Community Forums

LVJ58 · 01-19-2015, 12:39 PM

High Tony,

Appreciate your input..

We've had our solar system since 2005 charging 4ea 6v coach batteries and 1ea 12v chassis battery.

Continuous high charge amperage usually causes excessive battery water loss rather than the 14v charge rate.

So at 14v with a 1.5-1.8 float amperage, we haven't experienced any significant water loss with our setup.

We use the Pro-Fill system to replenish battery water which I check & add at monthly intervals where a minimal amount of water is added to the batteries.

Thanks again & Safe travels....

TQ60 · 01-19-2015, 01:35 PM

What is the rated capacity in amp hours of the battery?

This is value for C

Most batteries tollerate the following charge rates in general but dsta sheet gives specific.

1C to 2C bulk mode after deep discharge for very short period less than 1 hour.
20 to 30 amps absorption mode or after current drops down 2 to 5 hours.
0.1%C float charge

If you are floating at 1.5 amps into the battery it will consume a bit of water as you discovered.

If you had agm they would look like these...

LVJ58 · 01-19-2015, 05:58 PM

Quote:

Originally Posted by TQ60

What is the rated capacity in amp hours of the battery?

This is value for C

Most batteries tollerate the following charge rates in general but dsta sheet gives specific.

1C to 2C bulk mode after deep discharge for very short period less than 1 hour.
20 to 30 amps absorption mode or after current drops down 2 to 5 hours.
0.1%C float charge

If you are floating at 1.5 amps into the battery it will consume a bit of water as you discovered.

If you had agm they would look like these...

Our 4 6v batteries are the Interstate GC-2's rated at 225ah which suit our needs adequately as we rarely dry camp.

Stan&Jacquie · 01-19-2015, 08:23 PM

Quote:

Originally Posted by LVJ58

Our 4 6v batteries are the Interstate GC-2's rated at 225ah which suit our needs adequately as we rarely dry camp.

Many thanks folks for your many inputs. Let me clarify a few things about my system.

Batteries - 4 6v Deka wet cell batteries rated at 220 amp/hrs each

Battery Monitor - TriMetric by Bogart Engineering

Solar panels - 4 120watt panels wired with 8 gauge on roof to roof mounted junction box; wired with 6 ga welding cable from roof to solar controller and to batteries.

Solar Controller - Morningstar TriStar 45amp PWM set at 14.8 v charge rate.

Problem - Battery bank is registering 15.5 v at rest; drops to 13.8 - 14v under load. Same numbers appear on the coach's EMS meter and on my hand held volt meter. Water consumption is about 1 pt monthly.

Batteries were all new in August.

I have a call into Morningstar but they haven't responded yet.

Any additional thoughts would be most appreciated.

mcshanks · 01-19-2015, 08:45 PM

Colder temperatures increase the volt input to a battery.
I believe you are in a cold (as in Polar Express) area.
Check your charger charge chart for correct volts.

TQ60 · 01-19-2015, 09:08 PM

Where are these voltages being indicated or measured?

At the battery or on a panel someplace.

Charging voltage seems too high but you need to confirm what it should be by confirming data sheet or manufacturer.

Stan&Jacquie · 01-20-2015, 06:08 AM

I took readings at three places: the coach's Magnum EMS, the TriMetric remote meter, and right at the battery bank with my handheld voltmeter.

Perhaps cold is the issue as we have had consistently below freezing temps (into the teens at night) for the past two weeks. Highs in the mid 30's only.

MutinyGuy · 01-20-2015, 06:20 AM

Quote:

Originally Posted by Stan&Jacquie

I took readings at three places: the coach's Magnum EMS, the TriMetric remote meter, and right at the battery bank with my handheld voltmeter.

Perhaps cold is the issue as we have had consistently below freezing temps (into the teens at night) for the past two weeks. Highs in the mid 30's only.

I don't believe there is anything wrong....the below freezing temps is most likely causing your higher voltages...I have seen 15.1 from my Blue Sky solar controller in freezing temps.

BatteryPro · 01-20-2015, 06:52 AM

Hi Stan,

The main reason I joined IRV2 is the help people with their battery issues. Some of the responses you have received are in error or headed down paths that don't relate to your concern about voltage. Two people did get it right. No offense to those who were trying to help as I am sure you were sincere.

Your Morningstar charge controller comes with a temperature sensor that should attach to the battery. The purpose is to change the controller charge voltage. For each degree of temperature above 77 degrees, the voltage will be lowered to prevent over charging. As your battey gets colder, the controller will increase voltage to provide proper charging. These changes are linear.

A very cold battery may drive the voltage to the very high number you are seeing. This is normal and harmless.

Some controllers have a maximum voltage limit. This should be set to about 15.5 volts for most RV's. This is because some electronics onboard can be harmed if they see 16 volts or higher.

Larry

BatteryPro · 01-20-2015, 06:57 AM

One thing I forgot to mention is that after the controller goes to the float stage, this voltage should be much lower. The high voltage occurs during the absorption stage. If your controller is in float when you see the high voltage, something is wrong.

Larry

twinboat · 01-20-2015, 07:00 AM

Is your resting voltage with all charging sources off? If yes then you have 3 batteries in series.

What kind of load brings them down to 13.8? If it is a big ( 60-80 ) amp load, you have 3 batteries in series.

Just a crazy thought

Stan&Jacquie · 01-20-2015, 07:24 PM

Thank you all for. Putting my mind at ease.

Battery Pro: your comments were mirrored by the Morningstar rep I spoke with today.

We leave for warmth and sunshine Saturday with peace of mind!

Thank you all!

Ray,IN · 01-23-2015, 06:38 PM

Quote:

Originally Posted by BatteryPro

Hi Stan,

The main reason I joined IRV2 is the help people with their battery issues. Some of the responses you have received are in error or headed down paths that don't relate to your concern about voltage. Two people did get it right. No offense to those who were trying to help as I am sure you were sincere.

Your Morningstar charge controller comes with a temperature sensor that should attach to the battery. The purpose is to change the controller charge voltage. For each degree of temperature above 77 degrees, the voltage will be lowered to prevent over charging. As your battey gets colder, the controller will increase voltage to provide proper charging. These changes are linear.

A very cold battery may drive the voltage to the very high number you are seeing. This is normal and harmless.

Some controllers have a maximum voltage limit. This should be set to about 15.5 volts for most RV's. This is because some electronics onboard can be harmed if they see 16 volts or higher.

Larry

Yep! I had this identical situation 2 weeks ago. I asked about it on escapees.com and the response was what you stated. I was told to disconnect the battery temperature sensor from m inverter/charger. I did, and voltage at battery terminals steadily fell to 13.3VDC.