House Batteries, Charging Rate

This is the third question related to my house battery setup.

3. My inverter/charger (2001 Trace Voyager 3,500W) specs charging rates for wet cell batteries as 14.6 vDC for the Bulk Charge and 13.4 vDC for the Float Charge. But the reading on my battery monitor indicates 15.1 vDC for Bulk and 13.9 vDC for Float (values confirmed w multimeter). So it appears that the system is charging at a rate above specs. Is this a worry?

And the inverter/charger is correctly set for Lead Acid battery type.

Next time the supposed 15V + shows check with a decent DMM at the batteries. Do not blindly believe the monitors. They usually have good meters but depending upon WHERE the reading [ie. their connection point] is taken can affect what they tell you. Where they are connected may indeed be what you say but it's what shows at the batteries that counts.

A higher charge voltage , within reason, will just require more often watering.

For sitting with solar , lowering the voltage charge and float voltage helps thru months of no attention.

GoldenDawn said:

This is the third question related to my house battery setup.

3. My inverter/charger (2001 Trace Voyager 3,500W) specs charging rates for wet cell batteries as 14.6 vDC for the Bulk Charge and 13.4 vDC for the Float Charge. But the reading on my battery monitor indicates 15.1 vDC for Bulk and 13.9 vDC for Float (values confirmed w multimeter). So it appears that the system is charging at a rate above specs. Is this a worry?

And the inverter/charger is correctly set for Lead Acid battery type.

Click to expand...

Just a data point for you. I installed a new battery monitor with digital read out. It pointed out an overcharging issue on my port alternator that I couldnt see with my installed 25 year old analog meters. The internally regulated alternator was over charging at 15.1volts. I lost an 8D that was one year old due to the issue.
Dave

Thanks for bringing that to our attention Dave.

As Celectric says, use a meter on your battery.

Currently I am off shore power and charging with the genset. The BMKs measuring at the battery say 13.6 to 14.2 volts and the inverter meter says 14.4 to 14.6 volts. The amps on the BMK battery are about 115 vs the meter at 130.

The voltages get closer together as the SOC has climbed from 78 to 90% during the past hour or so of genset charging.

BTW, a 12 year old inverter charger may well give "off spec" charging, mine started acting goofy after about 8 years and was replaced. In my experience, inverters have really improved during the past decade in all respects.

If you have confirmed the readings with a digital multi-meter, then yes, I would say you have a problem. At those rates you won't just be watering more often, you will be damaging your batteries. Can you program your charger manually....or does it just have pre-set rates? If you can program it, you could try entering a charging profile with the correct Bulk & Float charge voltages (do you have an intermediate Absorption charge rate?) & then test with DMM to see if all is correct. If you find yourself up for a new charger/inverter, try to find one with battery temperature sensing. Victron & MasterVolt are both highly recommended (no affiliation).

Take a look at the temperature vs life charts on most batt sites.

Moving the batt set out of a hot engine room may easily double the batt life.

Battery voltage checked w multimeter at batteries and battery monitors are reading correctly.

The inverter has a 3-stage charging profile. I have limited ability to adjust the profile - provide overall capacity and rate of recharge. Altering these does not appear to be changing those charging voltages associated with the three stages - they are still high.

The boat is currently hauled at the yard where this system was installed so I may be able to discuss this directly with the a installer.

I appreciate the suggestions.