Battery charging issue resolved, perhaps

The first thing I would do is make sure that the converter is working or not. Make sure that 115vac is going into the converter and it is on, warm, buzzing, whatever. Then check the output right at the converter output terminals. You should see about 13.8 with an older single stage converter. If not, your converter is toast. If you have good voltage at the output terminals, the converter is working and you have a wiring/ground connection problem between the converter and the batteries.

i have the same rv just 21', when plugged in battery disconnect has to be off in order to charge battery- once charged turn on to storage mode to maintain battery life and not over charge. if not chargeing check the in line fuse dwn by battery- i had to replace mine to get battery to charge when plugged in. problem im having now is - cant get power to battery or coach when chasis is running.

rich85704 wrote:
I spent some time with the rig this afternoon. Even bought a new digital multimeter to replace the Radio Shack cheapie I was using. I found a few wires which might be considered loose in the battery area, tightened them, and took the following readings:

When I arrived, about a day after giving it a full charge at home, I took a reading at the battery terminals with the battery connected to the rig. 12.3VDC in either position of the BD switch.

Disconnected battery from rig. Same reading at battery terminals: 12.3VDC

Turned on the generator, and measured its output at 128VAC

At the battery, with generator running, 12.4VDC, same as with no generator/converter input.

Disconnected the battery from the rig and measured voltage on the leads: 8.4VDC; this presumably is the output of the converter.

So I can't replicate the scary high 15VDC readings, which may mean I'm less likely to boil the battery. But the 8.4VDC out of the converter is concerning, right?

I'm thinking this suggests a new converter. Any other tests I should do before I go that route?

Rich

I would say your converter is not charging for some reason, although you said it is running your 12v systems, which suggest it should be charging. You might have wiring issues between the converter and battery, or issues with the disconnect switch or something else. Measure the voltage at the converter and let us know.

Whatever it is, your battery is toast. 12.3 fully charged means it's been ruined. It will suffice for testing but it has no capacity.

You 99 Coachman probably has old Magatek converter which is designed to put out constant 13.6 volts .. they tend to deplete battery water and are often called a battery eater. Since you haven't got a reading yet which would be called "normal" I would replace the converter - not expensive and lots of DIY examples on the web.

I spent some time with the rig this afternoon. Even bought a new digital multimeter to replace the Radio Shack cheapie I was using. I found a few wires which might be considered loose in the battery area, tightened them, and took the following readings:

When I arrived, about a day after giving it a full charge at home, I took a reading at the battery terminals with the battery connected to the rig. 12.3VDC in either position of the BD switch.

Disconnected battery from rig. Same reading at battery terminals: 12.3VDC

Turned on the generator, and measured its output at 128VAC

At the battery, with generator running, 12.4VDC, same as with no generator/converter input.

Disconnected the battery from the rig and measured voltage on the leads: 8.4VDC; this presumably is the output of the converter.

So I can't replicate the scary high 15VDC readings, which may mean I'm less likely to boil the battery. But the 8.4VDC out of the converter is concerning, right?

I'm thinking this suggests a new converter. Any other tests I should do before I go that route?

Rich

rich85704 wrote:
1. Measurements -- I reported "With external power and the battery disconnect switch in "use" position, there's 7.8V coming out of the converter into the battery. Same using generator power.In the "store" position, there's 15.7V. " These measurements are taken at the battery position, with the cables disconnected from the battery. This, I thought, would show me the output from the converter. Yes?

Are those measurements at the battery or the converter? Because no matter how messed up the converter might be, you should not be seeing 15.7v at the battery in the Store position. Now if it is at the converter, then maybe only the converter is bad.

2. When the Battery Disconnect switch ( Intellitec BD) js in the "store" position, the electric step still functions. All other 12V systems that I can find are off. Normal?

The step is probably wired to the chassis side, which is the best practice IMO. But no, if the converter is running, it should be providing the 12v for those other systems while the battery is disconnected via the switch.

4. I'm satisfied that the automatic cutover from shore power to generator is working. Is there any reason why I can't test this using generator power. I can do that in the storage yard, as opposed to driving the thing to a friend's house.

Yes, the generator power will be fine as a replacement for shore power.

rich85704 wrote:
I think I'm headed for a Progressive Dynamics PD9245 converter. They have factory-reconditioned units with a 1-year warrantee. KSG, given your problems with them would you buy again?

They examined the unit and agreed it was defective .. replaced free of charge. Wasn't happy about ruining batteries and sensitive stuff but S*** happens and replacement has worked fine.

I think I'm headed for a Progressive Dynamics PD9245 converter. They have factory-reconditioned units with a 1-year warrantee. KSG, given your problems with them would you buy again?

Again, thanks, all!

Testing at the battery is a simple way of testing converter .. might lose something because of distance/wire gauge but easy way to determine whether converter is operating. In your case the high readings would indicate that your converter needs replacing. I had similar problem with Progressive Dynamics converter and high voltage required me to replace expensive controllers etc.

Did someone say "bad converter"? If not, they should have. When plugged in or on generator, depending on make of converter, you should be seeing 13.6v to 14.8v, always. The position of the battery storage switch should not matter.