Battery drain

Split from General / Technical for discussion of anything electrical, electronic... 12v, Inverter, Satellite, Headlights, flashlights etc.
Baja Bilo
Posts: 48
Joined: July 29th, 2020, 8:49 pm

Re: Battery drain

Post by Baja Bilo »

Blue~Go wrote: March 27th, 2021, 1:56 pm
Baja Bilo wrote: March 27th, 2021, 1:32 pm It has had this problem since I purchased it. It's not a problem if I start it everyday or
have it plugged into shore power. I think the previous owner may have dealt with the
problem and never got it solved. When I was driving it home the coach low battery
alarm went off. It has 2 new coach batteries in it.
Okay so it is draining your house batteries not the start battery? That's a different scenario than I was envisioning at first (good sleuthing, BobW!).
Baja Bilo wrote: March 27th, 2021, 1:32 pm Not knowing much about RV's I started poking around in the engine bay and found that the cable from the coach
batteries wasn't hooked up to the vehicle battery which meant the coach batteries weren't getting charged from the alternator. I'm wondering if the reason the cable wasn't hooked up was because the coach was draining the vehicle batteries.
This is one of the main functions of a "separator" (aka combiner aka isolator). When either bank drops below a set voltage (for Blue Sea, 12.76), the connection opens so current can't flow between them. Some combiners are bi-directional, so charge power could go either way (1315 for example), while others are uni-directional so power can only go one way, which is typically from start bank to house bank (to charge while driving).
Baja Bilo wrote: March 27th, 2021, 1:32 pm I don't want to tell the mechanic how to do his job but I hope he checked to see if the drain
was still there after disconnecting the coach batteries from the vehicle battery.
Your mechanic may be a crack diagnostician, and totally on top of it. He'd be the exception in my experience. many "regular" mechanics would probably have no idea how an RV is wired (a boat electrician would have a better chance). So while he may be fantastic, if it were me I'd not assume that.
Baja Bilo wrote: March 27th, 2021, 1:32 pmI think that would have been the first thing to check to find out if the drain is from the vehicle or the coach. I think I'll go there Monday and disconnect the coach stereo and see if that stops the drain on the vehicle battery. Thanks for the input.
Can you just clarify one more time what the symptom(s) are?

1) Which battery is running down, start or house? Or both?

2) Are you saying this was happening even when the cable connecting start and house banks was not connected at all? If yes, then which bank was running down, start or house?

3) When does this happen? While driving only? While parked only? Both?

There is one other little "gotcha" on the Surepower, which is that many of them have "start helper." What this does is (sneakily, without telling you) if your start battery is too weak to start the vehicle, it combines your house bank with your start bank to help start the vehicle BUT NEVER TELLS YOU. So you could have a dead or weak start battery for eons and never know it. Since a diesel takes a lot of oomph to start, if this had happened and then you drove away, maybe a cascade starts and then your house bank trips the low voltage warning?

The above scenario may not apply, but if you want to explore this further it would be great if you could elaborate on the answers to the questions above.

BG
I hear what you are saying about the "help" part of the Surepower. Here are all the symptoms. If the rig sits for let's say
2 days between starting. The vehicle batteries don't have enough juice to crank the engine enough to start it. When I turn
on the key to cycle the glow plugs the vehicle volt meter will show maybe 11 volts, then there is a click and the voltage
meter jumps up and there is enough juice to start the vehicle. That indicates the start helper you mentioned. Other times
if it won't start I'll push the boost button and it will start. So my highly uneducated opinion is telling my that the vehicle
batteries are draining first and if the rig sits long enough the house batteries follow. If it sits for over 3 days there isn't
enough juice to start the rig. The house batteries were replaced last July, the vehicle battery on the frame rail was replaced
last June, and they installed a new battery in the engine compartment this week. All batteries have been charged to full and load
tested then left over night and by the next day the vehicle batteries have drained about 30%. This shop specializes in automotive
electrics but I hear your thoughts on the difference between automotive and RV electrics. The weather is getting nice here in Idaho
and I want to use the rig but don't want to get stuck somewhere. If I go to a camp spot with shore power I'll be fine, but I'd like to
go to some out of the way spots also. How about the generator, does the starter on it get power from the house or the vehicle
batteries? I don't claim to be an ace mechanic but I kind of know some of the basics. I was a floor covering installer for 30 years
then switched trades when I was almost 50 and worked as an electrician for 10 years. I would never claim to know everything about
electrical issues home or vehicle. They are both a never ending learning process. Thanks for your input, Steve.
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Blue~Go
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Joined: July 31st, 2014, 1:01 am
Location: 1999 Concourse

Re: Battery drain

Post by Blue~Go »

Baja Bilo wrote: March 27th, 2021, 4:54 pm How about the generator, does the starter on it get power from the house or the vehicle
batteries?
I'm going to cherry pick this to answer first, just because it's quick and easy. Your generator start should come from the house batteries. (Prior to around 2000 it was wired to the start battery, but after that they moved it to the house.)

The other I need to look at a bit more because it's not as quick.

PS: A note. If you don't have the owner's manual for your 2003, have a look in the Reference section here. There is a 2004 manual which should be fairly close. But, you may also want to download the 2000 manual because I see that in 2004 they don't show as much about the DC system as they did in the older manuals. Even if one or two things have changed by 2003, it might still be handy to have.
1999 Concourse
cidevco
Posts: 27
Joined: March 14th, 2018, 7:51 pm

Re: Battery drain

Post by cidevco »

Here is my 2 cents about the house batteries losing power. During the winter I pull the 2 house batteries and the truck battery out and keep them charged on my work bench. Yesterday I opened up my rig and found a beeping sound coming from the three switches above the center mirror, the generator start switch area. HOW CAN THIS BE IF THE RIG HAS NO POWER. After digging around I found my solar panel control panel was active. I have the model that has the LED lights showing the state of charge. With a multimeter I found that this circuit was active due to the solar panel making power. By removing the fuses the chirping stops, by breaking the circuit. Where Im going with is, is that somehow the wiring from the solar panel is tied into the rigs breaker panel and suppling the 12 volt system. If the solar panel supplies power to the fuses, an easy test will be to remove the fuse on the solar control panel and see if that solves the problem. By having the solar panels energizing the fuse panel, the panel is grounded and current moves freely. remember electricity 12 volts DC or 120VAC can travel in either direction AC or DC +/- thus the drain on the batteries. Give this a try
Baja Bilo
Posts: 48
Joined: July 29th, 2020, 8:49 pm

Re: Battery drain

Post by Baja Bilo »

cidevco wrote: March 28th, 2021, 8:20 pm Here is my 2 cents about the house batteries losing power. During the winter I pull the 2 house batteries and the truck battery out and keep them charged on my work bench. Yesterday I opened up my rig and found a beeping sound coming from the three switches above the center mirror, the generator start switch area. HOW CAN THIS BE IF THE RIG HAS NO POWER. After digging around I found my solar panel control panel was active. I have the model that has the LED lights showing the state of charge. With a multimeter I found that this circuit was active due to the solar panel making power. By removing the fuses the chirping stops, by breaking the circuit. Where Im going with is, is that somehow the wiring from the solar panel is tied into the rigs breaker panel and suppling the 12 volt system. If the solar panel supplies power to the fuses, an easy test will be to remove the fuse on the solar control panel and see if that solves the problem. By having the solar panels energizing the fuse panel, the panel is grounded and current moves freely. remember electricity 12 volts DC or 120VAC can travel in either direction AC or DC +/- thus the drain on the batteries. Give this a try
Thanks for the input but my rig doesn't have solar panels
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SMan
Senior Member
Posts: 633
Joined: February 17th, 2015, 1:57 pm
Location: 7 Lakes, WA

Re: Battery drain

Post by SMan »

I am no electrical expert. That said here are my list of possible power drain items....

1) My aftermarket DVD/Radio replacing the OEM VHS player

2) The Batwing antenna power switch which is easy to leave on

3) The Co2 detector (I replaced with a battery unit)

4) The Propane Gas detector

5) Aftermarket backup camera (Even when in off my IR cameras draw voltage)

6) The LVD system itself when left on overhead.

7) Rear entry light/step/outside light switches left in on position

8) Pump switch left in on position.

9) Heat/Cooling system controls left on

10) Any other aftermarket item installed in the coach
Steve aka SMan
2004 Premier V10
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Blue~Go
Senior Member
Posts: 3716
Joined: July 31st, 2014, 1:01 am
Location: 1999 Concourse

Re: Battery drain

Post by Blue~Go »

Baja Bilo wrote: March 27th, 2021, 4:54 pm It has had this problem since I purchased it. It's not a problem if I start it everyday or
have it plugged into shore power. I think the previous owner may have dealt with the
problem and never got it solved. When I was driving it home the coach low battery
alarm went off. It has 2 new coach batteries in it.
Okay, so whether or not you have a start battery parasitic load, you have some kind of house battery drain problem (instead or also).
Baja Bilo wrote: March 27th, 2021, 1:32 pm Not knowing much about RV's I started poking around in the engine bay and found that the cable from the coach
batteries wasn't hooked up to the vehicle battery which meant the coach batteries weren't getting charged from the alternator. I'm wondering if the reason the cable wasn't hooked up was because the coach was draining the vehicle batteries.
Okay, this also means that unless you hooked that back up, your two systems are completely separate. So can you answer another question?

When this cable is NOT hooked up.
1) Do your house batteries drain? (LVD beeps)
2) Does your start battery drain? (can't start vehicle)

Once that cable is hooked up, then you have a lot more possibility of one problem bleeding over into another so there is more to think about. But if it was unhooked and you can say how it behaved, that makes it easier to diagnose.

Baja Bilo wrote: March 27th, 2021, 1:32 pm I hear what you are saying about the "help" part of the Surepower. Here are all the symptoms. If the rig sits for let's say
2 days between starting. The vehicle batteries don't have enough juice to crank the engine enough to start it. When I turn
on the key to cycle the glow plugs the vehicle volt meter will show maybe 11 volts, then there is a click and the voltage
meter jumps up and there is enough juice to start the vehicle. That indicates the start helper you mentioned.
This could only happen if you have the cable attached that runs between the start battery positive and the house battery positive (through the combiner). One simple way to help diagnose would be to detach that cable. There are lots of other possibilities, but that would make it instantly clear which "side" has the problem. Keep in mind this is a cable with two "powered" ends, so you will want to detach it on both the start battery and house battery end (otherwise the free end will be live).

I can think of a number of scenarios that we could run through about what might be happening, but now that I have thought about it, I think detached the house from the start and then seeing what you do or don't get as symptoms could be really simple and helpful (with them detached from each other, you can charge up house bank by plugging in, and charge up start bank by driving).

PS: It sounds like as you were driving home (with house/start cable DETACHED?), the LVD beeped indicating low house batteries. (If the cable was attached, then we are back to it could be many things.) If the cable was detached, and your house battery was charged (was it?), then the only load I could see drawing it down relatively quickly would be if you had the original propane refrigerator running on electrical setting (vs. propane). A propane refrigerator takes a very large number of amps to run on electricity (like ten times as much power as an actual electric refrigerator would).
1999 Concourse
Baja Bilo
Posts: 48
Joined: July 29th, 2020, 8:49 pm

Re: Battery drain

Post by Baja Bilo »

Blue~Go wrote: March 29th, 2021, 9:11 am
Baja Bilo wrote: March 27th, 2021, 4:54 pm It has had this problem since I purchased it. It's not a problem if I start it everyday or
have it plugged into shore power. I think the previous owner may have dealt with the
problem and never got it solved. When I was driving it home the coach low battery
alarm went off. It has 2 new coach batteries in it.
Okay, so whether or not you have a start battery parasitic load, you have some kind of house battery drain problem (instead or also).
Baja Bilo wrote: March 27th, 2021, 1:32 pm Not knowing much about RV's I started poking around in the engine bay and found that the cable from the coach
batteries wasn't hooked up to the vehicle battery which meant the coach batteries weren't getting charged from the alternator. I'm wondering if the reason the cable wasn't hooked up was because the coach was draining the vehicle batteries.
Okay, this also means that unless you hooked that back up, your two systems are completely separate. So can you answer another question?

When this cable is NOT hooked up.
1) Do your house batteries drain? (LVD beeps)
2) Does your start battery drain? (can't start vehicle)

Once that cable is hooked up, then you have a lot more possibility of one problem bleeding over into another so there is more to think about. But if it was unhooked and you can say how it behaved, that makes it easier to diagnose.

Baja Bilo wrote: March 27th, 2021, 1:32 pm I hear what you are saying about the "help" part of the Surepower. Here are all the symptoms. If the rig sits for let's say
2 days between starting. The vehicle batteries don't have enough juice to crank the engine enough to start it. When I turn
on the key to cycle the glow plugs the vehicle volt meter will show maybe 11 volts, then there is a click and the voltage
meter jumps up and there is enough juice to start the vehicle. That indicates the start helper you mentioned.
This could only happen if you have the cable attached that runs between the start battery positive and the house battery positive (through the combiner). One simple way to help diagnose would be to detach that cable. There are lots of other possibilities, but that would make it instantly clear which "side" has the problem. Keep in mind this is a cable with two "powered" ends, so you will want to detach it on both the start battery and house battery end (otherwise the free end will be live).

I can think of a number of scenarios that we could run through about what might be happening, but now that I have thought about it, I think detached the house from the start and then seeing what you do or don't get as symptoms could be really simple and helpful (with them detached from each other, you can charge up house bank by plugging in, and charge up start bank by driving).

PS: It sounds like as you were driving home (with house/start cable DETACHED?), the LVD beeped indicating low house batteries. (If the cable was attached, then we are back to it could be many things.) If the cable was detached, and your house battery was charged (was it?), then the only load I could see drawing it down relatively quickly would be if you had the original propane refrigerator running on electrical setting (vs. propane). A propane refrigerator takes a very large number of amps to run on electricity (like ten times as much power as an actual electric refrigerator would).
Went to the shop today. They charged everything up on Friday and it sat over the weekend.
Mechanic did a test on the vehicle battery and it was at 84%. The rig started. He told me that
the parasitic draw was .03 amps which I guess is on the high side of being within range. I think
I will do what someone else mentioned and take the lead from the vehicle battery to the house
stereo off and switch it to a lead from the coach batteries. They replaced the smart solenoid
with a different brand and replaced one of the vehicle batteries. Hopefully that lessons the draw
a little.
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Blue~Go
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Location: 1999 Concourse

Re: Battery drain

Post by Blue~Go »

Changing the radio lead to so both power leads go to the house seems like a good idea to me whether or not it is your only problem. The only negative side effect I know of is that when you turn the house batteries "off" you will lose your presets. That didn't matter to me at all whereas having a house drain on my start battery DID matter.

If you run into more "weird" problems then I think that I would start by disconnecting the cable the connects your start battery to your house battery bank. Then see where the problem goes (start or house). That would eliminate "cross contamination" problems as you diagnose.
1999 Concourse
deppstein
**Forum Contributor**
Posts: 357
Joined: July 13th, 2015, 7:07 am

Re: Battery drain

Post by deppstein »

All this talk of battery drain and parasitic load prompted me to do some poking around to see if I could get my parasitic load drain down to a bare minimum without installing a cut-off switch on the house batteries. My objective is to maximize any unnecessary drain when using the Rig (we tend to gravitate toward campsites without shore power due to fact that they tend to be more remote/pretty)....hence not wanting to bother with a cut-off switch.
Background: Our Rig is a 2004 Premier 6.8 v10 with a regular start battery, 130 amp alternator, Blue Sea 7633 separator, two 12v Group 31 105 ah house batteries wired in parallel, a PD 4645 charger/converter, and a 200 watt Zamp Solar Suitcase for use when stationary. We also carry a 1000 watt Honda Quiet generator (got rid of the on-board) for back-up charging in a pinch. Oh yea, and there is a Pure Sine 1000 watt inverter tied to house system.
Degree of Draw: When the Rig is parked in driveway (50 degree weather) with house batteries fully charged (they are in good shape), battery disconnect in off position with nothing running, the batteries generally go from 12.8-12.4 in 5 to 6 days.
What I know and have done: The inverter does not draw any power when shut off. I have pulled fuses for the coach radio, tv, and VCR (those things are long gone!). I have also verified that both detectors have no power going to them when the battery disconnect switch is turned off. And, I have verified that the electric Kwikee steps run off of the house battery (with an ignition over-ride), and they run even when the battery disconnect switch is turned off. There is a lock-out switch for the steps in the cluster of switches in rear above the closed.
It's that cluster of switches above the closet that I am currently focused on--particularly the little lights embedded in the switches themselves. One is for the ceiling light just inside the back door (for some reason this switch must be on for that light to work (I keep it off, unless using that particular light...no drain when off). Another is for the porch light outside...same thing, indicator light on only when porch light is turned on (hardly ever, and when off, no drain. And the third is for the electric step. When that electric step switch is in lock-out (i.e.; the step remains extended/no movement), the indicator light is on. When switch is off, no light and step is in regular operational mode.
And so, here are my questions at the moment:
1) Am I correct in assuming that the parasitic load to the step motor (even when not operational) will be greater than the current flowing to the indicator light in the switch when the steps are locked out?
2) Has anyone removed those indicator lights embedded in the switches? Do they draw enough to warrant doing so? (I'm focused on the step switch in particular).
3) What else, if anything, am I missing? When camping, we already do things like use nice little battery lanterns instead of coach lights, run frig on propane, turn off water pump and inverter when not using.
As always, any and all advice most welcome.
Thanks
David
brentk
Posts: 5
Joined: February 27th, 2021, 10:15 am

Re: Battery drain

Post by brentk »

david, there should not be a parasitic draw coming from the step motor with switch in the off position. all of the inductive dc motors in an RV run through a switch such as bath exhaust fan, hood exhaust for range, fantastic fan, water pump, squirrel cage fan for gas heat, air conditioner, etc. if a problematic switch lets partial dc voltage by you will know it right away as low voltage at dc motor will increase amperage, blow fuse and possibly take switch out too. normally the switch will either work or fail. so there will be more of a slow dc current draw coming from the resistive load of the indicator light. i probably would avoid that lock out switch for the power steps while boondocking. ( i have manual steps in my chinook)

also another thing that you could check is the refrigerator. mine is 120 volt a/c, propane, 12vdc. the control board is 12vdc. there is a small amperage draw on that as well. i remember boondocking with my old outback travel trailer and as soon as my batteries started to drain the very first thing that faulted and stopped working was the refrigerator while running on propane. (time to start generator and charge batteries) 12vdc is required as well as propane for frig to work.

your situation is much different than mine with your inverter setup, etc. i use my onan generator all the time mostly to run the air conditioner in the summertime. most of the places we camp have power or if not it is just for a night or so.
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