Community Forums

Gixxer600 · 09-22-2020, 09:54 PM

Hi guys,

I am having an issue and am not sure where to start. Hopefully you can help a poor fellow like me - haha.

I bought my 2010 Allegro Open Road a few weeks ago. Ever since then, after about 2 days of not running the engine the chassis battery dies. I have to use the emergency start to get it going (which I have to hold down for 2-3 min before it works in case that is also abnormal).

I don't even know where to start to figure out why this is happening. It is plugged into shore power so it seems that even if something is left on that shouldn't be wouldn't something keep the batteries charged? Why would the chassis batteries be used at all if plugged in?

Are there certain things that ONLY work on chassis batteries?

Feel free to point me to any reading if there is some basic understanding I can gain.

Thanks in advance!!

Craig

Driveby · 09-22-2020, 10:10 PM

Not sure if it’s relevant or not but our Ford chassis batts would die in our 2008 era Itasca. It was the dash radio being powered on. It ran off the chassis, not house. My guess is it is something similar to that.

Could also be that the chassis battery itself won’t hold a charge anymore. The original would be 10 years old.

Bobby F · 09-22-2020, 10:16 PM

You're going to need a volt meter now that you're an RV'er, so go to Home Depot and pick up a $10 cheapie.

Start by disconnecting the negative battery cable from your chassis battery. Take a voltage reading across the battery terminals with the meter set on the DC Voltage setting. Should be around 12.5 or so.

Leave the cable off for three-four days and then measure it again. If it has dropped down below 12 or so, your battery is shot.

If the reading is close to what it was on Day 1, then your battery is probably good and you can move on to tracing drains.

happy2rv · 09-22-2020, 10:33 PM

Quote:

Originally Posted by Gixxer600

Hi guys,

I am having an issue and am not sure where to start. Hopefully you can help a poor fellow like me - haha.

I bought my 2010 Allegro Open Road a few weeks ago. Ever since then, after about 2 days of not running the engine the chassis battery dies. I have to use the emergency start to get it going (which I have to hold down for 2-3 min before it works in case that is also abnormal).

This isn't necessarily abnormal. If the chassis battery is completely dead, it will drag the other batteries down when you parallel them.

Quote:

Originally Posted by Gixxer600

I don't even know where to start to figure out why this is happening. It is plugged into shore power so it seems that even if something is left on that shouldn't be wouldn't something keep the batteries charged? Why would the chassis batteries be used at all if plugged in?

In most RVs, the shore power only charges the house batteries, not the chassis battery. The engine will typically charge both sets of batteries while driving, but the power converter only charges the house.

Quote:

Originally Posted by Gixxer600

Are there certain things that ONLY work on chassis batteries?

There are many things that only work on the chassis batteries. Most of the automotive and "cockpit" stuff works from the chassis battery, including the dash radio. Sometimes there is a switch to change the radio to work from either. In the absence of a switch, it probably only works from the chassis battery.

Quote:

Originally Posted by Gixxer600

Feel free to point me to any reading if there is some basic understanding I can gain.

It sound like you have something that's not getting shut off. There are some things that will always draw a little bit of power, so its normal for the chassis battery to drain over weeks to months, but not for it to be completely dead in a matter of days. Unfortunately finding exactly what can be quite challenging. If you want to troubleshoot it yourself, I would invest in a clamp on DC amp meter, learn how to read it, and start pulling fuses one at a time until the load goes away. Once you've identified the fuse, then it might be easier to track down the specific problem.

Once you sort out what's draining it so quickly, unless you are driving it weekly, I would look into a dedicated battery maintainer like the Battery Tender brand to keep it charged while in storage.

My preference is to do the same for house batteries. I don't like to keep the RV powered up while it's in storage for a variety of reasons. So, I installed a true battery disconnect for our trailer and use a Battery Tender to keep the batteries fully charged without overcharging.

Gixxer600 · 09-22-2020, 11:06 PM

All great advice. I can try to test the chassis battery as suggested, but first I think it would be good to see if I have something on and draining it. Is there a way to find out what all is connected to the chassis batteries? I wonder if there would be a schematic or list of things? For instance, would some of the storage bin lights be connected to the chassis batteries? It's possible I left one on. If I knew what all was connected I could check each thing.

As for checking fuses, how exactly do you do that?

happy2rv · 09-22-2020, 11:19 PM

For the most part, you should expect any loads on the chassis battery to be in the cockpit and engine bay.

So, anything in the dash, backup cameras/monitors, radio, vehicle running lights, parking lights, head lights, engine computer, starter, transmission, etc...

All "RV" coach loads should be on the house batteries. This includes storage compartment lights, refrigerator, furnace, interior "house" lights, CO alarm, etc...

The only "storage" compartment lights I would expect might be on the chassis battery would be in the front radiator compartment.

Quote:

As for checking fuses, how exactly do you do that?

In this case, you would be pulling the fuse to see if the current draw is reduced. So, the clamp on amp meter, would be clamped around the battery cable and observe the current being drawn. Assuming it shows a current draw with the switch off, pull a fuse and check whether the current draw went down. If not, put it back and go to the next. Once you find a reduction, look at what that fuse is feeding, assuming it's labeled. There may be a fuse block under the dash and another one in the front radiator area. There could also be things tied directly to the battery by a previous owner.

You can google DC clamp meter to get an idea of how to use one. If you are looking for one, make sure it says DC, a lot of the clamp meters are AC only.

Gixxer600 · 09-23-2020, 12:05 AM

Something like this perhaps?

https://www.amazon.com/Multimeter-Au...840980&sr=8-10

Winemaker2 · 09-23-2020, 05:37 AM

Quote:

Originally Posted by Bobby F

You're going to need a volt meter now that you're an RV'er, so go to Home Depot and pick up a $10 cheapie.

Start by disconnecting the negative battery cable from your chassis battery. Take a voltage reading across the battery terminals with the meter set on the DC Voltage setting. Should be around 12.5 or so.

Leave the cable off for three-four days and then measure it again. If it has dropped down below 12 or so, your battery is shot.

If the reading is close to what it was on Day 1, then your battery is probably good and you can move on to tracing drains.

If any RVer is looking to add a digital Volt ohm meter to their arsenal id suggest spending a few $ more and looking for one with a clamp on DC ammeter. Make sure it does DC amps as many will only do AC Amps.
It will come in handy for troubleshooting things like this... parasitic batty drain, charger operation, etc.

happy2rv · 09-23-2020, 06:00 AM

Quote:

Originally Posted by Gixxer600

Something like this perhaps?

https://www.amazon.com/Multimeter-Au...840980&sr=8-10

yes, that looks like a good candidate.

Gixxer600 · 09-23-2020, 09:44 AM

Quote:

Originally Posted by happy2rv

yes, that looks like a good candidate.

Ordered! So when I get it, where would you begin? I need to see if I can find the fuse boxes obviously. So if I clamp this AT the battery I guess that means I have to run back and forth every time I take a fuse out to see if it made a difference, or have a helper?

AnotherMike · 09-23-2020, 10:08 AM

You may be unhappy on the DC current clamps. I've seen several that don't work well under 1 amp - they deliver unstable / varying numbers if they deliver anything at all. I've found that to get accurate readings below an amp you need to remove the battery cable and put the meter body inbetween the battery post and the battery cable. And the meters themselves have fuses in them, and even the Harbor Freight cheapie red colored meters have fuses inside. You will blow one eventually, you will want to have spares available. Note that some manufacturers like Fluke (my preferred meter for serious measurements) use uncommon fuses (and they use two, and the values are different). Fortunately the local Grainger and McMaster-Carr industrial supply stores carry them... I buy them 5 at a time and keep them in a baggie inside the meter case.

Quote:

Originally Posted by Gixxer600

Ordered! So when I get it, where would you begin? I need to see if I can find the fuse boxes obviously. So if I clamp this AT the battery I guess that means I have to run back and forth every time I take a fuse out to see if it made a difference, or have a helper?

If you want to spend some serious money Fluke has a model 233 series meter (list price about $350) that has a detachable display... I don't know if any other manufacturers have copied that detachable display feature.

With one of those you can have the measurement part connected to the house battery and the display in your hand and up to 10 meters / 33 feet (that's what the specs say). I've seen one used with the display 50 feet away... but it was a clear shot across an empty warehouse.

I don't know if the 233 series comes in a clamp-on version but there is a clamp-on accessory for it. However the Fluke DC Clamp accessory is one of those that isn't recommended below one amp.

But a helper is easier. All you want to know is if the numbers on the display change... and then when they do he/she calls off the new number.

Mike

Gixxer600 · 09-23-2020, 10:14 AM

Quote:

Originally Posted by AnotherMike

If you want to spend a bunch more money Fluke came up with a model 233 series meter that has a detachable display... don't know if it comes in a clamp-on variant, but there may be a clamp-on accessory for it. And I don't know if any other manufacturers have copied that feature.

With one of those you can have the measurement part connected to the house battery and the display in your hand and up to 50-60 feet away.

But a helper is easier. All you want to know is if the numbers change... and then when it does call off the new number.

Mike

Yea I saw the Fluke but it was mucho expensive. So I will opt for the helper! Or I will pull 5 at a time and then narrow from there if I dont have one. Or I could maybe facetime my kid's ipad and point it at the meter so I can see from my phone.

happy2rv · 09-23-2020, 05:26 PM

Quote:

Originally Posted by Gixxer600

Ordered! So when I get it, where would you begin? I need to see if I can find the fuse boxes obviously. So if I clamp this AT the battery I guess that means I have to run back and forth every time I take a fuse out to see if it made a difference, or have a helper?

Yes, probably easiest with a helper. You might be able to locate the wire feeding the fuse box inside, but its usually not in an easily accessible place. So its probably easiest just to have a helper.

Dennis123 · 10-02-2020, 03:28 PM

Check the reset button on the inverter box. My box is standing on end and reset in on the bottom. Keep looking you will find it. Good luck.

Quote:

Originally Posted by Gixxer600

Hi guys,

I am having an issue and am not sure where to start. Hopefully you can help a poor fellow like me - haha.

I bought my 2010 Allegro Open Road a few weeks ago. Ever since then, after about 2 days of not running the engine the chassis battery dies. I have to use the emergency start to get it going (which I have to hold down for 2-3 min before it works in case that is also abnormal).

I don't even know where to start to figure out why this is happening. It is plugged into shore power so it seems that even if something is left on that shouldn't be wouldn't something keep the batteries charged? Why would the chassis batteries be used at all if plugged in?

Are there certain things that ONLY work on chassis batteries?

Feel free to point me to any reading if there is some basic understanding I can gain.

Thanks in advance!!

Craig