Coast Resorts Open Roads Forum: Tech Issues: New Batteries, Charger acts much differently.(update)


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landyacht318

Near a large body of water

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Posted: 01/30/12 08:12pm

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I am observing different voltages when I am plugging in my 25 amp Schumacher charger with my new batteries, compared to my old ones.

The amps really began to taper in the 14.8 range and once they fell to 4 to 5 amps, it would revert to float mode and 13.3 volts.

Now, with the new batteries, I am seeing voltages up in the 15.3 range and the amps are holding steady at 9, but will rise up 2 more amps if I turn off the 2 amps of load.

My monitor says I am 1 A/H from full.

This same thing has happened the last 3 times I plugged in the charger to these new batteries, and each time I turn off the charger before it reverts to float mode.

This charger claims to have no Equalization setting or function. There is no Temp compensation either as far as I can tell.

So is my Charger no longer to be trusted, or the much less resistance with these new batteries the reason for these high voltages and still high amperages?

* This post was edited 02/19/12 02:45am by landyacht318 *

BFL13

Victoria, BC

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Posted: 01/30/12 08:29pm

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Please remind us what the new batteries are, and what the model number/name of charger is so we can look up its specs.

2003 Chev 2500HD ExtCab, LB, 2WD, 6.0/4.10 Gas
2003 Komfort 26FS 5er (28.5 Ft-RK-10,000lb GVWR)

landyacht318

Near a large body of water

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Posted: 01/30/12 08:33pm

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2 Crown Deep Cycle Group 27. 115 a/h each

The Schumacher Charger is apparently no longer made.

But here is a link to the manual:
http://powertool.manualsonline.com/manua........g/schumacher/sc-2500a.html?idRes=7364212

I never noticed that it does have an automatic desulfation mode, but I have not seen the accompanying blinking charging light as stated in the manual.

BFL13

Victoria, BC

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Posted: 01/30/12 09:04pm

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I wouldn't worry about the battery at 15.x volts, but that is pushing the 15.4v limit for the fridge controls.

Maybe do one battery while disconnected and let the other run the rig, and let the charger do its whole thing on the one battery and see what happens if the charger will finish and go to its Float.

Then if all goes well, you can have more confidence in the charger with those batteries.

You could do a manual select equalize and see if the light flashes to know if that is working properly?

landyacht318

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Posted: 01/30/12 09:48pm

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I can't manually select the EQ function.

I wonder about my fridge's maximum voltage.

It is an AC/DC compressor fridge. Norcold de 0040 IIRC. They say is was available as a 12/24/120 volt. I don't know if the 24 volt option is a different submodel. Or if the following sticker is just a generic printed for both 12/24 dc versions, if indeed they are different.

Says maximum voltage is 32 volts, but I assume that would be on 24 volt operation.

What do you make of this sticker placed inside my fridge?

I can disconnect the fridge from the house batteries more easily than disconnecting one battery from the other, but if 32 volts is the max my fridge can handle, I should not need to.

BFL13

Victoria, BC

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Posted: 01/30/12 10:05pm

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Not a clue on the fridge label--English as a second language thing--If 32 is for 24 is it also for 12 or is there a lower max for a 12v fridge? Anyway, first find out what the charger will do if left to finish. For that until you know what will happen, IMO play it safe and disconnect the fridge if the ice cream won't melt for however long the charger will take.

Interesting set of mysteries! The charger manual said equalize is at 16v on the display, so look for that and the blinking light.

landyacht318

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Posted: 01/30/12 10:18pm

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Screw the ice cream, cheap warm beer is intolerable

Actually the fridge will still run, on AC. It switches automatically and does not require batteries for the circuit board.

Yes that label is certainly written poorly. I once called Norcold to ask about max voltages, but hung up in frustration.

I'll let the charger go the next time, and remove all delicate electronics from charging voltages and let you know. Right now it's acting as a converter, holding 13.3 volts and pushing 0.3 amps above the 2 amp electrical load.

Kind of interesting that the charger is almost following the extreme voltages and amperages listed in Crown's PDF.

http://www.crownbattery.com/PDF/Safety.First._Deep%20Cycle%20Batteries.pdf

* This post was edited 01/30/12 10:54pm by landyacht318 *

mobeewan

Hampton, Va

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Posted: 01/31/12 01:08am

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landyacht318 wrote:

Screw the ice cream, cheap warm beer is intolerable

Even though on AC power the fridge still uses 12V DC from the converter or batteries to run the control board.

PaulJ2

Northwest Oregon

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Posted: 01/31/12 01:29am

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The 15.3 volts and 9 amp indicates a battery that has sat unused for a time and is slightly sulfated. Probably will be fine after the electrolite mixes from charging. The voltage should then drop a bit.