What’s Killing My Battery?

[Olroache]

On a trip last July departure day I went to startup, nothing, dead battery. September leaving storage for the dealer, nothing, dead battery. Had 4 year old batteries replaced. Last weekend leaving a park, same thing, nothing, had to boost it. Now I’m wondering what the hell is draining my battery when I’m parked in even though I’m plugged in to shore power???? It was only 2.5 days she sat parked.

[Olroache]

I forgot to add it’s a 2009 DutchAire DP Spartan Chassis

[emiddleb]

Do you know if your RV is supposed to charge the engine batteries when plugged into shore power? Most of my brand's models are set so that shore power only charges the house batteries. An easy fix is to add a product like the Amp-L-Starts which steals a bit of power from the house batteries (being charged by shore power or gen) to keep the start batteries topped off. Do you know if your charger does both banks or just the shore power?

As far as why the start batteries are draining, there are a lot of parasitic loads that are in play even when the coach is turned off. All of the engine and transmission ECMs draw a trickle of power. Usually the dash radio (to keep the settings/stations.) I have even heard of things like power steps and 12v smoke/propane/CO detectors sometimes being wired into the start batteries so that if you flip the "salesman switch" to turn off the coach the detectors still operate.

Just some thoughts. Others who have your model coach might know more.

[nvs4602]

Get a clip on dc amp meter to see how much draw is on the battery. Then start pulling fuses one at a time until you find out which circuit is drawing the power.
https://www.ebay.com/itm/254222827059

[dusty56]

I had the same problem. Silverleaf (not sure if you have it) indicated batteries were being charged but actually they were not being charged. Turned out to be the inverter on the coach not charging the batteries. Inverter replaced, batteries working fine.

Remember your chassis batteries operate the slides so they need to be constantly charged.

[Dutch Star Don]

"Olroache"....Modern coaches have what is called a B.I.R.D. Here is the basic definition....

Intellitec’s Bi-Directional Isolator Relay Dealy – offers a new approach to charging batteries in an RV which uses an alternator. Adding a small dash-mounted switch will allow emergency starts of diesel engines, requiring up to 800 amps of starter current. Unlike proper systems that only allowed charging the RV battery from the engine’s alternator, the Bi-Directional Isolator Relay Delay – Diesel™ chargers both batteries when either one is being charged. When the coach is being driven, both batteries will be charged from the engine’s alternator. When the coach is plugged into shore power, both batteries will be charged from the converter. If neither battery is being charged, the batteries are fully isolated. The controller also senses heavy loads on either battery to prevent the wrong battery from being inadvertently discharged.

The device makes sure that your chassis batteries are being charged by your coach charger when the coach is plugged into shore power. These have not been around forever, but became standard equipment sometime around the time your coach was built. My 2005 Diplomat did not have it, even though I had a merge button for jump starting. Your coach may or may not have come with one.

You need to determine if your coach came with this system. Sometimes, in your exterior fuse panel, you may find a fuse labeled as BIRD or by directional relay. I'm not familiar with your coach so I can't tell you where the BIRD might be located, if you have one.

If your coach has worked, charged the chassis batteries in the past, you need to find the BIRD/fuses. If it didn't, you can add one.

Adding a charger is very simple. There are a few products out there. One is called AmpLStart, another called TrikLStart and lastly there is one made by Magnum Inverters, which is what I used on my Diplomat. I linked two below.

https://www.rvupgradestore.com/15-Am...mp-l-start.htm

https://www.anchorexpress.com/Magnum...l%20-%20Airmar

Lastly, your chassis batteries are running down pretty quick. Typically, I found they would last about 5-7 days before there is an issue, on coaches without a BIRD. You may have something that is causing some excessive draw. Do you by chance listen to the dash radio a lot while parked.

[Olroache]

Originally Posted by emiddleb

Do you know if your RV is supposed to charge the engine batteries when plugged into shore power? Most of my brand's models are set so that shore power only charges the house batteries. An easy fix is to add a product like the Amp-L-Starts which steals a bit of power from the house batteries (being charged by shore power or gen) to keep the start batteries topped off. Do you know if your charger does both banks or just the shore power?

As far as why the start batteries are draining, there are a lot of parasitic loads that are in play even when the coach is turned off. All of the engine and transmission ECMs draw a trickle of power. Usually the dash radio (to keep the settings/stations.) I have even heard of things like power steps and 12v smoke/propane/CO detectors sometimes being wired into the start batteries so that if you flip the "salesman switch" to turn off the coach the detectors still operate.

Just some thoughts. Others who have your model coach might know more.

Those are great questions which I’ll have to look into the answers. This just started last summer. Had no issues prior to that. Thanks for the recommendation!

[Olroache]

Originally Posted by nvs4602

Get a clip on dc amp meter to see how much draw is on the battery. Then start pulling fuses one at a time until you find out which circuit is drawing the power.
https://www.ebay.com/itm/254222827059

Thanks I’ll look into that.

[Olroache]

Originally Posted by dusty56

I had the same problem. Silverleaf (not sure if you have it) indicated batteries were being charged but actually they were not being charged. Turned out to be the inverter on the coach not charging the batteries. Inverter replaced, batteries working fine.

Remember your chassis batteries operate the slides so they need to be constantly charged.

That’s interesting. I had no problem pulling in my VERY sensitive FWS while I was charging the battery. I was still connected to shore power

[Olroache]

Originally Posted by Dutch Star Don

"Olroache"....Modern coaches have what is called a B.I.R.D. Here is the basic definition....



Intellitec’s Bi-Directional Isolator Relay Dealy – offers a new approach to charging batteries in an RV which uses an alternator. Adding a small dash-mounted switch will allow emergency starts of diesel engines, requiring up to 800 amps of starter current. Unlike proper systems that only allowed charging the RV battery from the engine’s alternator, the Bi-Directional Isolator Relay Delay – Diesel™ chargers both batteries when either one is being charged. When the coach is being driven, both batteries will be charged from the engine’s alternator. When the coach is plugged into shore power, both batteries will be charged from the converter. If neither battery is being charged, the batteries are fully isolated. The controller also senses heavy loads on either battery to prevent the wrong battery from being inadvertently discharged.



The device makes sure that your chassis batteries are being charged by your coach charger when the coach is plugged into shore power. These have not been around forever, but became standard equipment sometime around the time your coach was built. My 2005 Diplomat did not have it, even though I had a merge button for jump starting. Your coach may or may not have come with one.



You need to determine if your coach came with this system. Sometimes, in your exterior fuse panel, you may find a fuse labeled as BIRD or by directional relay. I'm not familiar with your coach so I can't tell you where the BIRD might be located, if you have one.



If your coach has worked, charged the chassis batteries in the past, you need to find the BIRD/fuses. If it didn't, you can add one.



Adding a charger is very simple. There are a few products out there. One is called AmpLStart, another called TrikLStart and lastly there is one made by Magnum Inverters, which is what I used on my Diplomat. I linked two below.



https://www.rvupgradestore.com/15-Am...mp-l-start.htm



https://www.anchorexpress.com/Magnum...l%20-%20Airmar



Lastly, your chassis batteries are running down pretty quick. Typically, I found they would last about 5-7 days before there is an issue, on coaches without a BIRD. You may have something that is causing some excessive draw. Do you by chance listen to the dash radio a lot while parked.

Great information. I will check my fuse boxes. Regarding the radio, I left my key in the acc position, the radio was powered on in aux mode the entire 3 days I was parked.

[SteveUpp]

Originally Posted by Olroache

Regarding the radio, I left my key in the acc position, the radio was powered on in aux mode the entire 3 days I was parked.

The ACC position powers up a lot of circuits besides just the radio. I wonder if the BIRD if you have one will behave differently if the key is in the ACC position. I suggest getting a DC clip on amp meter and look at the difference between OFF and ACC.

[gpounder]

Leaving the key on certainly will cause a draw but at the same time there should have been a charge coming from the house side and I think that part is not working.

Here is a easy test, you need a volt meter. With every thing off and not plugged into shore power (let it sit for at least 4 hours) measure both chassis and house batteries and write the number down.

Now plug into shore power and wait 5-10 minutes. Your charger should have kicked in and the house batteries should have risen well into the 13 and maybe 14 volt range. At these voltages now some of the power is pushed to the chassis battery and it will show a rise. It may not be very much as this is just a trickle charge. If this does not happen then the BIRD charger or similar is bad.

If you really want to fully understand the electrical system this is worth a read.
http://www.irv2.com/forums/f54/elect...me-464251.html

[twinboat]

Are your house batteries charging at 13.4 volts or more ?

If not, the BIRD will not connect the chassis battery to the house batteries and you not get any charging.

See what your house battery voltage is.

[MD-Keith]

There is also a charge bridge solenoid that can go bad and prevent the chassis batteries from charging.

https://www.irv2.com/forums/f103/cha...le-471304.html