Community Forums

Rollinghobo · 10-03-2018, 11:25 AM

That was a good read, but I dissagree with their 12.7 volts, not as the resting voltage anyway.
Maybe im losing my mind, but I always found good batterys to be at 12.5 after they settle down.
Im going to keep an open mind and do some testing. Im going to check the battery under the hood of my E450 in a while. It's been at rest since last night at around 6pm.

Rollinghobo · 10-03-2018, 12:13 PM

Just checked the battery under my hood and it showed 12.5 volts, then I called North Start Starter and asked Tim, the owner, what he thought about this, and he said that he agree's with me.
Then I called a good friend of mine who like me is also a retired mechanic, and he said he agree's with me also.

Rollinghobo · 10-03-2018, 12:28 PM

Just to clarify, what we are saying basically is that if you check your battery voltage after your vehicle sits over night, it should be at 12.5 volts.
If you charge a battery, then let it sit over night, it should also be at 12.5 volts.

twinboat · 10-03-2018, 12:51 PM

Quote:

Originally Posted by Rollinghobo

Just to clarify, what we are saying basically is that if you check your battery voltage after your vehicle sits over night, it should be at 12.5 volts.
If you charge a battery, then let it sit over night, it should also be at 12.5 volts.

Are you disconnecting the parasitic loads that every vehicle places on a battery for your overnight test ?

Jmac00 · 10-03-2018, 07:09 PM

Quote:

Originally Posted by Rollinghobo

That was a good read, but I dissagree with their 12.7 volts, not as the resting voltage anyway.
Maybe im losing my mind, but I always found good batterys to be at 12.5 after they settle down.
Im going to keep an open mind and do some testing. Im going to check the battery under the hood of my E450 in a while. It's been at rest since last night at around 6pm.

I have four 6v golf cart Lead-acid batteries powering my off-grid cabin, in a series/parallel circuit, putting out 12v they are being charged by 606 watts of PV panels on the roof through a Morningstar 45amp charge controller.

The batteries run the 12v water pump and macerator pump and 220 watts of lights. I can run everything all night and the batteries never go below 12.5v. They are usually charging at around 13.7v. they go into 'float' at 12.7.

I don't know if Golf cart batteries are any different than a Marine/RV deep cycle (other than the voltage) but mine never seem to go below 12.7 at a steady state.

Not that it makes much difference, as long as everything runs

THenne1713 · 10-04-2018, 12:05 AM

1st trick to getting the 12.7 is CLEAN TERMINALS and proper acid/ water mix levels; can get 80-90% in a couple of hours (3-4), 1-hour high charge 4.4 and 3-hr trickle 13.4; but that last 10-20% (may take) 8-24-hours. A "Smart Charger" may do it faster w/ either timer circuit or temp sensor and switches between high and trickle to keep battery temp down and prevent boiling.

THenne1713 · 10-04-2018, 12:16 AM

The trick on clean terminals can be proven if you read a battery hydrometer daily/ every few days, (say in a car); one day you will get a sharp drop in the charge, and visually see no problem UNTIL you pull terminals and find a slight white lead oxide coating that you could NOT even see w/ terminals installed; cleaning this, the charge will jump right back up the next day in normal use.

THenne1713 · 10-04-2018, 12:24 AM

BTW, in the FILEs area of this page, I have uploaded a STATE OF CHARGE chart in the ELECTRICAL folder in PDF format; TIP: Take that 12.5v battery and put on trickle for 12-24-hours, and (then) check its voltage; YES, that last 10-20% is harder/ slower to get. http://www.irv2.com/forums/downloads.php?do=cat&id=5

THenne1713 · 10-04-2018, 09:07 AM

(Typo) "1-hour high charge 4.4..." should read "14.4vdc"

Mudsock · 10-04-2018, 12:18 PM

If you don’t have a good volt meter, get one and learn to use it. You can answer most of your questions and find the cause of this type of problem easily. Turn the load on and use the volt meter with the load in place. Measure the voltage at the posts of the battery first. Then measure voltage across the load. If battery voltage is good, even 11.5, and voltage across a load is several volts lower, you have an interconnect problem. Measured voltage across interconnects should be in the millivolt range. The voltage measured across a long wire run could easily measure a few tenths of a volt under normal operating conditions with significant current. Measure the voltage drop from each battery post to the clamp on that post. It should be insignificant. If corrosion is a problem, you will see a voltage drop. The same for closed switches and relays. The critical problem is almost always found in one place. It could be in the positive or negative portion of the loop from the battery through the load and back the opposite battery terminal. Measuring voltages in a properly operating system is worth the effort to understand what normal operation looks like. A voltmeter should be high on the accessory list, right after a tire gage.

By measuring the voltage on the battery posts with and without the load turned on, you can assess the health and state of charge of the battery. Measuring post voltage close to the end of charging will allow you to evaluate the charging system functionality. Batteries operate properly and give good service life only when properly charged. Maintaining proper electrolyte levels in wet batteries is critical. A hydrometer is the best way to evaluate state of charge with a wet battery. Measure the density of each cell to see if the battery needs to be equalized. Temperature is a critical factor when charging.

Rollinghobo · 10-05-2018, 12:18 AM

Quote:

Originally Posted by Mudsock

If you don’t have a good volt meter, get one and learn to use it. You can answer most of your questions and find the cause of this type of problem easily. Turn the load on and use the volt meter with the load in place. Measure the voltage at the posts of the battery first. Then measure voltage across the load. If battery voltage is good, even 11.5, and voltage across a load is several volts lower, you have an interconnect problem. Measured voltage across interconnects should be in the millivolt range. The voltage measured across a long wire run could easily measure a few tenths of a volt under normal operating conditions with significant current. Measure the voltage drop from each battery post to the clamp on that post. It should be insignificant. If corrosion is a problem, you will see a voltage drop. The same for closed switches and relays. The critical problem is almost always found in one place. It could be in the positive or negative portion of the loop from the battery through the load and back the opposite battery terminal. Measuring voltages in a properly operating system is worth the effort to understand what normal operation looks like. A voltmeter should be high on the accessory list, right after a tire gage.

By measuring the voltage on the battery posts with and without the load turned on, you can assess the health and state of charge of the battery. Measuring post voltage close to the end of charging will allow you to evaluate the charging system functionality. Batteries operate properly and give good service life only when properly charged. Maintaining proper electrolyte levels in wet batteries is critical. A hydrometer is the best way to evaluate state of charge with a wet battery. Measure the density of each cell to see if the battery needs to be equalized. Temperature is a critical factor when charging.

I live in my rig, off grid, boondocking, so no power except the generator and alternator.
The converter will charge to 13.6 max, and the alternator charges at about 14.2.
If I did plug in somewhere and top it off it would be back to what it is now within a couple of hours at best. Been there, done that...
I would like to give my batts an equalizing charge once in a while, I simply have no place to plug my charger in, except the motorhome, and that means running the generator for hours, just to be back where im at in maybe 2 hours max.
I run ham radio gear and a 12 volt tv, so I use alot of current. I just have to charge up the batts with my gen and converter alot.
Im an advance class ham radio operator, and a retired mechanic, so I know about voltage drop testing, and I clean my battery terminals and check the electrolite levels weekly.
What I need is a better converter and solar.