteristics and everything else about the two are slightly different. To get the best life from it, you'd need to confirm which one it is. Both are "Sealed Lead Acid" aka SLA or SLA/VR (valve regulated) types, but they are not the same thing.

Due to charging losses, recharging any battery generally takes roughly 120% of the time that you'd expect based on "just" putting the capacity back in, i.e. you can expect about a 20% charging loss.

Mark, I don't know how you get full capacity of GEL cells after 6 years. Anything I've seen from the makers indicates that even on a float charge, they won't make it half that long without substantial losses, no matter how respectfully you treat them.
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