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Thermoguy

Graham, WA

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Posted: 05/15/22 11:10am Link  |  Quote  |  Print  |  Notify Moderator

I'm trying to determine if I have 2 different problems - so thank you for all the input.

First, when out of the trailer for the winter, I had them on a trickle charger - not all the time, but would put them on for a week or 2, then let them rest, then back on, etc. They were fully charged when I put them back in the trailer.

Yesterday at 4PM I measured the voltage at the batteries, 12.64 across both - 12.67 at the trailer leads to the batteries - measuring the red lead where it comes from the converter and measuring the white ground in the battery compartment. Also measured both batteries - L 6.29 R 6.27.

At 10AM measured again, trailer unplugged from shore power since 4PM last night, everything off that can be turned off. 12.29V DC, L 6.17 R 6.13. From what I can determine, I am at 60% charge after 1 night with no load.

I guess I need to take the batteries to have them tested at, they are not even 2 years old.

I am confused by the comments, converter is OK, need new converter...

I guess a question, what should the fully charged voltage across the batteries be? I think it is 12.8 - 12.7 considered full. But on the comments above, should I see 13.2? I'm leaning towards a new converter but need to know if the problem is the batteries before I buy a converter. Need to act soon as only a couple weeks before our next trip with no power...

BFL13

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Posted: 05/15/22 12:02pm Link  |  Quote  |  Print  |  Notify Moderator

First thing is the batteries while being charged get up to a higher voltage than what they rest at when fully charged and not being charged.

So 14.6 if that is what the charger gets them to and then after they stay at that until fully charged (amps have tapered right down, and hydrometer says SG is up to where it belongs when fully charged--say 1.285 or whatever then they sit at 12.75 or whatever. Takes time for that voltage to fall and until it gets down to 12.75 say they are passing through 13 on the way down, that is called a "surface charge" the amount it is over "resting" voltage.

Second thing is the battery can look good from its voltage before any load is on it, then once loaded, the voltage will drop somewhat depending on the amps being drawn by the load. eg if batts are at 12.6 and the furnace comes on, it might be showing 12.4 or whatever.

BUT if the furnace comes on and voltage drops to 12.0, then you know the batts are "collapsing under load" so out comes the Visa card. [emoticon]

Meanwhile, the converter (with 120v input) with no battery in the RV is supposed to show 13.6ish and run the 12v things. It too might collapse under load or have a weird voltage that is too high like 18v or whatever.

With the WFCO if the battery is connected and the battery is low enough so the battery voltage stays under 13.2v (the trigger amount) for its initial spike, then the WFCO should kick into 14.4v. Many don't for various reasons ever see that low of an initial spike so they stay at 13.6 and only do a slow charge on the battery.

So yes, two separate things to look at before connecting the battery, then see what happens.

Your overnight drop in battery voltage could still be from an unknown mystery draw. If you have an ammeter or battery monitor that shows amps, you can see if there is an amps draw right away where it might not show as a voltage sag until some time has passed.

Some mystery draws that have been found include 12v tank heaters, somebody pulled the emergency brake switch on a trailer, TV antenna booster, 12v lights in underside compartments left on with doors closed so you can't see the light is on, 7-pin connected and the tow vehicle is drawing from the RV battery (happens with Chevs--no isolator like a Ford has)

If going to get batteries load tested they are supposed to be full when the test is done.


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Thermoguy

Graham, WA

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Posted: 05/15/22 01:14pm Link  |  Quote  |  Print  |  Notify Moderator

BFL13 wrote:

First thing is the batteries while being charged get up to a higher voltage than what they rest at when fully charged and not being charged.

So 14.6 if that is what the charger gets them to and then after they stay at that until fully charged (amps have tapered right down, and hydrometer says SG is up to where it belongs when fully charged--say 1.285 or whatever then they sit at 12.75 or whatever. Takes time for that voltage to fall and until it gets down to 12.75 say they are passing through 13 on the way down, that is called a "surface charge" the amount it is over "resting" voltage.

Second thing is the battery can look good from its voltage before any load is on it, then once loaded, the voltage will drop somewhat depending on the amps being drawn by the load. eg if batts are at 12.6 and the furnace comes on, it might be showing 12.4 or whatever.

BUT if the furnace comes on and voltage drops to 12.0, then you know the batts are "collapsing under load" so out comes the Visa card. [emoticon]

Meanwhile, the converter (with 120v input) with no battery in the RV is supposed to show 13.6ish and run the 12v things. It too might collapse under load or have a weird voltage that is too high like 18v or whatever.

With the WFCO if the battery is connected and the battery is low enough so the battery voltage stays under 13.2v (the trigger amount) for its initial spike, then the WFCO should kick into 14.4v. Many don't for various reasons ever see that low of an initial spike so they stay at 13.6 and only do a slow charge on the battery.

So yes, two separate things to look at before connecting the battery, then see what happens.

Your overnight drop in battery voltage could still be from an unknown mystery draw. If you have an ammeter or battery monitor that shows amps, you can see if there is an amps draw right away where it might not show as a voltage sag until some time has passed.

Some mystery draws that have been found include 12v tank heaters, somebody pulled the emergency brake switch on a trailer, TV antenna booster, 12v lights in underside compartments left on with doors closed so you can't see the light is on, 7-pin connected and the tow vehicle is drawing from the RV battery (happens with Chevs--no isolator like a Ford has)

If going to get batteries load tested they are supposed to be full when the test is done.


Thank you for all the detail.

I don't have a hydrometer so won't be doing that test.. But thank you. I've thought about getting one but haven't.

It seems like the WFCO might not be working right based on your info. But it could be the battery issues. Will post more in next thread.

Question, where do you measure the amp draw? Would the positive lead to the batteries give you that measurement? I do have a clamp on amp meter.

* This post was edited 05/15/22 01:21pm by Thermoguy *

Thermoguy

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Posted: 05/15/22 01:20pm Link  |  Quote  |  Print  |  Notify Moderator

Update - thank you all for the help.

Had the batteries tested at Batteries Plus Bulbs - both showed a bad cell. Batteries less than 2 years old. But no warranty, no pro rate on golf cart batteries.

Went to Costco and bought 2 more. I was a fan of the Duracell before today. Even though they have more AH, 18 month old batteries don't get me buying new ones. Saved $60 buying at Costco.

But, I still need to figure out why this happened. Did my trickle charger fail me this winter? Although I tested with a meter and 6.3V seemed OK. Is the WFCO failing me? The batteries have only been in the trailer since the end of March, so only a few weeks this year. Could a converter kill the batteries that quickly? Can a bad cell be caused by the converter or charger? Not sure but will research this.

From what I am seeing, the upgrade to a PD4635 converter would be a worthwhile investment? It's not that bad and there is a direct replacement if I can find one.

time2roll

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Posted: 05/15/22 01:56pm Link  |  Quote  |  Print  |  Notify Moderator

The WFCO very likely is chronically undercharging the batteries from not shifting to boost mode.
The PD4635 and PowerMax PM3 MBA series will both work far better. Both excellent for winter storage.
Both compatible with a lithium battery if that is a possibility next time battery is needed.

Winter trickle charger starting with a large partially discharged battery will never catch up.


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BFL13

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Posted: 05/15/22 02:28pm Link  |  Quote  |  Print  |  Notify Moderator

The bad cells could have been damaged if the batteries were dropped maybe before you bought them), who knows. Doubt had anything to do with the trickle charger, but you can check its voltage too, same way--use your voltmeter on its clamps

You plug in the RV and that should power up the WFCO, but it needs 120v not lower than 105v so if on a long cord from the house check the 120v value in the RV when the WFCO is running.

You measure the converter's voltage with your voltmeter- best place is at the converter's terminals, but when installed you can use the "battery wire lugs" on the DC fuse panel- easier to get at. You can use the wire ends that go on the battery too. Should be 13.6ish. You said it was 14.65? What is it now? Guys here can say what's what depending on the answer.

You want a 35a converter to go in there although a higher amp would charge those 6s faster and not mean so long of a gen run time. BUT the RV wiring and fuses are for 35 amps so stick with that. BUT if you do want faster charging and less gen time to get those 6s recharged off grid you can do that with a different battery charger that has higher amps that you can take along. You don't have to recharge with just the WFCO.

PowerMax and PD make replacement lower portion "MBAs" for the WFCO if it turns out you need a new converter. If you can't get one in time for the upcoming trip, you don't need to use the WFCO at all so no panic.

You can operate on battery and use a portable charger with the gen to recharge the batts as needed. BTW the pair of 6s will easily take 60 amps charging but it is hard to find a typical charger with that many amps. So you could buy a 60 amp deck mount converter and use that as your portable charger--but the generator has to be able to run that. Needs a 2000 not a 1000.

So you are all set whatever shape the WFCO is in.

To look for a mystery draw, turn off the charger. See what amps are being pulled. Then take out each fuse in the DC panel one at a time and note the amps draw each time. Note some draws are not fused at the panel. Slides and jacks and radio and LP alarm normally from the battery directly so to capture all the amps use the neg battery to frame "ground" wire. Unless there are other load neg wires to check on the neg battery post Or use each individual pos wire to the battery.

Thermoguy

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Posted: 05/15/22 03:20pm Link  |  Quote  |  Print  |  Notify Moderator

Thank you time2roll and BFL13.

I was leaning towards the PD as on this site some have posted the PowerMax doesn't go in to boost mode. Which seems like the problem I might be having. I have the trailer plugged in to shore power and it measures 13.65V DC. measured at the box as well as at the battery terminal - but no batteries connected. It seems like it should be in boost mode right now, trying to boost charge. Reading the WFCO manual it should be at 14.4 boost mode with 13.6 as absorption and 13.2 at float mode. Not sure I am getting those numbers correctly. Reading on the PD, it looks like similar stages. I also checked the AC side and it is at 118V AC.

Thank you for the info on the charging, I will bring a charger with me and just use that if I need to charge the batteries, bypassing the WFCO. Although, we usually run AC power when we run the gen just to have power. I'm not a fan of running the gen, but the wife usually wants to run a hair dryer, coffee maker or Micro when we use it. We won't be needing A/C this time of year...

I think my next test will be to plug in the new batteries, run some lights, etc, let the batteries run down to 80% or so, then use the WFCO to recharge and see if it charges, if it does, then I don't need a new converter, if it doesn't then I do. I think a lot of what I was seeing was the bad batteries. I know from past experience when the batteries start not charging correctly, everything else goes haywire. I can also check my amp draw when doing this to see if I am getting a draw when I think everything is off.

Again, thanks for the help. I read this site a lot and get lots of ideas. Some day we will upgrade and probably need even more help.

Thermoguy

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Posted: 05/15/22 03:31pm Link  |  Quote  |  Print  |  Notify Moderator

Measured the AMP's with no load - measured at .2AMP's. Not sure if that is good or bad or indifferent. Thanks

BFL13

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Posted: 05/15/22 05:17pm Link  |  Quote  |  Print  |  Notify Moderator

With the WFCO it should be at 13.6ish now and it is. Good to go! [emoticon]

You will only see the WFCO go into boost if it sees that 13.2v trigger, which it might if your batts are really low when you start the recharge. Many people never see theirs do 14.4 the way their RVs are set up.

The PowerMax goes into boost at first every time it starts (I have those) and then drops to 13.6 after a set time. Depends on the model how long a time it stays at 14.x. Some were only for 15 minutes same as Iota's 15 minutes. The newer LK models do 30 minutes. That is too short in many cases.

However, you can choose to use the LK model in its adjustable voltage mode, where you dial in say 14.7v and it stays there till you dial in some other voltage. That is perfect! You leave it at 14.7 until the batts are truly full (near zero amps and SG right up) and then you dial in 13.6 and it stays there till you change it.

I am not sure you can get at the adjustment dials with the MBA LK lower portion installed like in their picture. Seems to me it has to go in facing the other way to put the adjustment dials up front where you can get at them. No trouble with the deck mount LK of course--set it down how you like.

The PD might do 14.4 at first depending on what it "sees" but you can use the Charge Wizard to make it kick up to the 14.4 and it stays there for four hours. That works too but you can't pick other voltages.

Since off grid you only do 50-90s at most or 50-80s on gen time you just leave the LK at 14.7 and shut off the gen when you like. The batts will not be full but be as high as you have time for. Then at home, you plug in and at 14.7 get them full and now dial in 13.6 until next time. Gottaluvit

Your no- load amps look very good. There are always some tiny loads like the LP alarm or radio memory.

Good idea to have a spare charger along anyway even if you are on shore power in case the converter dies. You can carry on getting 12v from battery and recharge as required with your portable charger plugged into shore power. It is not a converter so you can't just leave it on. So you don't have to go home. "Be Prepared"

Ok so IMO your best bet is leave the WFCO as is, and get one of these as your portable charger (assuming you have a 2000w gen, not a 1000)

https://www.boatandrvaccessories.com/pro........-w-led-light?_pos=4&_sid=31694406c&_ss=r

LittleBill

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Posted: 05/15/22 06:55pm Link  |  Quote  |  Print  |  Notify Moderator

"The PD might do 14.4 at first depending on what it "sees" but you can use the Charge Wizard to make it kick up to the 14.4 and it stays there for four hours. That works too but you can't pick other voltages."

You absolutely can change to whatever stage you want on the PD with a wizard.





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