Community Forums

Full.Monte · 07-21-2019, 11:26 PM

Hi Guys,

I have a Progressive Dynamics 9260 converter. It doesn't seem to be charging my two 6V golf cart batteries wired in series. When I turn on the generator, I measure 13.7V across the output of the 9260, but at the battery, I was getting 12.4 volts and no apparent charging activity. When I start the RV engine, the batteries are charging fine, and the voltage at the battery terminals is over 14 volts. When I called tech support at Progressive Dynamics, the nice guy there said that my automatic resetting cable protection device was likely shot. I did notice one between the two batteries ( sort of a bigger round bulge in the cable near the terminal in the jumper between the batteries). I wondered if the cable had gotten the ends switched when the new batteries were put in. I switched the cable ends, and now I'm getting 12.7 v across the two batteries when I turn on the generator. I'm wondering if anyone has had a similar experience. If the 9260 is putting out 13.7 v, why am I getting only 12.7 v at the batteries in series? 12.7 seems like an improvement, but why isn't it 13.7 v? Thanks!

Sbrownstein · 07-22-2019, 03:22 AM

You are going to have to chase the PD lines from the converter to the batteries. On many coaches the converter feeds the DC power panel and from there goes through the disconnect switch to the batteries.

With the converter running, what is the voltage on your DC power panel?

Careful switching cables...can be costly.

Check the grounds on the converter and on the lower 6 volt battery. You can also put the meter between the chassis and the battery negative to see if you can find your missing voltage. Something is dropping it and it takes a bad connection and a little current to do that.

**Spdracr39** · 07-22-2019, 05:44 AM

Has it ever worked properly ? If the cables are undersized and the converter is located a good distance from the batteries the voltage drop could be significant. As stated above a loose connection somewhere in between could be an issue. I don't see how old your rig is but corrosion inside the cables can also be an issue.

bigchick · 07-22-2019, 06:43 AM

my thoughts are that the 12.4 volts you got at the battery was the battery voltage only without any voltage from the converter. you could confirm this by measuring voltage at the batteries without the generator and then again with the generator running.

if both readings are the same you are not getting power from the converter. first places to look would be the battery disconnect switch and the resettable 12 circuit breaker. these will be in the power path from the converter to the battery. or of course a loose connection.

if the voltage measurements at the battery change between the with generator on or off readings it is probable that you have a bad / loose / corroded cable or connection somewhere on the power path. this will take inspection and correction.

the higher reading with the engine running is from the alternator which will have its own power path to the batteries.

Full.Monte · 07-22-2019, 01:29 PM

Quote:

Originally Posted by Sbrownstein

You are going to have to chase the PD lines from the converter to the batteries. On many coaches the converter feeds the DC power panel and from there goes through the disconnect switch to the batteries.

With the converter running, what is the voltage on your DC power panel?

Careful switching cables...can be costly.

Check the grounds on the converter and on the lower 6 volt battery. You can also put the meter between the chassis and the battery negative to see if you can find your missing voltage. Something is dropping it and it takes a bad connection and a little current to do that.

Thank you for the advice! The distance from the converter to the batteries is only about 2 feet. There doesn't seem to be any current limiter in the 12v + line going to the + battery terminal. But there seems to be one in the cable from the - terminal on battery 1 to the + terminal on battery 2. There is no evidence that the converter goes to a DC power panel before it goes to the house battery bank. I'm thinking that the current limiter between the batteries likely has an approx. 1 volt drop in it. I know diodes do this, but am unfamiliar with this application or what's inside the fat part of the cable.

Full.Monte · 07-22-2019, 01:32 PM

Quote:

Originally Posted by spdracr39

Has it ever worked properly ? If the cables are undersized and the converter is located a good distance from the batteries the voltage drop could be significant. As stated above a loose connection somewhere in between could be an issue. I don't see how old your rig is but corrosion inside the cables can also be an issue.

The distance from the converter to the battery bank is about 2 feet of battery cable. The rig is 2004. corrosion in the cable is possible, but not too likely from my inspection.

Full.Monte · 07-22-2019, 01:36 PM

Quote:

Originally Posted by bigchick

my thoughts are that the 12.4 volts you got at the battery was the battery voltage only without any voltage from the converter. you could confirm this by measuring voltage at the batteries without the generator and then again with the generator running.

if both readings are the same you are not getting power from the converter. first places to look would be the battery disconnect switch and the resettable 12 circuit breaker. these will be in the power path from the converter to the battery. or of course a loose connection.

if the voltage measurements at the battery change between the with generator on or off readings it is probable that you have a bad / loose / corroded cable or connection somewhere on the power path. this will take inspection and correction.

the higher reading with the engine running is from the alternator which will have its own power path to the batteries.

I think you are correct. The batteries are not being charged with the generator and converter combination. The voltage was the same 12.4 volts with and without the converter connected. Right now, I'm suspecting the auto-resetting thingy in the connecting cable between the two batteries, or a loose connection on the ground side. I've already checked the + side.

bigchick · 07-22-2019, 05:35 PM

let's take a deep breath and confirm what you have.

you say when the generator is running you have 13.7 volts on the converter output terminals. but you only have 12.4 across the battery terminals regardless of whether the generator is running or not. the 12.4 is across the positive terminal of one battery and the negative of the other (6 volt in series). what is the voltage at the converter output terminals when the generator is not running?

that current limiter in the battery cable between the two batteries makes no sense. if it was dropping the converter voltage it would also be drop the engine alternator voltage.

you say the battery cables from the converter to the batteries are only 2 feet.

the only thing i am thinking of is that there is a problem with the cables that is causing a voltage drop. but if there were i would also expect it to drop the voltage at the converter terminals with the converter off. i would expect them to have the 12.4 same as the batteries. i am discounting the generator not producing power and the converter reverse polarity fuses being blown as you say you have 13.7 at the converter terminal when the generator is running.

other than the above i am at a loss.

Sbrownstein · 07-22-2019, 05:42 PM

First, if you are measuring between the positive post and ground, it doesn't matter what the "thingy" in the cable is, you should still see 13.7 volts. If it is a diode that drops .75 to 1 volt you would still see 13.7 volts. If you take the jumper between the batteries totally out you should still see 13.7 volts.

Now, with that aside, you must be drawing current and something is dropping the 13.7 or preventing it from reaching the batteries. If you are only 2 feet away, measure the voltage drop from the positive converter terminal lug to the battery post. Then from the positive lug on the converter to the lug on the positive post. Do the same thing with the negative side. You have to be able to find the voltage drop, just look for it! Lugs can look good and be bad. 12.4 sounds strangely like an open circuit from the converter to the batteries. The alternator must be using different cables. If there is a black box BCC, look for the drop there. It has to be somewhere.

Rockwood27 · 07-22-2019, 08:09 PM

Do the battery cables go directly from the converter to the batteries? In many MH, both the engine and converter charge cables go to a set of relays and then to the batteries. One of the relays could be bad.

Full.Monte · 07-23-2019, 08:40 AM

Quote:

Originally Posted by Rockwood27

Do the battery cables go directly from the converter to the batteries? In many MH, both the engine and converter charge cables go to a set of relays and then to the batteries. One of the relays could be bad.

No, the cables go directly from the converter to the batteries.

Full.Monte · 07-23-2019, 08:48 AM

Quote:

Originally Posted by Sbrownstein

First, if you are measuring between the positive post and ground, it doesn't matter what the "thingy" in the cable is, you should still see 13.7 volts. If it is a diode that drops .75 to 1 volt you would still see 13.7 volts. If you take the jumper between the batteries totally out you should still see 13.7 volts.

Now, with that aside, you must be drawing current and something is dropping the 13.7 or preventing it from reaching the batteries. If you are only 2 feet away, measure the voltage drop from the positive converter terminal lug to the battery post. Then from the positive lug on the converter to the lug on the positive post. Do the same thing with the negative side. You have to be able to find the voltage drop, just look for it! Lugs can look good and be bad. 12.4 sounds strangely like an open circuit from the converter to the batteries. The alternator must be using different cables. If there is a black box BCC, look for the drop there. It has to be somewhere.

Thanks for your thinking on this. I will do your suggested tests. Yesterday, I took the MH to get an oil leak fixed. I'm not sure when they will be done with it. I'm a bit confused on one point. If there is supposed to be a current limiting device inline, shouldn't it be in the positive cable from the converter rather than in the line between the + of the first battery to the - of the second battery?

Sbrownstein · 07-23-2019, 08:52 AM

Quote:

Originally Posted by Full.Monte

Thanks for your thinking on this. I will do your suggested tests. Yesterday, I took the MH to get an oil leak fixed. I'm not sure when they will be done with it. I'm a bit confused on one point. If there is supposed to be a current limiting device inline, shouldn't it be in the positive cable from the converter rather than in the line between the + of the first battery to the - of the second battery?

There shouldn't be any current limiting device in the converter charge lines, the converter does that all by itself. However, with a series connection a current limiter (voltage drop) can be anywhere in the circuit and it would work. Don't know why you need one but it will work. Now, that being said, if the line goes straight to the battery, you should still see converter voltage between the positive post and ground anyway. I would start on the positive lead.

If your leads go straight from the converter to the battery, you could take a single jumper cable and parallel one lead and then the other and see when the voltage finally makes it to the battery. remember, if the drop is in a lug or the connection to the post, measuring from the lug to ground or from the post to ground may give you different results.

Full.Monte · 09-12-2019, 07:08 AM

Hi Guys,

Sorry for not getting back to you earlier on this. I feel a sense of obligation to report the resolution to problems I post on IRV2. On this one, I got side-tracked by a leak in an oil line. That's another post. Since no replacement oil lines are available, I had to fix it myself. Anyway, back to the issue with the batteries not being charged with the converter. You guys made me think and poke around more, and with more purpose than I had applied before. I thought back to when I replaced an old converter because it didn't seem to be doing its job. It was a single-stage converter anyway, so I upgraded to the multi-stage unit. So, I just put the new unit in and put the wires I had removed from the old unit to the terminals on the new unit. Simple! Simple, but dumb. When the new unit didn't seem to be doing the job either, I really started thinking about what was wrong, and you guys helped me. The batteries were charging off the engine alternator, but not off the converter. To make a long story short, the voltage I was reading off the batteries was just that...the battery voltage. The converter was not charging
the batteries. I ended up disconnecting the output cables from the converter and also the wires from the battery pack and did a continuity test from the converter cables to the disconnected wires on the + side of the battery pack.
Guess what? There was no connection at all! There is an inverter in the RV, too, so that added a little confusion to it. But I knew that I had to have a connection from the + side of the converter to the + side of the battery pack.
I connected a temporary wire to the terminals on both ends, and it WORKED! I immediately read 14.2 volts at the battery pack. So I replaced my temporary wire with a permanent one. Now all seems to be working.

Thank you all for the thinking. This will help a lot with boondocking, and my batteries will be charged from the generator. It's amazing how many issues to fix you find in an RV. Thanks again!