deep cell battery cut-off switch

[SternWake]

I would do the van battery first then the house battery.

But, IF the isolation device used has failed closed, both batteries are in parallel and both will share the charging current from the charger making which battery the charger is attached to of little overall consequence.

 

[Ella1]

Thursday Feb 16, 2017

Again, thanks to all of you for your help and guidance.

The CRVL member came over to see if there was a relatively easy way to determine the problem(s). He says he is not very knowledgeable, but between reading and watching YouTube videos, he was willing to give it a go.

The batteries were in okay shape, he said. The auxiliary marine battery was at 12.4 volts, but he said to hold on to it until I kill it. That one is only used for low wattage items. The starting battery was 12.7v, but that wasn't unexpected as it's only a couple weeks old. Then he checked for a parasitic drain. He said that only 0.18 milliamps was going through and that anything under 50ma was fine.

Next, he checked the alternator. That was fine too. So he went on to check the voltage regulator. When I ran up the rpms, he had me turn on the lights, windshield wipers and air conditioner. The engine started to sputter and drop out. And he said that the alternator couldn't keep the voltage above 12.4v with the load and the increased rpms.

He said that he might be very wrong as he doesn't have a lot of experience. He said that replacing the voltage regulator should have been investigated at some time, especially since I've been having these symptoms for (???) years. Especially when the alternator was replaced a couple of years ago. I told him that they might have checked it or replaced it the, but I don't know. But over the years, I have asked them if there could be a problem with something electrical besides the alternator.

But, we'll see what the true problem is when I go to get it looked at.

As far as the auxiliary battery, it was charging. The diode had been replaced at some time as the old one is sitting right next to the new one. But, my friend was very concerned that the wires coming into from the alternator and going out to the inverter was about 14 gauge SAE. He was surprised and told me that I shouldn't run more that a couple of hundred watts off of it. I never have. He said that since I've been using it for 16 years, that if it ain't broke don't fix it.

Especially since if I decide to travel more, I may put in a solar set up. At that point, he says that a new cable should be run back to a golf cart battery bank, just bypassing the current aux battery system. I really need more than the bare bones, poor quality setup that I have now.

He wasn't too impressed with the aux battery wiring. Then he said that his suppositions about the quality of work on the installer was confirmed when he found out that when, at the same time they installed the batteries, they installed two 12 volt outlets in the back of my van. Well, you would assume that since they put in the aux battery and inverter, that they would use the same system to power the cabin 12 volt battery outlets. But, no! The 12 volt outlets are hooked up to the engine battery.

So, the tentative diagnosis is a faulty voltage regulator, he said. And, since I don't drive much at all, I should put a battery tender on both batteries. He suggested a mountable, waterproof NOCO 2 bank 8 amp charger for $100. He suggested that I ask other members here if that will work.

So, my friend is asking for input. What do you all think or suspect? Do you think that we should suspect the voltage regulator? He says that as an outright amateur that he may be completely off base.

I'm sorry this is so long. It took me much longer to write this than the total of ~20 minutes that he took to go through things. I am very grateful for the time and work this member volunteered to do for me, a complete stranger. I will pass it on as I am able. God bless you all and keep you safe.

Thank you

 

[SternWake]

What type brand and year of vehicle is this again?

I ask as there are 3 possible locations of the voltagre regulator

Internal to the alternator
External, mounted on firewall
External, inside of engine computer.

The fact that it could not maintian voltage with all the loads on, is not an indictment of the voltage regulator. My own well wired and very capable charging system cannot maintain voltage at idle with all the DC loads turned on, in addition to a depleted battery, and that is with the voltage regulator seeking 14.8v. The alternator is simply not powerful enough spinning at low rpm to maintain voltage.

But the engine conking out, sagging under the larger electrical load is not good. it might point to the engine to battery ground cable being compromised, or the cable from alternator to engine battery, either not being able to pass all the amperage needed.

I'd prefer to know what type of 'isolator or diode or solenoid ' Make and model number is actually used before making any further recommendations, but the 2 bank Noco would likely be fine to fully recharge after an outing, and maintain the batteries full inbetween outings.

14awg from alternatort to diode isolator( or ANY similar device) to house battery is overwhelmingly inadequate for anything close to proper recharging of depleted house battery

Such a battery is Doomed to premature capacity loss and a short lifespan if that is the only charging source it ever sees.

 

[Ella1]

Thanks, This is a 1995 Chevy Astrovan.
How do we determine if the grounds are bad?
I think the voltage regulator is behind the alternator on the firewall.

About the only things I run when driving is either the heater or ac, and the windshield wipers. I rarely (almost never)
use the radio or interior lights or have anything plugged in. (cell phone on occasion if it wasn't charged at home) I seem to remember a drop in power when the ac is on and I turn on the headlights. Stopping at a light, I used to turn the ac off.

After reading your response, it sounds like an auto electric place would be better than a regular shop.
Or would you think an rv place would be better?

 

[Ella1]

I think you said the wires to and from the house battery should be upgraded.
Is that correct?

 

[SternWake]

Rock Auto says all  drop in replacement alternators for a 1995 astro have a voltage regulator internal to the alternator, not an external regulator.


That does not mean the previous owner has not installed an externally regulated model and added an external regulator however, but it seems highly unlikely.

The blower motor can draw as much as 20 amps on higherst speed, Not sure what an AC clutch requires, but could be 15 amps?  Headlights and running lights are about 15 amps

Interior lights and cell phone charger are a non issue in terms of load on alternator.

If there is any white or green corrosion on the battery terminals then I recommend replacement.

The grounds basically need to be removed, filed/sanded/wirebrushed spotlessly clean and retightened.  One can not visually detect a bad ground, unless it is obviously loose and growing cauliflower.

There will be a fatter cable going from alternator (+) stud to engine battery, likely with a fuse somewhere in line.  This cable could be compromised anywhere along its routing.  The fuse holder could also be a culprit.

At this poit I believe the engine sagging under high electrical loads is the main probelm with your batteries charging poorly a direct causation of a Poor Original charging curcuit, that is further burdened by depleted batteries.

There will be a few wires/cables that go from engine battery (-).  One should be to the firewall/ fenderwell, the other should go to the engine block.  These two cables would be the first thing I check, then I would find and follow the cable from alternator(+) to battery and look for any suspicious connections or burnt wire insulation.  

I always recommend upgrading wire/cable when charging depleted batteries is a consideration,  The cables which came with vehicle from the factory were the thinnest they could possibly get away with.  When electrical loads increase ( like with an additional battery added) they become inadequate.

 

[Ella1]

Monday 5:30 PM I just talked to Al. He asked a few questions, then basically said the first thing he'd recommend is replacing the 2 yo marine battery with the same make as the main battery. He asked about a manual switch that the installers should have put in to change the current from one battery to the other, that I know nothing about. If it doesn't have that , it should have this other one—a battery sensitive switch. He will install the battery charger.
He said he worked on rvs back east, hasn't for a while.
He'll check everything, he does not mark up for parts, will not do anything without okay from me.
Price per hour is better than the other man I talked to. He seems more approachable, that questions will be answered with respect, explanation, and even humor.
He's closer, and will get me home.
He's busy, it'll be almost two weeks before he has an opening for me.

I think rather than getting another 12 volt, I'll price two 12 volt deep cell batteries instead.
I did not feel talked down to.

I had my information written, your suggestions written and translated so it sounded like it was coming from me, and several questions. He listened to a few and answered well, I think. He had not finished his day, I didn't want to keep him gabbing at his dinnertime.
Again, thank you all for your guidance.

Because he IS so busy--basically a one man shop with a bit of help at times--I'll probably go to a regular garage for immediate stuff. I think I'll try someone else. This is the third--and from what Al said, a fourth time my other failed me. I can't afford them anymore.

 

[Ella1]

"then basically said the first thing he'd recommend is replacing the 2 yo marine battery with the same make as the main (2 week old) battery. "

I woke up thinking about that. That doesn't make sense, even to me. I won't be going to him...

I have an appointment with an auto electric place in two weeks.

Tell me this: Will diagnosing the problem with their computers give the same results as with volt and amp meters? I did tell them it needed eyeballs and fingers on the system too.

 

[SternWake]

"then basically said the first thing he'd recommend is replacing the 2 yo marine battery with the same make as the main (2 week old) battery. "

I woke up thinking about that. That doesn't make sense, even to me. I won't be going to him...

I have an appointment with an auto electric place in two weeks.

Tell me this: Will diagnosing the problem with their computers give the same results as with volt and amp meters? I did tell them it needed eyeballs and fingers on the system too.

If the isolation device is working properly there is no need for the batteries to be of the same type/age/make.

Whether the battery in question needs to be replaced anyway is certainly a possibility.  Age does not matter when it has been sitting undercharged or otherwise abused 

If they hook up an OBD1 reader all it will say, AFAIK, is whether voltage when engine is running is adequate or not.

People seem to think that computers diagnose vehicle issues, but all they do it point to sensor readings that are out of whack and these clues and experinece lead the mechanic as to why the sensor readings are out of whack.

It is not as if the OBD1 reader is going to say charging voltage low due to excessive friction/resistance in the ground path.  it will say voltage low, and the tech needs to then figure out why through more tests and the process of elimination, with a big helping of experience on the vehicle/brand experiencing the issues.

Nothing pisses off a mechanic more than a driver who thinks that a computer diagnoses any possible issue and all they are, are parts replacing monkeys, though many of them are just that, as they have no ability to follow clues.

 

[Trebor English]

"Their computers" are not connected to anything to diagnose anything beyond the van engine and it's alternator. It cannot tell if there is any additional battery or wire or fuse or disconnect switch, good or broken.

 

[Ella1]

Trebor, thanks for your response. I know this will get adjusted.

 

[Ella1]

Hi, All,
My van is at the auto electric garage today.
The mechanic just called to tell me it has two isolators, both near the auxiliary battery. One is disconnected, the other barely working, so the alternator is barely charging it. I don't know if he meant it was not properly charging the main battery either.
The problem, he thinks, is that the wiring is so messed up that after it gets corrected, he thinks that might solve the electrical problems, that the new noco charger probably won't be needed.
But I have it, I think I'll have him install it anyway.
Now he's looking for parts.
I don't know if I get it back today or not.

SternWake and Trebor, you are so right, my regular mechanics don't know about electrical. They've been blaming me for the van's problems. We talked about my driving, and he repeated, "lets get this wiring working correctly, I don't think you'll need the charger. Your driving is not the problem"

 

[Alcatraz]

I would change mechanics if he thinks that installing a cut off switch is to complicated/expensive.
I have no one to recommend but that is a pretty easy job to do.