Ok, just what are my house batteries up to.
They are now ten years old, and I have been watching for the first sigh of aging, but what they did today is not what I was expecting.
We are dry camping at Emma Wood state beach in California (50' x 50') of beachfront for $20 a night, Bliss except for the batteries.
Last night I noticed the voltage, which was hanging above 12.5v for a couple of days, was slightly below 12v. I started the generator and let it run for a couple of hours, during which time the charging amps dropped from 112 to 55. I shut it down and all looked ok. A couple of hours later, the inverter/charger low voltage fault light is on and the voltage is 10.4.
Ok, so I figure it's time for a new set of three 8d batteries. This morning I get up, the voltage is still at 10.4, and I run the generator for an hour of so. It has now been three hours since I shut the generator off, and the voltage is holding at 12.5 with minimal load and the inventor running.
Did I have a shorted cell that healed itself or what?
Whatever is going on, it's probably for my ten year old batteries to be replaced. Does anyone know of a good price on 8D gels in Southern California?
Tom,
Check your connections.
That was the first thing I did. They all feel solid, no play. If or when it happens again I will check the battery terminals with a voltmeter. If the voltage at the terminal is ok and there is no 2volt drop between terminal and cable, I will try switching the disconnect by the entry door off and on and feeling for heat, but for the moment I am planning to replace them sooner than later.
You might consider a load test on the batteries to see how they respond under load, but being 10 yrs old, sounds like you've gotten the full life out of them. Have a great day ---- Fritz
I definitely need to do more testing when I can.
We are dry camping, but driving back home tomorrow. When we left for dinner tonight, the voltmeters were reading 10.5v. When we got back they read 12.4. An amazing recovery. I want to leave it unplugged this weekend and try to catch it at 10.5, then measure the voltage right at the battery terminals.
Although the problem might well be other than the batteries, 10 years is long enough. I will be looking into replacing them next week.
Tom
On my coach, the genset is started by the house batteries.
At 10.4 volts, your generator should crank very slow or not at all.
Also erratic voltages over a short time is typically a connection problem, not a battery problem.
It is very unlikely that both of your batteries have shorted at the same time - one is shorted and loading down the other one. Check them seperately. One working battery will perform better than two when one is shorted. In fact a shorted battery which is left connected will result in all batteries becoming bad.
Check voltages right at the battery posts after disconnecting one of the posts on the battery you are checking. You will get a more accurate reading if you let the disconnected battery sit for an hour before checking.
Check all battery connections. I mean remove each one, look for white powder, clean the contact spots (post and clamp) with sandpaper or a rat tail file, then reconnect. Do one at a time.
I, like Barry L, have an amphour meter on each of three 8D batteries. This way I know quickly when one battery is not performing. This is important for me because I dry camp for weeks at a time in the winter, cycling my batteries more then 200 times per year. I have a hard working 12 year old Gel 8D battery which has been cycled over 2000 times.
Hi Tom,
If you are really lucky it might be a case of loose /corroded battery terminals.
I agree with what Wyatt said, especially the part about the generator not cranking with a low voltage. Maybe the problem is your voltmeter. Are the 12 volt lights normal or dim? Wait I think you have led lights, they may not get as dim as incandescent. If normal maybe everything is okay. You can go online and search for a battery price. I bought mine thru a business in Idaho, they were shipped from a Dallas distributor to Austin on a pallet. Truck had a lift gate and left them at the end of the driveway. I rented an engine hoist to R&R the batteries. Only problem with doing that; how is a defective battery warranty handled. You can sell the old batteries to a metal recycler for enough to pay for the effort. Lead should be recycled and it is the most recycled metal in the US.
y'all do realize this is a 2 year old thread, right?
I'm betting it was the voltmeter... :D
Craig
It was the batteries. No more problems ever since replacing them.
Yup. 10 year old batteries charge up real fast -- and they discharge even faster.
Although this thread is 2 years old, my 9 year old house batteries are also doing crazy things, charging up quickly, they will run 12v loads ok but turn the inverter on with any load not to good, low voltage for the auto start on the generator quit working. At Lifelines recommendation attempted to equalize them but could not get the voltage up over about 14.6 (link 2000). I think the battery's are severely sulfated, over the last year we have been plugged in most of the time they have not been worked much. Cables are all clean and tight.
Bruce,
If you can not get your inverter/charged into equalization mode with over 14.6 VDC, you might turn it off and try a cheap "automatic automotive battery charger". I use a 25 year old Sears 6 amp charger and CLOSELY monitor voltage. When voltage quits rising for half an hour (usually in the 15.5-16 VDC range), time to quit. This can take from 30 minutes to 6 hours-- all assuming you are starting with a fully charged battery bank.
Note: Always a good idea to pull the fuse for the refrigerator, salesman switch off, etc so the PC boards are not exposed to this high voltage.
9 or 10 years is a GREAT lifespan for house batteries whether you use them or not. Once they go bad, they are done. It's that easy. Low voltage can create major problems with things like starter motors so the best thing to do is replace the batteries.
When testing voltage on a freshly charged lead acid battery you may be reading just the surface charge. Try putting a load on them for a while about, 1% of capacity is good enough. Surface charge is when only the top surface of the plate has received a charge which has not penetrated all the way through the plate. Hence high voltage - low capacity.
Keith
Thanks Michelle. I was just ready to respond with where I bought my batteries in Southern California. You just saved me further typing.
Thanks Brett, I thought about that I have a charger at the shop that will put it on em. But as we are fixing to be gone by the end of March, I'm just going to replace them while I can get a good price them and have a forklift and some young guys. Going with Deka's $450.00 ea delivered to the door.