Equalization Charge v. boiling batteries - which is it?

[Vic]

So after a few trouble free years with my batteries...during which I forgot everything...pulled the camper out and it appears I had boiled the 2 6v's a bit. Left if plugged in while stored in the garage. Water was just below the plates so I added a bit of distilled and put them on my charger separately and both came up nice and slow and held a charge, so I thought I had dodged a bullet. Guilty to say this is the first time I've checked the water in a long time.

Pulled the camper outside today and with some sun my zamp ZS-30A got up to 14.6 volts and I could hear them boiling. But after doing some research, I can't figure out if this was the equalization charge or 'something bad'.

I'm fine to drop 2 new 6v's in it if needed but I'm not sure if/what the problem is. Everything seems to be functioning and holding steady in the mid 12's for voltage now that its dark, running the fridge.

But I'm concerned when the sun comes out tomorrow, we'll be boiling again.

 

[PaulT]

According to the ZS-30a manual, the equalization voltage is 15.5v for 2 hrs only once/28 days or if the battery was discharged below 10v.

Put a handheld voltmeter across the batteries if you hear it outgassing to check the voltage. If in absorption mode, the voltage should be 14.7v until current drops below 1.0 amps or 4 hours have passed.

The voltage should tell you what is going on.

Paul

 

[Old Crow]

A couple of thoughts after a quick look through the ZS-30A manual....

-- Double-check that battery type setting is correct and hasn't changed for some odd reason.

-- Check that LCD and LED indications are as expected (under multiple operating conditions).

-- Consider getting the optional temperature sensor (assuming you don't already have it). It's about $30. The manual says this about it:

"Optional external Battery temperature sensor: As an option, the unit provides a port to connect the external battery temperature sensor; if the external battery temperature sensor is connected, the unit will optimize the charging performance subjected to the battery temperature detected and also provide the battery over temperature protection, in some cases, if battery over temperature occurs, the controller will automatically stop charging."

-- If you have an infra-red temperature gun, you might use that to collect battery temperatures for a call to Zamp tech support about what you're seeing and whether a temp sensor would help.

-- Also- It may be time to consider a controller upgrade. I see the ZS-30A is a PWM model and you may want to consider going to an MPPT model and one with a temp sensor (note- if you do change, don't forget to consider polarity of your connections).
.

 

[ardvark]

Vic,

At 14+ VDC your controller is trying to float the batteries so the amperage should be greatly reduced. How many amps is the controller putting out into the batteries. Normally when batteries are fully charged and in float amp input will normally be in the area of one of less. If the output is much higher than that, at 14+ VDC the batteries will cook.

I believe you said the batteries seem to be holding at about 12+ VDC. Is that a float volts with no load or will they hold a 12+ value with a load, day a light turned on for example and your charging system off?

Ardvark

 

[JaSAn]

I am on year 6 on my Deka Penn GC2s. My experience is as they aged I needed to reduce the bulk charging voltage because of increased internal resistance (I have gone from 14.6 to 14.2 volts for bulk and absorption; float voltage is kept at 13.4V). Before I reduced the bulk charging voltage I had to add water about once a week. Now I only add water after equalizing twice a year.

Downside of reduced voltage is it takes longer to get to absorption.

My batteries resting voltage is 12.7V, SG = 1.272±.003
My controller has temperature compensation.