Battery Not Charging: Troubleshooting Tips

One of the most common questions we get on our social media sites is low batteries. People having problems with them, holding a charge, lasting very long. Now, we've got a very interesting question that just came in on batteries that says, "I have a battery problem. "Had the engine and coach batteries on trickle charger, usually a two amp battery minder", oh excuse me, "battery tender and checked them before an upcoming trip. "Both batteries were down to two volts." That's pretty concerning right there. "There was an event at our property "that caused an electrical problem. "After charging and installing the batteries "I noticed I was getting no juice at the coach battery. "The converter shows 13 volts. "Traced the converter to battery line, "to box, to capacitor looking devices. "Can you help diagnosis? "I have 13 volts at the box, zero volts at the battery." So, first thing is we've got a typical battery set up here on a Monaco. This happens to be a 1996. It's got the start batteries and the house batteries. What a lot of people don't realize is when you are hooked up and just letting them charge on a normal charger, you're not conditioning the batteries properly. They need to do a multi-stage charge. So, you do like a 16 volt charge, it boils these batteries up and breaks up the sulfur. Then it goes into a float and an equalizing charge. And unless you've got one of the very large 2000 watt inverters with that multistage, by leaving it plugged in you're just simply letting the batteries drain down to 10.5 and then go get a hard charge and that'll bring them up to 12.5 and that's not gonna condition them. By just putting a two amp battery tender on it, same thing. You're gonna get sulfation. So, a couple of things to look at. First of all, this setup here kind of concerns me a little bit because we have our engine battery right here the chassis battery. I've noticed on our terminals here, that on this side of the terminal, it started to deteriorate. And we only got about an eighth of an inch of metal touching that. And this rig has had a lot of problems with batteries. They've replaced probably about five different times and mostly because they leave it in a storage facility just plugged in. Now, the second thing that's a little interesting about this is this is the tray for the house batteries. And when this was brand new, it would've come with four Trojan six volt batteries, hooked in series and then to parallel, meaning positive to negative on the first two banks and that would give me 12 volts of power, then positive to negative on the second battery bank and then positive to positive so that the two 12 banks would create a 12 volt system but with a lot of amp hours. Now, the concerning part about this one is I see that here are the traditional cables that came in with the spade, because most of your deep cycle batteries are going to have the wing nut or some type of fastener like that. Not the posts. This battery right here was just put in within the last probably two, three months. It has 1000 cold cranking amps. Now, a house battery a deep cycle battery, does not rate by cold cranking amps. You don't want that hard charge to start an engine. You want a deep cycle to be able to last longer. You're gonna look for amp hours. A group 24 is gonna have about 110, a group 27 so forth in the different groups in the more amp hours. And I think what happened with this one is they had problems with it. They went to an interstate battery, which not really familiar with motor homes and travel trailers, and it looks like they got too cold cranking amp batteries in this down for house batteries. And then they just put an adapter over the years and popped it in. Cold cranking amps or start batteries are not designed to be drained and cycled back. House batteries deep cycle are designed for that. So, if you do this, you drain it down. You can just keep letting that happen. Eventually, they're gonna go bad. Probably why they were having some problems with this one. Now, in the question that we had here, again, the two amp battery, the first thing I would check is take the battery somewhere, do a multi-stage charge. The only way you can tell the capacity of your batteries is to connect them to a 25 amp draw and see how long they last. I would bet they're sulfated. I would bet that they have very little capacity but now if it's showing zero in there you also have what's called a momentary start. It's a solenoid and he mentioned that in the question that there was two solenoids inside of it. When you're driving down the road in a typical motor home like this, and a travel trailer won't have this, but motor homes will have a momentary switch. So, when I'm driving down the road that engine alternator goes through that solenoid and charges my house batteries. If I'm at a campground and for some reason I leave my engine battery on, radio playing, whatever, that engine battery drains down. I can push that momentary switch and jumpstart my house batteries to my engine battery. It's through that solenoid though. So, if you had an electrical problem at the facility you have 13 volts coming out of your charger which he claimed to have with his meter, coming out of your distribution center or your converter but you have zero at the batteries, then I would say that you probably have those solenoid have shorted out. And usually they're located right in the same compartment. Now, these we've got a couple of disconnects under here. The solenoid is inside hidden, but a lot of your, a lot of your motor homes will have it right in the stepwell, right next to that. So, with that you're gonna have to get that solenoid checked. If it's not coming to the other side you probably need to replace it.