Community Forums

LDM Dave · 08-12-2022, 11:25 PM

Hi all.

We were recently at a slightly rustic private campground with 30 amp service only in our 33’ gas Allegro Open Road with 4 in line 6 volt batteries - and a voltage conditioner connected between the service post and the RV. After being there a couple of days I was inside and purely by fluke noticed that I was sitting at 14.4 volts rather than the 13.5 that I had been up until then. No idea how long … possibly minutes, possibly hours. When I lifted the step tread to see if I had boiled over, I hadn’t, but I could hear a slight bubbling. I threw the breaker on the service post, waited a minute, and turned it back on with no further such incidents the remaining two days we were there .. stayed at 13.5 and without any apparent problem with the things running on electricity.
Wondering if anyone would have thoughts or comments as to what might have happened there. I did Google it and actually saw the specific 14.4 figure come up with regularity, but the technical aspect of most of it was above my head.
Any input would be appreciated!

MrMark52 · 08-13-2022, 03:50 AM

That you were plugged in to a 30 amp service doesn’t have any real bearing on what you experienced (I would be more concerned if it were a 50 amp service that was miswired).

Without knowing the details of your system and what 12volt usage you were experiencing - I would suggest that you check your batteries to insure plenty of water.

Most of the newer microcontroller based chargers have multiple modes of battery charging operation that all depend on battery usage - and the output can fluctuate between 13.6 and 14.4/14.6 volts.

Sweetbriar · 08-13-2022, 04:33 AM

You coach has a multi stage converter/charger what will vary the volts to help extend the battery life. A multi stage charger will cycle thru various voltage levels for the Bulk Stage, Absorption Stage, Float Stage and if you have a four stage converter an Equalization Stage. You probably just happened to see the volts during or near the end of the absorption stage which can be in excess of 14VDC.

This cycle will happen without regard to 120VAC amp capacity you have access to.

twinboat · 08-13-2022, 06:24 AM

The 14.+volt mode happens every 22 hours or something like that with my 4 stage converter /charger.

It boosts the volts to stir up the electrolyte in flooded batteries, so hearing a bit of bubbling is good.

THenne1713 · 08-14-2022, 12:23 AM

On a multi-stage charger, the float to higher voltage for short periods of Boil is to PREVENT cell "sulfation", from what I understand... WHERE battery looks charged, but goes dead quickly... a condition that kills a battery

Mark_K5LXP · 08-14-2022, 07:34 AM

Sitting at the absorb voltage of 14.4V for 2 to 4 hours is not only normal, but required to achieve a full charge. "Smarter" chargers adjust the absorb time based on current but most are time based. It can be a bit disconcerting to hear the batteries gurgling and blurping but for the short time they do this, it's promoting an even, full charge and well distributed electrolyte.

Mark B.
Albuquerque, NM

LDM Dave · 08-19-2022, 01:28 PM

Hi again all - and thx for all the feedback .. I learnt quite a bit, including that it was ok when my batteries were getting charged to 14.4 V. Shouldn’t have interrupted the process. The only nagging thought left in my mind is why I haven’t noticed this before. We’ve spent 11 six month winters away in 3 different smaller class As, 3 or 4 in the current one, and haven’t ever noticed that before. I would think that the odds are quite low that it has been happening all along and I just never happened to glance at the read out at the right time, but ….

MrMark52 · 08-19-2022, 01:39 PM

You don’t say what year your coach is, or more importantly - the make and model number of convertor in your coach.

As I mentioned previously - you need to make sure your convertor isn’t one of the old linear design types. They WILL boil your batteries. Simple to change to one of the newer microcontroller designs as there are 2-3 different manufacturers (I like Progressive Dynamics myself) of “drop-in” replacements.

Ray,IN · 08-19-2022, 05:32 PM

FWIW, if your 6V batteries are wired correctly, that is not associated with the bulk charge rate you saw.
Do you have a battery temperature sensor? If so, unplug it and observe charge voltage when it should be at float 13.3.
My sensor went bad, float was 13.8-14.2; I unplugged it and float voltage returned to normal.

THenne1713 · 08-19-2022, 10:38 PM

Cold weather requires a HIGHER charge voltage, and desulfonate cycle, if programmed runs a higher voltage/ temp for short period to clear cell plates, I read?