Hi everyone, I posted a week or so ago about my RV killing new batteries overnight. I took it to the shop got a brand new battery and alternator and thought everything was great. Nope! Went out a few days later to start it and of course it would not start. I jumped it with my car and it started up after about one minute. Any ideas what could be going on here?
RV Battery still draining
- Thread starter katsmith
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Are you talking about the starter battery for the RV or your house batteries that run stuff in the back. Either way it sounds like some sort of parasitic draw is taking place and the battery is not being charged. If it's the starting battery I would think a mechanic can run tests to see where the draw is taking place or if something else is going on. I'm surprised the shop you went to just threw in a new battery and alternator without testing to see what might be going on.
highdesertranger
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you have a drain on your start battery. it may or may not have to do with your aux battery system. do you know how to check for a battery drain? highdesertranger
Optimistic Paranoid
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deadwood said:
I'm not. Most shops no longer have TRUE mechanics who can test systems. They have parts changers who just change one part after another until the problem goes away.
highdesertranger
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do you know how to check for a drain? if you don't you should learn, so you don't have to deal with shops. we can help you it's not hard. highdesertranger
ArtW
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HDR is right, you have a drain, that needs to be fixeed
rvpopeye
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Just a guess but do you have a battery isolator that both batteries are connected to ?
It should be under the hood.
They are just an automatic relay and wear out with age.
I know someone ?? who had this problem and the isolator was the bad boy !!!
OH yeah and as always check all the grounds (not just looking at them , take apart and clean...)
It should be under the hood.
They are just an automatic relay and wear out with age.
I know someone ?? who had this problem and the isolator was the bad boy !!!
OH yeah and as always check all the grounds (not just looking at them , take apart and clean...)
LeeRevell
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Make sure your dome lights are going off when you close your doors. I recently had one that refused to go off. I finally had to remove the bulb. The other three have no problem.
highdesertranger said:
I honestly know nothing about fixing a vehicle and would appreciate any help you can give me to check the drains. I just spent alot of money getting the battery and alternator so Im tapped out on large amounts of cash and would really like my RV to start without being jumped. Im in AZ its getting real hot and I want to head north asap.
Trebor English
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To check for a drain:
1 Set your multimeter to measure amps. Move the red test lead to the 20 amp jack and set the knob for 20 amps DC
2 Disconnect the battery negative lead. Do this to both batteries.
3 Connect the amp meter from battery minus to the cable that used to be on the battery.
4 Watch the meter for a minute. The current used by the computer may be several amps as it starts up. In a couple of minutes it should be less than 1 amp.
5 Eventually it should go to less than .1 Amps. On my Ford that takes 30 minutes of leaving all doors alone. Each opening or closing restarts the 30 minutes.
1 Set your multimeter to measure amps. Move the red test lead to the 20 amp jack and set the knob for 20 amps DC
2 Disconnect the battery negative lead. Do this to both batteries.
3 Connect the amp meter from battery minus to the cable that used to be on the battery.
4 Watch the meter for a minute. The current used by the computer may be several amps as it starts up. In a couple of minutes it should be less than 1 amp.
5 Eventually it should go to less than .1 Amps. On my Ford that takes 30 minutes of leaving all doors alone. Each opening or closing restarts the 30 minutes.
Trebor English
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Once you know how much current is draining you need to figure out where it is going. One method is to pull fuses out one at a time to see what happens. If a fuse controls the excess drain, that should lead to the cause.
Before doing all that go around turning on and off everything to make sure it is all off. Check the ignition switch too. Just because the key comes out doesn't mean it is off.
if you have solar, disconnect the panel before disconnecting the battery.
Before doing all that go around turning on and off everything to make sure it is all off. Check the ignition switch too. Just because the key comes out doesn't mean it is off.
if you have solar, disconnect the panel before disconnecting the battery.
Trebor English
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Do you have a multimeter? If you need to get one Amazon has several under $10. Harbor Freight has one that is sometimes free with a coupon.
Particularly when measuring amps it is easy to break the meter. If you connect it across your battery it will NOT tell you how many amps are in the battery. It will blow the fuse inside the meter or just poof the meter. When you try to measure amps and it just says zero it may be poofed. Turn on the parking lights. If the drain is still zero then it likely the meter is open circuit, particularly if lights don't come on.
Particularly when measuring amps it is easy to break the meter. If you connect it across your battery it will NOT tell you how many amps are in the battery. It will blow the fuse inside the meter or just poof the meter. When you try to measure amps and it just says zero it may be poofed. Turn on the parking lights. If the drain is still zero then it likely the meter is open circuit, particularly if lights don't come on.
SternWake
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I am sad to hear that yet another repair shop threw unnecessary parts at a problem, and missed. Perhaps the battery was necessary, but the alternator replacement likely was not.
One thing to be aware of, is it takes a long time after a jumpstart for a battery to get anywhere near full.
Many people, assume a 15 minute drive after a jumpstart is all that is required and everything is just fine at that point, but the battery is NOWHERE near fully charged, and even light parasitic loads and natural self discharge can cause enough draw on the still severly depleted battery that it will require another jumpstart the next morning, and this can be confused with a parasitic draw. I am not saying this is the case, but it is a possibility.
Any battery which gets a jumpstart, really requires that it be recharged fully on a plug in charger, as even driving for 8 hours, might leave the battery only 85% charged, and when it is discharged so much that it required a jumpstart, especially a new battery, it really really wants to get a true full recharge, and that is impossible in a 15 minute drive. Recharging a battery that was dead as a doornail to full, cannot be accomplished in less than 6 hours, and this can only happen with a higher amperage source that seeks and holds a high voltage the whole time. This does not happen in 99.98% of vehicles as the voltage regulation is timid.
The parasitic draw on engine battery, if it exists, and is not just a case of overwhelming undercharging, can be negated when parked by pulling off the ground cable from the engine battery, so at least it won't get pulled to dead as doornail status every night until it is figured out.
Draining a newish starter battery to dead as a doornail time and again , will have it unable to store enough energy to do its job in a very short period, and it is not the battery's fault, nor the retailer's.
One thing to be aware of, is it takes a long time after a jumpstart for a battery to get anywhere near full.
Many people, assume a 15 minute drive after a jumpstart is all that is required and everything is just fine at that point, but the battery is NOWHERE near fully charged, and even light parasitic loads and natural self discharge can cause enough draw on the still severly depleted battery that it will require another jumpstart the next morning, and this can be confused with a parasitic draw. I am not saying this is the case, but it is a possibility.
Any battery which gets a jumpstart, really requires that it be recharged fully on a plug in charger, as even driving for 8 hours, might leave the battery only 85% charged, and when it is discharged so much that it required a jumpstart, especially a new battery, it really really wants to get a true full recharge, and that is impossible in a 15 minute drive. Recharging a battery that was dead as a doornail to full, cannot be accomplished in less than 6 hours, and this can only happen with a higher amperage source that seeks and holds a high voltage the whole time. This does not happen in 99.98% of vehicles as the voltage regulation is timid.
The parasitic draw on engine battery, if it exists, and is not just a case of overwhelming undercharging, can be negated when parked by pulling off the ground cable from the engine battery, so at least it won't get pulled to dead as doornail status every night until it is figured out.
Draining a newish starter battery to dead as a doornail time and again , will have it unable to store enough energy to do its job in a very short period, and it is not the battery's fault, nor the retailer's.
Trebor English
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There are a bunch of relays. They are black plastic one inch cubes. Inside there is a coil electromagnet that turns on a switch. After everything has been off overnight they should all be cold to the touch. If one feels warm that means there is power to the coil, draining the battery. The owner's manual should tell what each relay is used for.
Touch the alternator. At zero rpm the field coil should not be getting current and the alternator should be as cold as everything else.
After pulling fuses to identify the drain, pull relays, one at a time, checking current drain.
Some relays are smaller, half inch plastic cubes.
If the result of fuse and relay pulling seems to point to a computer it needs more thinking before replacing more expensive parts.
Touch the alternator. At zero rpm the field coil should not be getting current and the alternator should be as cold as everything else.
After pulling fuses to identify the drain, pull relays, one at a time, checking current drain.
Some relays are smaller, half inch plastic cubes.
If the result of fuse and relay pulling seems to point to a computer it needs more thinking before replacing more expensive parts.
Trebor English
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Sorry, double post
Optimistic Paranoid
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katsmith said:
OK, in an earlier post, you mentioned that it was a 1988 Toyota, so there should be no engine computer to worry about.
I'm thinking that if you need a quick and dirty TEMPORARY fix, you should put one of these doohickeys on the battery, which will allow you to easily disconnect the engine battery when it's not running and hook it back up when you are ready to drive. With the battery disconected, there should be NO drain on it while you sit. The link is to Amazon, but you should be able to find one at most auto parts stores.
https://www.amazon.com/WirthCo-2010...31&sr=8-23&keywords=battery+disconnect+switch
This will let you head north to cooler temperatures. You need to find a shop that specializes in electrical diagnosis and problem solving, rather than just a grease monkey.
Or possibly you could rendezvous with someone from the tribe who has a meter and knows how to do simple diagnosis and would be willing to help.
Sorry, I'm still in NY, so I can't help in person.
highdesertranger
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I tried to find it explained in a simple way first one is text by Popular Mechanics,
http://www.popularmechanics.com/cars/technology/how-to/a5859/how-to-stop-car-battery-drains/
second a you tube video by "Eric the Car Guy"
look these over do you think you could do it? if not let us know. don't worry about the wire diagrams(schematics) yet. find the drain first we can help you from there.
is there anybody in the area that could help out? come on people speak up. where up north do you want to go? anybody in that area? highdesertranger
http://www.popularmechanics.com/cars/technology/how-to/a5859/how-to-stop-car-battery-drains/
second a you tube video by "Eric the Car Guy"
look these over do you think you could do it? if not let us know. don't worry about the wire diagrams(schematics) yet. find the drain first we can help you from there.
is there anybody in the area that could help out? come on people speak up. where up north do you want to go? anybody in that area? highdesertranger
DLTooley
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I do a hard disconnect on my house battery every night. Very simple **once** you get the habit.
