How much should a converter put out?

[path1]

Bought new batteries. Before I install them and I need to confirm which cable is pos and neg.


So I plugged into 110 A/C and with a volt meter probe at cable ends.
I'm getting a reading of 17.35 volt. Is that a good number of what a healthy converter should be putting out?

(Or does it depend on what make and model I have. Will provide that if needed, but have to move a bunch of stuff)

Thanks

[Sam_Spade]

path1 wrote:

OK...here's what it is. Looks good to me.

So....just to be sure we understand what you are saying here....the solution to the perceived high converter voltage was......connecting the battery(s), right ??

Some others who seem to know what they are talking about have said that it should not do that so you might want to keep a close eye on it for a while. Just because it looks good now doesn't necessarily mean that it will still look good tomorrow.

[path1]

OP here.....I have to do some more touch up of paint, to anxious I guess. (Thought paint was dry enough).

OK...here's what it is. Looks good to me.

13.45 on 120 a/c
13.76 with engine running (Alt charge line)
13.20 with generator running

Thank you everybody.

The link that Old Biscuit posted is very worth while if you have Parallax-electronic series 7300. I saved a copy on computer and printed out a copy for "my" RV's owners manual. Couple big clues to me were that several suggested in their posting, no big deal about higher voltage.

And Note 2 of the link said: "If the unit has correct DC voltage with “polarity” fuses removed, but does not when “polarity” fuses are in place the converter may be in over current mode. There may be a problem with either the battery, battery wiring, or a connected load. Remove battery (positive) connection at the “C” terminal or one DC load fuse at a time to determine where the problem is. Over current mode is the condition where there is a load(s) connected to the converter that exceeds the current rating of the converter. This can either be a “short” in the coach wiring or just too many things on. The output voltage will decrease as the current exceeds the rating of the converter."

This converter in question is in our x-rental Cruise America and pretty old (2001). We've had a ton of fun over the years with it. Good for shorter trips around the NW. Longer trips...wife has me convinced she could persuade a jury, that it was justifiable homicide when snowbirding in a 23 feet rv with no slides:). The other RV is her Arctic Fox trailer with the Power Dynamtics 9200. If I ever have to upgrade I'll probably will go with the PD. Lots of postings on here about how good of product and service they have.

Thanks again. This has been about the 3rd or 4th thing that you kind folks have helped me out on.

[Old-Biscuit]

Did you bother to open and read LINK I provided for testing of the 7300 Series?

Simple step by step testing........

[path1]

I think your right. I posted a question on here years ago about Parallax and remembered responses basically said that they "were" good. Smart charging technology left them behind what I understand. Batteries are from local re-builder in Northwest (budget Battery). Had good luck with them in past. Yes 12 volt, I think group 28. Also had really good luck with Les Schwab batteries, but they fibbed to me about an tire issue, so they have been removed from my shopping list.

[westend]

I'd suggest you do your new batteries a favor and not use the Parallax converter with them. I believe you said you have 12V batteries, correct? What brand/model are they?

[path1]

Op here…..
Thanks for all the help. So many postings go unanswered or the Op never responds back. Lots of postings I wonder what the final fix turned out to be. I still don’t have final answer but will post when I do.

Thought I would give a run down on how I messed up. And as you can tell I don’t know much about elec. (and can’t write worth a darn either.) I’ve rebuilt a couple RV’s over the years. And I can say with any hesitation the elec is my weakest point.
When leaving on snowbird trip… When we were closing down everything around the house and using our checklists… When I got to checklist on class C and “disconnect batteries”. I thought I can’t disconnect batteries yet. I have to start the class C and move it to where trailer is, as there is more protection from the weather in the trailer parking spot. So I pulled the trailer out to the street and moved class C over and “disconnected batteries”. Lifted the hood and removed battery cable and closed the hood. OK, that’s done “batteries disconnected”. (See where I messed up?) House batteries in class C never got disconnected, only the starting battery got disconnected.

Back home...7 months later…and discovered house batteries are dead. Tried to charge them back up, no luck. Pulled the batteries to replace. Batteries are in a tight place. When removing them I could see a red plastic collar and thought to myself, great cables are marked pos and neg. Went and got new batteries. Then when re-installing them I discovered that all cables have a red collar at the top of them. OK, no biggie to find pos and neg I’ll just follow the cables back to see which one is grounded (NEG) and just to confirm the pos I’ll plug into 120 and take a volt meter reading before I risk putting batteries in the wrong way. Plugged into 120 and with volt meter probes discovered 18 volts were coming from converter. Then made sure volt meters (3 of them, but all cheapies) were reading OK, I put new 9 volt batteries in volt meters. Tested again and same high reading of 18 volts coming from converter. Went over to trailer and did the same test with batteries removed and got 13.6 volts. But trailer has different brand of converter and don’t know if that makes a difference or not. Called Parallax help line, left message as directed, still NO RESPONSE. Cleaned up battery tray and painted. Then today put on second coat of paint that is drying as I type this.
Just wanted everyone to know how I ended up in this spot and will post final results when paint gets dry.

Thanks for all the responses.

[time2roll]

Could this explain why you bought batteries?

[KJINTF]

Chris is correct

The Parallax 7300 series are single voltage 13.6 Vdc SMPS
They operate just fine without any battery connected
The #1 failure mode is loss of output voltage under any load at all
Seen several with high output failure as well

[Chris_Bryant]

I'm going to say a 7345 is a single voltage switch mode converter- it should work fine with no battery per Parallax Power. 18 volts is way too high.

As to how much it should "put out"- it's not that kind of converter 🙂

[Sam_Spade]

path1 wrote:

So I "think" the question I have is...will I damage batteries charging them with 18 volt when plugged in?

And my answer is still the same:
IF you are measuring that voltage without a battery in the circuit.....STOP doing that because it is meaningless.

It is not unusual for it to be high with no battery present.

Charge the new battery externally.

Connect it.

Plug in the converter.

Test the voltage again.

[mkirsch]

On this other converter you measured, did you disconnect the battery first?

Simpler converters use the battery as the voltage regulator in the system, and when disconnected from the battery, will put out what seems to be an excessively high voltage. Connect it to the battery, and the converter will "calm down" to a more reasonable output.

[Old-Biscuit]

Your converter is in 'over current' mode.
Either due to failure or a shorted cable

Normal DC output S/B 13.2V DC to 14.2V DC

Parallax 7300 Series Troubleshooting Guide

[Joe417]

Path1,

You need to connect the battery and then measure the voltage at the terminals.

With converter output open(no battery) it is common to have a higher than normal operating voltage.

It shouldn't hurt the battery for the short length of time it takes to turn it on and measure the converter output.

[time2roll]

Maybe, maybe not. Watch the voltage does not climb above 13.8 over the next couple hours.
Put a replacement PD on your project list.

[path1]

OP here...

OK have good battery's in volt meters. Readings on volt meters with wives car (independent batttery not assoc with problem I'm working on)

12.70
12.61
12.74

Converter is:

(Reading on decal) Parallax-electronic series 7300, 45 amp model 7345
Input 105-130 vac 60 hz 775 watts
12 vdc fuseblock- max branch circuit fuse size: 20A
(average charge rate: .5 amps)

Another volt meter reading at battery cables was 18.08 (which is higher than first reading)

(Also have call into Parallax. (Not very user friendly so far). Tech help line says, "explain your question in a brief message and tech support will call you back" no more than 2 seconds later "thank you, your call is very important to us" click (phone disconnected). But we'll see if and when they call back.


OK... In the mean time I also took a reading on another RV that has a "Power Dynamtics 9200 series with charge wizard" Reading was 13.61
(Rest of info to small to make out)



So I "think" the question I have is...will I damage batteries charging them with 18 volt when plugged in?

Thank you