Battery charging

[Tonythepony]

What charges the house batteries when plugged in to shore power?
And how would you check?

[RollaMo]

If everything is working correctly, your Converter will keep the battery charged when plugged into shore power.

[travelin texans]

Originally Posted by Tonythepony

What charges the house batteries when plugged in to shore power?
And how would you check?

To start you need a voltmeter. If you don't have one get one. Even a cheap one from Harbor Freight is better than none.
The batteries are charged by the converter either in the bottom or behind the breaker/fuse box typically near the rv door.
Start by confirming the breaker for the converter is not tripped. Don't just look at it, turn it off & back on.
Check the 2 reverse polarity 40 amp fuses on the converter are good.
Be sure, if equipped typically near the batteries, the battery disconnect is "on/connected" otherwise the converter may good but it won't be charging the batteries.
Next check the fluid levels in the battery cells topping off with distilled water if needed.
You may want to take the batteries to any local auto parts store to have them load tested, it's a free service at most.
If all the above are good disconnect shore power, disconnect the main + & - battery cables, then reconnect shore power & read the DC voltage at the disconnected battery cables, don't touch the loose cables to the batteries are anything else. You should read 13.6+ volts at those battery ends if the converter is working.
When reconnecting the cables be sure not to touch the wrong post or spark them, if so check the 40 amp fuses on the converter again to be sure they didn't blow.
Hopefully I didn't miss too much, if so others will be along to straighten it out.
It would be very helpful if you'd add a signature with the year, make & model of your rv & tow vehicle, it would show up with everything you post & would make answering your questions pertinent to your rv. Or at least add that information to every question you ask, adding to the signature is easier.

[wiredgeorge]

Short answer is that your converter takes shore power (50A) and converts it to DC voltage and a line runs to the battery to keep it charged. The voltage must be over 12V for the battery to maintain a charge and check must be done by removing the battery terminals and using a meter to measure the DC voltage on the positive side line. If you measure 13-14 VDC on the hot wire and the battery isn't charging, suggest you may need a new battery or at least take it to an autoparts store and have it load tested.

[chuckster57]

I don’t remove the battery cables. A fully charged lead acid 12V battery will read 12.7-12.8VDC. Converter will send at least 13.1VDC.

[wiredgeorge]

Originally Posted by chuckster57

I don’t remove the battery cables. A fully charged lead acid 12V battery will read 12.7-12.8VDC. Converter will send at least 13.1VDC.

That is why I suggested removing the cables to see if the converter is sending sufficient voltage to charge. If it isn't, converter suspect and would measure output at converter. If there is sufficient voltage to charge and the battery isn't charging, then off to the battery store or at least load test.

[Pull Toy]

I’m not real big on beginners disconnecting battery cables. Rather than risk sparks, or reverse polarity reconnection, just unplug shore power. You can then just read voltage positive to ground. This is close enough to give you an idea of your battery status. Then go on from there if numbers are off.

Good luck,

[DDuncan51]

Originally Posted by chuckster57

I don’t remove the battery cables. A fully charged lead acid 12V battery will read 12.7-12.8VDC. Converter will send at least 13.1VDC.

This is the way. Simple and fairly easy, depending on battery access, of course.

[MJCougler]

Team,

The only thing I will add to this thread and travelin texans reply is the definition of "To Top-off a Battery".

First, ensure your lead-acid battery has removable "caps", often two bars along the top of the battery which lift off easily using a flat blade screwdriver. WEARING SAFETY GLASSES, carefully clean the top of the battery with a water damp cloth and a clean wet small paint brush before removing the caps. Dry with a soft cotton cloth you intend to throw away.

Slowly and carefully lift each cap off by gently prying them up by lifting a little on each end, a little at a time, to remove the caps. Carefully remove any "dirt' from around the openings with the soft cloth wrapped over/around your index finger without letting anything fall into the openings.

With a small flashlight look into the cells. Look at the top of the electrolyte. You need to determine if it is flat or curved a little, looking a little like it is curved downward in the center, sort of like a bubble. It is "low' if the top of the electrolyte appears flat.

Using a NEW or clean turkey baster (not your wife's) and DISTILLED water, suck a little water into the turkey baster. Slowly and carefully, hold the turkey baster horizontal, touching the top of the battery with the end over the center of the opening to let water drip slowly into the cells. As soon as the flat electrolyte looks curved, Stop. Again, compare that look of flat vs curved as you slowly add distilled water to each cell. Again, only fill with distilled water, just to the point the water level reaches the bottom edge of the downward cylindrical opening.

Reapply the caps, and wipe away any moisture on the top of the battery.

Cleaning a battery with baking soda and water is a whole different story; Google it.

[iagtfi]

Originally Posted by travelin texans

disconnect shore power, disconnect the main + & - battery cables, then reconnect shore power & read the DC voltage at the disconnected battery cables, don't touch the loose cables to the batteries are anything else. You should read 13.6+ volts at those battery ends if the converter is working.

I'm actually having a problem with my charging (it doesn't seem to charge). When I tested this, I had around 4 volts with the shore power disconnected (we have the i400 solar package on our Carbon 338). With the shore power connected, there is no real change in the voltage across the cables, definitely not 12+ volts.

Also, none of my 12v "stuff" works without the batteries installed and shore power connected.

Is that pointing to the converter?

THANKS!!

[Mandaree]

Did you ever figure out the issue with your batteries? We are having some battery issues as well and wondered what came of your issue.

[iagtfi]

Originally Posted by Mandaree

Did you ever figure out the issue with your batteries? We are having some battery issues as well and wondered what came of your issue.

Yes, but I ended up having to take it to the dealer for the final diagnosis. They found that the converter was bad and they are replacing it now. Fortunately it is still a warranty job.

[Mandaree]

Originally Posted by iagtfi

Yes, but I ended up having to take it to the dealer for the final diagnosis. They found that the converter was bad and they are replacing it now. Fortunately it is still a warranty job.

Well that’s bittersweet. We checked ours and the voltage was 12.62 so we thought it was good but a Facebook group said if it’s less than 13 then it’s bad. Sounds like maybe that’s what we need to focus on now. Thank you for the info.