Need second opinions on Battery Purchase

[deandec]

I have four 6vdc Golf Cart batteries as my house battery bank.

Shore power allows the batteries to be charged to the float stage.

Without shore power the resting voltage on the monitor is 12.6v.

The batteries will power the 12v draws like refrigerator controls, propane detector etc and show 12.6v on the monitor (matches my multimeter).

When I turn on florescent lights, the voltage drops to 12.3 v.

With the inverter on, a hair dryer will run on high only for about 30 seconds and then shuts off.

Turning the inverter off and lights off, the monitor returns to 12.6v status.

I am assuming this is the classic load test. The batteries take the charge but will not power a heavy load. Therefore they need to be replaced.

Any second opinions out there?

[Go Dawgs]

Hair dryers are a large draw on batteries. Your numbers look good to me.

[Ramblin]

Hair dryers are typically ~1500W. I imagine you are overloading your inverter unless you have one that can handle that load.

[nytrorcr]

Originally Posted by Ramblin

Hair dryers are typically ~1500W. I imagine you are overloading your inverter unless you have one that can handle that load.

I think you battery #'s look good also, inverter may be just alittle small for the job.

[deandec]

Thanks for the ideas guys. A bit of clarification on my part would have helped the analysis with hindsight. My apologies for not including the below info.

The Inverter is a 2500W Freedom which has run the hair dryer continuously as well as the microwave, electric coffee pot, and electric heaters in the past, although not all at once. So, unless the inverter is broken or the batteries are bad, the hair dryer should run much longer than 30 seconds.

[Dunner]

Maybe the hair dryer is going bad. I think they have thermal relays that kick off if over-loaded. It may just be getting tired.

[jdr159]

Two thoughts: try one of the other devices to see if they 'drop out' quickly or take your RV to an advanced auto type store and have them test your batterieS. I would then make a decision on what the battery load tester said. Good luck.

[TQ60]

Monitor bat voltage during test.

I suspect drop below 10 volts and inverter shuts down to protect batteries.

Likely bad cell or bank.

Sulfated batteries do this, hydrometer reads normal, but effective plate surface area small.

Imagine starting engine with a lawnmower battery or tripla a cells,

[deandec]

It is nice to have great minds focused on this issue of mine. Lots of alternatives to explore.

The hair dryer was the implement I chose to demonstrate my issue and it works fine when plenty of juice is available. Furnace and microwave also will not operate with the inverted batteries.

I have read that the auto stores are not equipped to load test deep storage batteries like Golf Cart batteries. That is why I presented the above event as a possible load test.

I have had no indications that the inverter is malfunctioning, but the batteries will have died in less than 3 years, which is unusual in my experience.

I did equalize the batteries every six months and as recently as four months ago. The hydrometer did read normal after a full charge event, but the hair dryer type event seems to say the batteries are toast.

Thanks to all for the comments forcing me to think through the problem. I guess I will have to spring for $400 worth of house batteries to fix the issue before our next dry camping event.

[vsheetz]

Brand/model of the batteries, how old? I bought a break-down tester for ~$60 that allowed me to see that I had 1 of 4 Trogan 105 batteries failing. They were all ~10 years old so replaced all four.

[deandec]

These are Costco Golf Cart batteries which replaced my previous six year old Trojans. They are just at 3 years old.

[Muddypaws]

Are you sure your refrigerator or some other power hungey AC device is not drawing current? Normally the refer AC would not be wired to the converter, but the icemaker might be. So if the plugs got swapped somehow....... Just thinking out loud.

I've always used Kirkland/Costco batteries in all of my cars & RV's and never had one fail on me.

[Gorlininc]

I wouldn't turn on the hair dryer anymore when your not plugged it to shore power or the generator on. That's a draw of over 100 amps on the batteries. I'm surprised they lasted 30 seconds.
I changed all my fluorescent bulbs to LEDs so there's no drop now. Your batteries are probably fine. I would load check them if you are concerned.

[Pullin' Chocks]

We had a loose battery cable and experienced the same behavior. We tightened the cable and the performance improved significantly. Later determined one of our four T105s was dead. Replaced that and battery/inverter performance is what one would expect now. Check battery cable connections. :-)