'Normal' Battery Charger Amperage Ouput?

[obsessive]

Can anyone tell me what the 'normal' amperage output from a battery charger is if just keeping the batterys 'topped off'? My maintainer/charger reads around 4 amps continously even with the boat sitting on shore power with only the stereo memory power as its sole current draw. It is a dual battery system.

4 amps just seems a bit high to me for just basically maintaining a charge...

The batteries seem good. I can pick either one and spend a long afternoon on the water with it running the fridge, stereo, water system, and two 12V fans and still start the boat with that battery with no issues. I regularly cycle between the two batteries (basically, I flip-flop batteries with the selector each time we go out).

 

[Kay Lee]

Is that with your battery switch in the "Off" position? Perhaps the ammeter on the charger is inaccurate. A fully charged, new battery should not draw more than 1 amp, and most likely half that. It could also be that your charger is not going into float mode. Put a voltmeter across the battery with the charger powered on after you're sure that the battery should be fully charged. If it reads more than 13.5 volts, it's not going into float mode and it's staying in bulk mode and that will eventually ruin your batteries.

Larry

 

[capecodcruiser]

I have a digital readout for my charger and at rest I am at maybe 1 amp. For you I would also maybe start shutting 12volt accesories off one at a time at your breaker panel and check your gauge each time to see if it changes. If you get a change you are close to finding the source of your draw.

 

[obsessive]

Is that with your battery switch in the "Off" position? Perhaps the ammeter on the charger is inaccurate. A fully charged, new battery should not draw more than 1 amp, and most likely half that. It could also be that your charger is not going into float mode. Put a voltmeter across the battery with the charger powered on after you're sure that the battery should be fully charged. If it reads more than 13.5 volts, it's not going into float mode and it's staying in bulk mode and that will eventually ruin your batteries.

Larry

I left the battery in the off position and am going to check it today/tomorrow to see if it has fully charged and is in float mode. I can also disconnect one side of it and see with my meter what the true amperage rate is.

The batteries are not new - they're four years old. While they've never indicated that they've been wearing out, I'm wondering if it's not simply just time for new ones.

 

[obsessive]

Well - I took the batteries out last night. Visibly, I didn't see any corrosion on the positive terminal of battery #1, but when I removed the terminal there was some corrosion in there. I checked the electrolyte levels, and they were about 1/4 low on each cell, so I topped them off with some distilled water, cleaned the terminals with a terminal brush, poured a little water on the case (to dilute any acid), and wiped them down.

I placed the batteries back in the boat, connected them, then fired the converter up. Now, it only reads 1-1.5A when charging, going up to just under 2 with the radio on low volume. I then rinsed the carpet and vinyl off with water (again as a precaution against the electrolyte) and dried her off. Good to go.

I did notice that one of the batteries cranks the boat over a little slower than the other and will sometimes cause the CO detector to beep (signifying a reboot or undervoltage), but it's done that for the last few years. Regardless, these batteries are four years old, so as a precaution, I'll replace them next season...

 

[Iprof]

When you poured the water on the battery to dilute the acid you are just pushing the acid into a bigger area, the water will evaporate and you will have the acid. Mix some baking soda and water and brush it on the terminals and the top of the battery that will neutralize the acid. In a battery the acid is absorbed into the plates, that's why we put distilled water back into the battery not acid when they are low on fluids.

Ken

 

[obsessive]

The batteries were not in the boat when I serviced them. I sprayed them with simple green, then rinsed them. Simple green is a base. Plus, wouldn't rinsing them off wash the acid completely off of the batteries and somewhere else (like I said - the batteries weren't in the boat, so it would have washed onto the ground). Also, as a precaution after installation, I sprayed simple green on all surfaces, followed by a good washing of the interior of the boat which drained out of the hull ports.

Regardless, I'll mix in some baking soda and spray around - never can be too safe in my opinion.

 

[Iprof]

The batteries were not in the boat when I serviced them. I sprayed them with simple green, then rinsed them. Simple green is a base. Plus, wouldn't rinsing them off wash the acid completely off of the batteries and somewhere else (like I said - the batteries weren't in the boat, so it would have washed onto the ground). Also, as a precaution after installation, I sprayed simple green on all surfaces, followed by a good washing of the interior of the boat which drained out of the hull ports.

Regardless, I'll mix in some baking soda and spray around - never can be too safe in my opinion.

Right there you can never be too safe. Let use know what happens to the baking soda and water solution when you clean up around the battery and the bilge. You might find it to thick to spray on.

Ken