Is this noraml for a battery?

MURPHY55347 wrote:
I don't know if there is any such thing as normal in the rv world. Our last motorhome we could charge the batteries, hit the disconnect switch and they would stay charged for several months. Our new motorhome they go from 12.7 to 12.5 within 2 weeks with the disconnect switch off. Forest River says that is normal and state that small parasitic loads will do this. Yet they could not tell me exactly what those loads are. About the only thing you can do if so inclined is to pull individual fuses and put an ammeter in series to see which circuit is still pulling current with the switch off.

One example of parasitic load is the LP alarm; another is the entertainment system (does the display stay lit?) If you have and use a true battery disconnect, there is NO drain other than self discharge which all batteries have to some degree.

Might be time to invest in a 15 amp smart charger that will monitor the battery and adjust the charging rate in stages as it top off.

time2roll wrote:
Noco 3500 is 3.5 amps? A bit light on power unless you are 90+ percent charged. I would run it daily for 3 days or a week.

These small chargers will often give up too soon as they are made for a small motorcycle battery or just maintenance of a larger battery. Otherwise a good charger.

Otherwise put that 16v charger on for about two hours after the Noco goes green.

Yes 3.5 amp model...brand new, only used couple times. Replaced Schembler (sp) that wasn't even year old that fell apart. Auto elec place near me using them and like the long charge they give.

OK going to charge with super old Montgemery wards charger (the ones that over charges at 16 volt. But will take off in couple hours, so I don't blow it up.

rjxj wrote:

path1 wrote:
Op here.....Thanks for replies. Elec is my worst subject. I test with volt meter long after charging.

What would be the next test I should do? My cheap battery load tester, stays in the green when testing the next day.

Battery is 2 years old. It has been ran down some but not completely drained. Like maybe around 12.0

Is it possible or likely because my battery disconnect is on neg side that something is draining battery. Maybe put disconnect on positive side?

Thanks again

If you have a wet cell battery there is only one way to know what it's condition is and that is by using a hydrometer. If the battery has problems it may charge up to a high enough voltage yet the specific gravity could still be low. Checking the SG will also show differences between cells and reveal weak or dead cells. You can have a battery that is in poor condition still show a high enough voltage yet not hold it for very long and not put out for very long. It's all in the SG. Without knowing that you are just guessing.

I've got one of those hydrometers, going to find it and see what is says.

Noco 3500 is 3.5 amps? A bit light on power unless you are 90+ percent charged. I would run it daily for 3 days or a week.

These small chargers will often give up too soon as they are made for a small motorcycle battery or just maintenance of a larger battery. Otherwise a good charger.

Otherwise put that 16v charger on for about two hours after the Noco goes green.

.

time2roll wrote:
Switch on + or - is the same effect. OK to just remove a cable for testing.
I still think you are undercharged or there is a drain on the battery. Is the battery case clean?
What are you charging with and how do you determine when to stop?
If this is a WFCO you probably need two weeks minimum.

Battery is not in case.

Charging with Noco genius g3500

Stops charging when green light goes off that says 100% charged.

Also have an old charger that only puts out around 16 volts. (Reason for newer charger above) If I charge putting in 16 volts...how do I know when to disconnect the charger? Being it takes 3 or 4 hours after charging to get good reading.

Switch on + or - is the same effect. OK to just remove a cable for testing.
I still think you are undercharged or there is a drain on the battery. Is the battery case clean?
What are you charging with and how do you determine when to stop?
If this is a WFCO you probably need two weeks minimum.

"A good battery fully charged and disconnected should hold 12.65 volts for several weeks at least."

Mine do as time2roll said.

I don't know if there is any such thing as normal in the rv world. Our last motorhome we could charge the batteries, hit the disconnect switch and they would stay charged for several months. Our new motorhome they go from 12.7 to 12.5 within 2 weeks with the disconnect switch off. Forest River says that is normal and state that small parasitic loads will do this. Yet they could not tell me exactly what those loads are. About the only thing you can do if so inclined is to pull individual fuses and put an ammeter in series to see which circuit is still pulling current with the switch off.