Interesting No Start Issue

Romer

fatherofdaughterofromer
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I have the Hellroaring dual Battery system with two fairly new Sears Platinum AGM Batteries.

I had a problem a few weeks ago where I ran the fridge and couldn't start the vehicle, flipped it over to the backup and got just a click. More like a single clunk.

Thought maybe the backup problem was caused because I took the backup power cable to the primary battery rather than the starter like recommended.

Moved the cable to connect on the starter and it happened again

This time the primary was down to 12.6V, which shouldn't have caused any starting issues to begin with.

So I made sure the cables were tight and took the neutral safety connector of the tranny to make sure it wasn't corroded. It was a little gummy, but in pretty good shape and I cleaned it up and put it back on.

Ran a test over several days in between business trips

Ran the battery down to 12.5V - started fine

Ran the battery down to 11.5V - started fine

Ran the battery down below 10V and it did not start

So I switched to the backup battery and the lights and radio came back on. Tried to start it and the "thunk"

Measured 11.5V at primary battery with both batteries combined

So I know there is a voltage sensing switch and Robbie had suggested watching the voltmeter when trying to start it if this problem re-appears.

Voltage drop when starting shows it is not the cut off or neutral safety switch and the starter is getting voltage.

The voltage dropped with the key engaged

But wait, there is more

Holding the key in the engage position for a few seconds to read the voltage drop, the starter then kicked over.

Shut it off, tried it again and "thunk". Held the key in the on position and the starter would start to kick over after >7 seconds.

When it starts to kick over, it kicks over like normal not the slow pausing grind of a low battery.

I left the batteries connected for a few minutes and tried it again with the same result, so don't think the load of the low battery could be causing the delay

So I have ruled out the Neutral Saftey Switch and the Alarm voltage sense circuit. Pretty much leaves the starter. Course I changed the contacts about 40K miles ago
 

Romer

fatherofdaughterofromer
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I should mention that the two times I had the problem, I put a battery charger on at 25Amp fast charge for just a couple of minutes and it started right up.
 

Romer

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I should also mention, I have gone weeks without having a problem and it seems to start up pretty reliably after the thunk if I hold the key on. Don't know if it would have done that earlier though.

Primary battery has been recharged and is atrting fine (Normal) for now
 
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I should also mention, I have gone weeks without having a problem and it seems to start up pretty reliably after the thunk if I hold the key on. Don't know if it would have done that earlier though.

Primary battery has been recharged and is atrting fine (Normal) for now

If you have everything you need at the starter, it kinda has to be contacts or brushes.
The reason I'm stressing brushes is that my Honda Accord starter brushes gave up the ghost after 330,000 miles a week ago, thought for sure it was the solenoid, took it in to get looked at, surprise.....one of ground brushes isn't making contact anymore......and that you replaced contacts 40,000 miles ago.
:beer:
 
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There’s going to be some level of voltage drop in your set up by the time current reaches the starter. Depending on the wiring size, connections, plus the solenoid/isolator itself has it’s own inherent voltage drop, whatever that is. When you have it wired so that the current from the good battery has to pass through the dead battery before it reaches the starter, in addition to the existing resistance and voltage drop, the voltage that reaches the starter will only be the average of the two batteries, minus whatever other resistence is in the system.

It would be interesting to see what the voltage is at the starter when you have a low battery on one side and it wont' start right away. I'll bet its a lot lower than you might think.

Having a high amp charger on one or both both batteries, even for just a few minutes, raises the voltage dramatically, but doesn’t really add much to the overall amp capacity. However, if you have one good battery between the two, as long as the equalizing voltage is high enough, the combined amp capacity should be enough to turn over the starter for at least a couple of cranks, which apparently it does.

The "thunk" is probably the plunger in the starter trying to engage, which means the solenoid is getting enough voltage to close and allow contact between the batteries and the starter motor. The problem appears to be the starter itself not getting the voltage it requires to kick over the engine. It's possible that a clean new starter with less internal resistance in the brushes and contacts might operate at a voltage level that your current older starter cannot. Which might be why this is a problem now, but has never been before.

There's a couple of things I would do. First of all, I would change which battery powers what. I understand Hellroaring recommends having all the loads on the main battery and I'm guessing this is because their isolators really aren't that high of capacity. Especially the standard version. Hellroarding probably is mainly concerned about someone hooking up a winch or high wattage lights to the auxiliary battery, which would then require all of the current of the alternator to flow through the isolator to the auxiliary battery. With 75 amp isolator and higher amp alternator, such as a 150 amp unit, this could be bad news.

However, you could still leave the winch and lights and any high draw accessories attached the main battery to reduce the risk of damage to the isolator, but then hook up lower draw items that are most likely to be left on and drain the batteries, such as the refrigerator, to the auxiliary battery. This way, the auxiliary battery is much more likely to go dead and with the starter battery having a more direct route to the starter, it should start up no problem.

That would at least reduce the chances of the main battery going dead. To increase the chances of the auxiliary battery being able to start the truck if the main battery did die, I'd considering routing a VERY heavy gauge wire from the aux battery to the main battery via the starter, which I think is what Hellroaring recommends. Although such a set up trades the resistence of a dead battery for the restistence of having to use a longer wire through more connections.

Seems like the Hellroaring system has a lot of drawbacks compared to a very simple high amp solenoid system between two batteries, with all aux loads running off of the aux battery.
 
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landtank

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I had a lot of no start issues with my truck a year and a half or so ago. New brushes and all. I just swapped in a Reman and it's been fine. The contacts are onle a single wear point in those and not the only cause for this type of failure.
 

Romer

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Thanks for the response

There is 2AWG going straight from the backup battery (through the isolator) directly to the starter.

The starter failed when the primary was above 12V (batteries not connected)

When I drained the primary battery and joined the two batteries together, I measured 11.7V at the Primary battery. Remember, the path to the primary is to the starter via 2AWG from the backup and then to the Primary. What this means is that the voltage at the starter will be equal to or higher than measured at the primary batt when the backup is providing the load

Since it has failed at 12.6V, this isnt a Hellroaring problem, changing load will not impact that

I do see that my test to drain the primary battery may have not recreated the starter problem, but just showed how the dual connecting to the primary when dead may take a few seconds to engage the starter.

There’s going to be some level of voltage drop in your set up by the time current reaches the starter. Depending on the wiring size, connections, plus the solenoid/isolator itself has it’s own inherent voltage drop, whatever that is. When you have it wired so that the current from the good battery has to pass through the dead battery before it reaches the starter, in addition to the existing resistance and voltage drop, the voltage that reaches the starter will only be the average of the two batteries, minus whatever other resistence is in the system.

It would be interesting to see what the voltage is at the starter when you have a low battery on one side and it wont' start right away. I'll bet its a lot lower than you might think.

Having a high amp charger on one or both both batteries, even for just a few minutes, raises the voltage dramatically, but doesn’t really add much to the overall amp capacity. However, if you have one good battery between the two, as long as the equalizing voltage is high enough, the combined amp capacity should be enough to turn over the starter for at least a couple of cranks, which apparently it does.

The "thunk" is probably the plunger in the starter trying to engage, which means the solenoid is getting enough voltage to close and allow contact between the batteries and the starter motor. The problem appears to be the starter itself not getting the voltage it requires to kick over the engine. It's possible that a clean new starter with less internal resistance in the brushes and contacts might operate at a voltage level that your current older starter cannot. Which might be why this is a problem now, but has never been before.

There's a couple of things I would do. First of all, I would change which battery powers what. I understand Hellroaring recommends having all the loads on the main battery and I'm guessing this is because their isolators really aren't that high of capacity. Especially the standard version. Hellroarding probably is mainly concerned about someone hooking up a winch or high wattage lights to the auxiliary battery, which would then require all of the current of the alternator to flow through the isolator to the auxiliary battery. With 75 amp isolator and higher amp alternator, such as a 150 amp unit, this could be bad news.

However, you could still leave the winch and lights and any high draw accessories attached the main battery to reduce the risk of damage to the isolator, but then hook up lower draw items that are most likely to be left on and drain the batteries, such as the refrigerator, to the auxiliary battery. This way, the auxiliary battery is much more likely to go dead and with the starter battery having a more direct route to the starter, it should start up no problem.

That would at least reduce the chances of the main battery going dead. To increase the chances of the auxiliary battery being able to start the truck if the main battery did die, I'd considering routing a VERY heavy gauge wire from the aux battery to the main battery via the starter, which I think is what Hellroaring recommends. Although such a set up trades the resistence of a dead battery for the restistence of having to use a longer wire through more connections.

Seems like the Hellroaring system has a lot of drawbacks compared to a very simple high amp solenoid system between two batteries, with all aux loads running off of the aux battery.
 

Romer

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Been thinking about this today. How many times have we troubleshot a problem to see multiple things are going on and replaced the wrong thing

My initial starter problem was at 12.6V and have changed several things in the configuration since then. Cleaned up Neutral safety connector, tightened battery wires and cables and ran the backup battery with a 2AWG directly to the starter

My current test here in this thread was to validate the battery back-up system was working properly. Via voltage measurements I did verify that.

What if the several second delay for the starter motor to engage is normal behaviour based on the configuration

Then I may have fixed the problem already and nothing could be wrong with the starter.

So I simply disconnected the starter battery from the primary battery, switch to the backup battery and it fired right up. This shows the backup battery and controller can supply enough current to start the vehicle.

Now thinking bout the Dead battery test. When both batteries were combined at that point, the dead battery (10V) became a major load on the backup sucking current to recharge its cells until equliberium is reached. So when I tried to start it here, there were two loads and it took time for sufficient energy to give it the initial kick. Once a starter gets going, the back EMF reduces the load. It's the initial kick that takes a surge of current.

This would imply that there is nothing wrong with the starter.

This would mean that when switching on the aux battery in parallel, one should hold the key in the ON position or provide time for the batteries to equalize.

Course if it happens again, I will be able to quickly isolate it to the starter. But an intermittant starter problem and my dead battery tests results may be unrelated or made worse by the poor starter windings.

So have I been troubleshooting a problem I already fixed or has gone away fro the moment? I am thinking thats the case, but I learned some good lessons about how dual batteries work.

You guys don't mind while I talk to myself do you?:D
 
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Were you ever able to find the source of this issue. I am having nearly the same issue except I have a single Northstar battery.
 

LandLocked93

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Were you ever able to find the source of this issue. I am having nearly the same issue except I have a single Northstar battery.
Strictly speaking, this has to do with having 2/dual/front batts.
In your case, you're looking very closely at batt terminal condition, 4 chassis to block strap connections, and the starter.
Unless possibly your situation differs from the one above in any other way, by any other measure?
 
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Strictly speaking, this has to do with having 2/dual/front batts.
In your case, you're looking very closely at batt terminal condition, 4 chassis to block strap connections, and the starter.
Unless possibly your situation differs from the one above in any other way, by any other measure?
Thank you for responding. I was in the process of re reading the thread and figured out it was for dual battery set ups. My connections are spotless as is the battery terminal areas. I am leaning toward the NSS plug or wiring or the Starter at this point. Thanks again.
 

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