Batteries buzz when charging?

Mike at Energy Commission

I have 2- 6v deep cycle batteries as my battery bank, all has been well for the last couple of months since I bought them. Today they decided to hum a buzz while charging? I assume this is due to some resistance in the batteries, probably bad news. Anyone know what causes this? how can I test for serious problems?

Blackcherry04

Re: Batteries buzz when charging?

Yeah, get a hydrometer and check the SG's, when fully charged and rested 2-3 hours they should be 1.265 on the SG scale. If they are low you have to Equalize ( 15-15.5 V ) them for a hour at a time until the SG's stop rising. Keep a eye on the temperatures and keep them below 115-120 F by stopping and starting the EQ. Maybe the buzzing sounding is just the gassing your hearing. You didn't say what voltage they were at, sometimes you'll hear them in full bloom gassing, I have a set of GC-2's HDX Interstates and they are the loudest I'v ever heard.

BB.

Re: Batteries buzz when charging?

You may get buzzing from an AC battery charger or a MPPT / PWM battery charger (the solar battery chargers have quite a wide range in PWM frequencies--From a few times a second to 1,000's of times a second--which can cause the plates to vibrate a bit).

As BC4 says, check the specific gravity and the cell (or battery) voltages and see if there is anything "odd" going on.

-Bill

Mike at Energy Commission

Re: Batteries buzz when charging?

ah ha! it was the connector cable that connects the 2 batteries it was very loose. Tightened it up, all is well, everything is working well this little kit powers my refrigerator, laptop and a TV all evening.

Blackcherry04

Re: Batteries buzz when charging?

Mike at Energy Commission wrote: »

ah ha! it was the connector cable that connects the 2 batteries it was very loose. Tightened it up, all is well, everything is working well this little kit powers my refrigerator, laptop and a TV all evening.

Wow, I blew that wide open. I guess it was resistance, but a different kind. Glad you found it, that can cause a lot of heat if the current is high enough it'll melt the lead post.

icarus

Re: Batteries buzz when charging?

I have several ferrites in my battery cables to reduce radio interference. Occasionaly I will get a big buzz from near my battery bank, and I think that either the inverter or the CC are in trouble. When I trace the trouble it turns out that the ferrites are vibrating on the wire. Moving them a mm or two and it stops. It happens so rarely I often forget the solution when I start the trouble shooting.

Tony