Puzzling power Problem

xraymiller · 11-26-2018, 09:34 PM

I've had this 2016 Jayco Precept 31UL for about 3 days. Unfortunately our walk-around from LazyDays was terrible. they guy didn't seem to know much and guessed at a lot of stuff.

So over the weekend we've been moving all of our stuff in. Just running off the house batteries. I even ran the generator when the batteries showed 2/3 and topped them off. I went out to take a measurement this evening and none of the lights would come on. I opened the control panel to see what voltage the inverter was and it was off. I checked the breakers by the foot of the bed and they were fine. I even tried to start the generator from the drivers seat and nothing happened.

The main battery switch appeared to be on because the red indicator light was on. I flipped the main toggle switch a few times, nothing. I have no idea what is happening at this point. So I decided to start the vehicle. Still, none of the light switches worked and the inverter was still blacked out. The panel for checking battery/fresh/gray/black worked the whole time. I went back and tried the generator again and this time it started. A few seconds later the lights came on and the inverter came on.

Just to try and understand things I toggled the main power switch by the door again and the lights went out including the red indicator light for the main power switch. So I really don't understand what happened. I imagined that the RV is in a boondocking state. The batteries are charged but something wasn't working as expected.

Hopefully this is enough information for someone to point me to an answer.

hawkster · 11-27-2018, 07:16 AM

Since I'm not a boodocking expert I'll just guess some. When not plugged to power the red switch by the door should generally be off when you're not using the rig. This will shut off draw on house batteries. You also had the inverter on which draws off 12volts. Maybe when you picked it up the batteries were low from sitting. And also when you ran the generator maybe the panel just shows full on battery but it's reading the charging from generator the batteries really aren't charged yet.

I do know when plugged in and no usage the converter goes into a maintenance mode charging at 13.2 volts. There's a button on it that you can press going to two more higher charging rates, on shore power.

Hope I didn't confuse the issue. Good luck.

xraymiller · 11-27-2018, 09:33 AM

As far as I can tell, the batteries ran down too much. Even though I left the master power switch on, I didn't leave any lights on or any thing else that I can think of. I wouldn't think the batteries would run down so quickly with practically nothing on.

Vicr · 11-27-2018, 11:31 AM

There are a lot of us here that are extremely knowledgeable with the RV electrical systems (I've been an electrician for 35 years) and one bit of information (the most important) is your battery voltage during the different stages of your events. The gauge in the coach is a POS. Go buy a digital true RMS multi meter and report back with your actual voltages. It nearly impossible to troubleshoot electrical issues over the internet and some people have made it a hobby to respond with all kinds of speculative answers. The previous poster Hawkster, whom I know, is not included in that group.

NickM · 11-27-2018, 12:03 PM

I agree with Hawkster and Vicr, you need an accurate method of checking voltage. Battery condition is also something that can be measured at most automotive stores.

My 2016 35S began having weird symptoms like yours back in the summer. Sometimes I would arrive at a campground and the generator would not start, batteries were dead even though they receive some charge from the engine alternator.

I finally replaced them with a pair of Energizer Group 31 AGM batteries and all the problems disappeared. My conclusion is that I let the coach set in storage through the first winter and drained the OEM house batteries completely. They stayed in this condition for several months at very low ambient temps. I'm pretty sure this damaged the batteries considerably.

Even with the master disconnect switch de-energized there is still some residual current draw from the coach. The dealer measured 2.6 amps in this condition. My solution is to install a mechanical disconnect switch for the house batteries so that the coach is completely disconnected from the batteries when in storage.

My coach has been at the dealer since October 1 and I'm afraid the batteries will be flat again.

Good luck and keep us posted.

xraymiller · 11-27-2018, 09:15 PM

I have a multimeter, but I don't think it is a TrueRMS (which I never heard of). Do you have a system or method of testing? For instance, turn master switch off check voltage (and/or amps). Turn main power on, check. Turn on inverter, check. Something like that?

NickM · 11-28-2018, 07:14 AM

xraymiller,

I would remove the batteries and take them to an automotive store that can load test your batteries first. If they test good, re-install and start testing.

Turn off shore power or disconnect your cable from the pedestal.

Turn your master switch off and measure house battery voltage. Then turn on the master to see if voltage changes. Progressively turn on devices that load your house batteries, lights, inverter, furnace and watch for voltage drop. You want to leave all the 12v devices on to create a load on the house batteries.

When done with your tests, turn off all the 12V devices, start the coach engine and insure that your alternator is charging the house batteries. You should see 13.6 or more at this point.

Turn off the coach engine. If you have shore power available connect your power cable and measure voltage again. You should see charging voltage from the converter, again 13.6 or greater. If you don't have shore power available start the generator. This will insure that your converter is providing charging voltage to the batteries.

If your house battery voltage starts falling off as you increase the load on the system it gives you a rough idea of battery capacity. Stout batteries with a good charge should not have excessive voltage drop. My el cheapo OEM batteries dropped under 11V pretty quick.

xraymiller · 12-02-2018, 08:40 AM

I think what I am going to do is replace these with the maintenance free type. The RV has to go back to LazyDays for some repairs anyway, and I’d rather have peace of mind with new batteries.

But I do have a new question relating to the inverter. The RV manual has 3 paragraphs on it. I’m a little confused on when to actually turn it on. I assume if I’m hooked up to shore power or on the generator that it doesn’t need to be on. But then if it’s only used when boondocking, it will run the batteries down quickly (because of the fridge).

NickM · 12-02-2018, 12:32 PM

You need the inverter when boondocking. Never on shore power or when the generator is running. Sometimes I turn mine on when I need 120V in the coach while we are driving but that's not often.

Yes, it is hard on the batteries when boon docking, that's why many RV'ers will add solar charging.

When we spent the night in Atlanta at Safety Systems awaiting installation of a steering stabilizer I shut the generator off at 10PM. Turned the inverter on and went to bed, fridge was on LP so the only things consuming power were my cpap and CO, LP monitors. 1 AM the batteries died, they were about 8 months old.

I'm now running Energizer Group 31 AGM batteries but I feel sure that I would not get more than 6 hours under the same conditions. I'm not equipped for boon docking and don't expect to spend many nights without reliable power.

Vicr · 12-02-2018, 12:43 PM

Your refer isn't connected to your inverter, just the TV's and the outlet in the electronic drawer in front of the passenger seat.
You don't want "maintenance free" batteries you want Deep Cycle batteries.

SloPoke · 12-02-2018, 01:07 PM

One of the most effective tools you will have in your motorhome will be a good quality Multitester and a Battery Load Tester.

I have this model, use it every time I have a electrical related symptom. It will draw 130A for 10 Seconds with an analog volt reading across the load test. It is the easiest way to isolate a bad (or dying) battery in our bank of batteries on the Seneca.
https://www.amazon.com/OTC-3181-Heav.../dp/B000O3U2UQ

I've owned this for over 30 years, it has saved us from replacing good batteries before - and helped troubleshoot charging issues too.

xraymiller · 12-02-2018, 01:30 PM

Quote:

Originally Posted by Vicr

Your refer isn't connected to your inverter, just the TV's and the outlet in the electronic drawer in front of the passenger seat.
You don't want "maintenance free" batteries you want Deep Cycle batteries.

I thought there was a deep cycle maintenance free battery?

xraymiller · 12-02-2018, 01:33 PM

I wonder if the inverter being on was the cause of this problem....

I bought a 20amp to 30amp adapter to connect into my 30amp to 50 amp adapter, just to power the lights in the RV while sitting at the house, but my GFI outlet on the side of the house tripped every time.

I intend on getting an electrician to install a 50amp hook up on the house. This was just for the time being.

Vicr · 12-02-2018, 02:15 PM

"Maintenance Free" batteries aren't really maintenance free if they are lead-acid batteries as you have to periodically add distilled water. AGM's on the other hand are maintenance free but require a more advanced charger than what the converter can deliver. I have both on my Precept and charge them with different chargers.

The inverter does draw current when on as well as other "parasitic loads"

when the coach power switch has been turned to off. I have installed a battery disconnect switch which completely disconnects my batteries.

xraymiller · 12-02-2018, 02:48 PM

Quote:

Originally Posted by Vicr

"Maintenance Free" batteries aren't really maintenance free if they are lead-acid batteries as you have to periodically add distilled water. AGM's on the other hand are maintenance free but require a more advanced charger than what the converter can deliver. I have both on my Precept and charge them with different chargers.

The inverter does draw current when on as well as other "parasitic loads"when the coach power switch has been turned to off. I have installed a battery disconnect switch which completely disconnects my batteries.

Yikes, right next to the propane!!

I've been scouring internet and everyone seems to be going to either the AGM or gel. I have not seen the argument raised about converters not working to their full potential with those batteries. You've given me more stuff to research.

SloPoke · 12-02-2018, 08:01 PM

Quote:

Originally Posted by xraymiller

Yikes, right next to the propane!!

I've been scouring internet and everyone seems to be going to either the AGM or gel. I have not seen the argument raised about converters not working to their full potential with those batteries. You've given me more stuff to research.

Agree - Go get the knowledge...

We budget over 1M in batteries a year where I work - Crown is one of the most respected in that industry - here is one article about Wet vs AGM.
AGM vs Flooded Batteries - What You Need to Know

Vicr · 12-03-2018, 02:00 PM

[QUOTE=xraymiller;709940]Yikes, right next to the propane!!

What are you Yikes-ing about? The propane is a closed system and the switch causes no flames or arcing.

xraymiller · 12-03-2018, 02:18 PM

[QUOTE=Vicr;710150]

Quote:

Originally Posted by xraymiller

Yikes, right next to the propane!!

What are you Yikes-ing about? The propane is a closed system and the switch causes no flames or arcing.

I will defer to your expertise. The way my brain sees that, you have to fill the propane right there so leakage can occur. And a switch connects and disconnects electricity so an arc is always possible. However unlikely, the key elements are there.

Vicr · 12-04-2018, 02:32 PM

Quote:

Originally Posted by xraymiller

I will defer to your expertise. The way my brain sees that, you have to fill the propane right there so leakage can occur. And a switch connects and disconnects electricity so an arc is always possible. However unlikely, the key elements are there.

Xray, maybe you are not familiar with the Precept utility bay. In it is the propane tank, batteries and relays with exposed electrical connections. I have not heard of any Precepts exploding as a resulting from a relay switching at the time of a a propane tank fill. I also don't plan on operating my battery disconnect switch, which is mounted in a sealed metal junction box, under full load (which may or may not cause a tiny arc at the contact points) at the same time an errant propane dispenser tech fills my tank with out the filler properly screwed into the inlet valve on my tank.
Also, as a commercial and industrial electrician for the last 35 years and my extensive knowledge of electrical systems as well as a working knowledge of closed gas, vapor and fluid systems the location of my battery disconnect switch is completely safe.

xraymiller · 12-05-2018, 01:41 PM

Quote:

Originally Posted by Vicr

Xray, maybe you are not familiar with the Precept utility bay. In it is the propane tank, batteries and relays with exposed electrical connections. I have not heard of any Precepts exploding as a resulting from a relay switching at the time of a a propane tank fill. I also don't plan on operating my battery disconnect switch, which is mounted in a sealed metal junction box, under full load (which may or may not cause a tiny arc at the contact points) at the same time an errant propane dispenser tech fills my tank with out the filler properly screwed into the inlet valve on my tank.
Also, as a commercial and industrial electrician for the last 35 years and my extensive knowledge of electrical systems as well as a working knowledge of closed gas, vapor and fluid systems the location of my battery disconnect switch is completely safe.

Thank goodness we have experts like you here to set all of us newbies straight.

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