National Luna Split-Charge System Charging Issues?

dstock

Explorer
I've been discussing this issue in a couple of threads on here but seeing as how others are running into the same issues, I thought I start a dedicated thread.

I have the National Luna Split Charge system in my Jeep Rubicon paired with 2 Diehard Platinum batteries roughly 2 years old. The main battery is for starting and winching (so far hardly any winching) and the aux is for everything else, lighting, air compressor, phone/tablet/etc charging and running the fridge.

Everything worked great the first year or so, and then last May after a trip to Death Valley, the NL System would disengage, i.e. stop charging the aux battery, if the ambient temps got into the 80's and above. Sometimes this could occur just 20 minutes into my commute. When this occurs you cannot even connect the batteries manually through the controller. After several discussions with Paul from Equip the Intelligent solenoid was replaced and the problem seemed to be resolved. Then it occurred one more time although this time it recovered on it own. I had a spare controller, so I swapped that out as well and have not seen the issue occur again however we have not had the high temps as we did this past summer.

I have an Aeroforce gauge that monitors the voltage of the Jeep and it shows 14.0-14.3 when the Jeep is running so I believe the alternator is doing it's job. I will double check this at the batteries this evening.

Over the last month or so, I have noticed the overnight resting rate of both batteries dropping to 12.3 or 12.4. As far as I can tell there are no parasitic draws on either battery, and last night I disconnected the aux fuse box which powers pretty much all my add-ons so there would be no load on the aux battery and the result was the same.

With the NL system you can hear the solenoid engage and dis-engage, and that does appear to be working correctly, so I don't believe the batteries are staying connected when the Jeep is off.

It's for sure possible the aux battery was damaged during the under charging, but it doesn't explain why the main battery is showing the same behavior.

After posting around in a couple other threads, it appears I am not alone in this issue both with the NL system and Diehard Platinums and with the NL system and other batteries.

So possibilities I see are:

- NL system is not working properly and some how dragging down both batteries

- NL System ruined both batteries during malfunction

- NL system not up to the task of charging the Platinums

- Alternator issue

- Some sort of parasitic draw

- Both Diehards are just defective, I bought them at the same time so maybe a bad batch, it's certainly been known to happen.

- And of course some combination of one or all of the above

I've already gotten an education on charging, maintaining and the demands of these types of batteries in the "Odyssey vs Diehard Platinum" thread, good reading for those who haven't read it already, so I don't think we need to re-hash that here.

I'm mostly curious to see how many others are having this same issue with the NL system. I know of two others already who are experiencing the same thing and am hoping someone has come up with a solution even if it means ditching the NL system.

As for my situation, I'm going to start un-hooking things and see if it makes any difference in the overnight resting charge level and I will also bypass the NL system to see if the main battery will at least come back up. If nothing changes, I will be visiting Sears this weekend to have the batteries checked out.
 
Try some tests with an ammeter in series with each battery with the Jeep OFF as you would leave it for the night. I usually disconnect the (-) lead and insert the ammeter there. That will identify any parasitic draws. I really don't expect there to be any draws from the auxilliary battery under these circumstances, so I would start with that one. If you find a draw, it should be tracked down. If not, hook it back up to continue testing. The vehicle battery can be different. The current draw you see will depend on what needs power with the ignition off.

I would be concerned if you see anything over 200 milliamps through the vehicle's starting battery. You might try first with everything ie., batteries and NL system in place the way you normally use it. See if the current draw is going through the NL system. Then take the NL system out of the circuit and do the measurements again. If there are any draws, I would expect them to be the same. If they are the same, that probably tells you the NL system isn't contributing to the problem. Next, I would want to isolate the draws, start pulling fuses and watching the ammeter. Typical culprits are the keep alive on board memory for vehicle's computer, stereo system presets and alarm systems. As the current drops you are isolating the circuits that are drawing power. That's all I can suggest for starters. Using the ammeter will give you faster feedback than waiting to check voltage levels after unhooking something.
 

dstock

Explorer
Thanks, I will give that a shot. Think I will pick up a new meter with the clamp on feature on the way home, make things a little easier.
 
I don't know that there is a clamp on ammeter for DC. If you find one, pls let me know. For AC though, I found one at home depot that had some nice features from Klein Tools. I want to say it was around $50. It has been helpful to do some monitoring of AC equipment that I run off of an inverter in the truck and trailer. During those tests I have a DC ammeter in series with the negative inverter lead to the battery. Even if you can't use it for testing the NL system, you might find other uses for it. There is also a breakout plug that separates the conductors so you can easily clamp around them. That's about $15.
 
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Equipt

Supporting Sponsor Presenting Sponsor of Overland
Please tell me more about the issues you are experiencing with the National Luna system. I don't believe I am understanding the concern. From what I read above, the system seems to be working once we replaced a faulty Intelligent Solenoid. I have spoken to National Luna about concerns of temperature, and they haven't been able to replicate the issue in their facility. I would like to see what we can do to clear the air on this issue.

You will see a very minimal draw from the lights on the Dual Battery Controller. Insignificant day to day, but you should turn them off if you leave the truck for more than a week or so. It's only a few milliamps. The Intelligent Solenoid itself doesn't have a draw.

I use the Diehard Platinum batteries in my vehicles. Have for quite a few years. A resting voltage of 12.3-12.4V after a night of cooling down seems normal to me. I am not clear as to the concern here, and would like to better understand the issue.

Thanks,
 

dstock

Explorer
I don't know that there is a clamp on ammeter for DC. If you find one, pls let me know. For AC though, I found one at home depot that had some nice features from Klein Tools. I want to say it was around $50. It has been helpful to do some monitoring of AC equipment that I run off of an inverter in the truck and trailer. During those tests I have a DC ammeter in series with the negative inverter lead to the battery. Even if you can't use it for testing the NL system, you might find other uses for it. There is also a breakout plug that separates the conductors so you can easily clamp around them. That's about $15.

Sears has a clamp one for $60 that does DC up to 400 amps.
 
Well I just checked Sears and looked at the manual...and so it does! Now I hope the range goes low enough to measure milliamps with it.
 

dwh

Tail-End Charlie
So possibilities I see are:

- NL system is not working properly and some how dragging down both batteries

The system itself (normally) won't draw down the batteries enough to cause a problem. Very little power is needed to run the brain. The biggest draw from it would be when the solenoid itself is engaged, as it is an electromagnetic solenoid and could draw up to 1a - but only when energized to tie the batteries.

As I mentioned in the previous thread, if it is not isolating the batteries when it should, that can cause problems.


- NL System ruined both batteries during malfunction

Possible.


- NL system not up to the task of charging the Platinums

Not possible - the NL does not charge the batteries. It only ties them so they both get charged when there is something else (like the alternator) supplying charge current.



- Alternator issue

Possible, but unlikely. If it's pushing the bus voltage up to 14v+ and holding it there, then it's working.


- Some sort of parasitic draw

Very possible. The same effect can happen with a wire that is shorted, but not shorted enough to blow a fuse - just a bit of trickle drain. Those are tough to track down because they are usually intermittent.


- Both Diehards are just defective, I bought them at the same time so maybe a bad batch, it's certainly been known to happen.

Possible.
 

dstock

Explorer
Please tell me more about the issues you are experiencing with the National Luna system. I don't believe I am understanding the concern. From what I read above, the system seems to be working once we replaced a faulty Intelligent Solenoid. I have spoken to National Luna about concerns of temperature, and they haven't been able to replicate the issue in their facility. I would like to see what we can do to clear the air on this issue.

You will see a very minimal draw from the lights on the Dual Battery Controller. Insignificant day to day, but you should turn them off if you leave the truck for more than a week or so. It's only a few milliamps. The Intelligent Solenoid itself doesn't have a draw.

I use the Diehard Platinum batteries in my vehicles. Have for quite a few years. A resting voltage of 12.3-12.4V after a night of cooling down seems normal to me. I am not clear as to the concern here, and would like to better understand the issue.

Thanks,

Hey Paul,

The issue is over the last month or so my batteries have gone from a resting voltage of 12.7-12.8 to 12.2 - 12.4. It's the first time they have dipped that low overnight ever since I have had the system. Even when I had the solenoid issue the main battery never dipped to the halfway or below mark on the controller. I'm being told by several people on the board that Odyssey says the resting rate should be higher than the 12.3 range. I will give Sears a call tomorrow and ask them specifically what the resting rate should be just so we have that intel as well.

Having had the issues I did, my confidence was a bit shaken in the NL system. I am not saying that it is for sure the system and mentioned several times it appears to be working as it should currently. I'm just not sure why my resting voltage has dropped substantially so suddenly so I am looking at all the possibilities. I have changed nothing on my electrical system other than the solenoid. I am double checking everything to make sure my wiring, batteries and all are up to snuff so I don't get stranded out in the boonies.

On a side note, user "KellyM" is having the exact same issue I was having previously with the solenoid cutting out after 20 mins or so, you may want to get a hold of him. I mentioned to him this weekend that you were able to swap out my solenoid.

I did pickup a better a meter tonight on the way home to check for parasitic drain and I am not finding any so its leading me back to the same question, do I have a battery issue with the resting voltage or not?

I will say you have been nothing but helpful in dealing with my past issues, and the only reason I didn't contact you first on this one is I'm really not sure what is going on. I probably could have titled this thread better but I really wanted other NL users to chime in and either tell me I'm nuts and everything is working as it should or to share any issues they are having.

Appreciate your input as always.

Thanks.
 

dstock

Explorer
Well I just checked Sears and looked at the manual...and so it does! Now I hope the range goes low enough to measure milliamps with it.

It does and the highest I saw was about 120 milliamps, so back to what really is the resting voltage of the Diehard Platinum?
 

Equipt

Supporting Sponsor Presenting Sponsor of Overland
Thanks for your reply and kind words. We try our best to make things right. Things happen. It's how you handle them that matters.

The National Luna Dual Battery System is a very solid product. Equipt and National Luna will both stand behind this system, so if anyone is having an issue with their system please contact us directly and we will help you find a solution. Whether it comes out to be something on our end, an installation concern or a use issue. We're here to help, and get you back up and running. The title of the your thread had me quite concerned. The concept of automating the connection and isolation of 2 batteries in a vehicle is pretty straight forward, but can get really complex under the surface. Charging rates, discharge rates, connection and isolation values, draws on batteries, alternator output fluctuations on connection, new electronically managed alternator output, different vehicle manufacturers, battery capacity and design, different batteries, climate, use, and the list goes on. The National Luna system does a good job at managing all this, and is the messenger for the system too. All too often the finger gets pointed at the messenger. I am just here to have the messenger's back.

As most know, I am not on this forum as much as I should be. Often there are just too many balls in the air to see everything. I do remember a couple guys that were at the Overland Expo in 2013. They were driving a couple Disco IIs and one was having a real issue with his vehicle and the NL system, and their deduction was that high heat was making the NL system fail. I understand he wrote a thread on this as well. Anyway, it just so happened that the owner of National Luna had come over from South Africa to visit the show and these two gentlemen came through our booth with some questions. We all went out to the north 40 to diagnose the issue on the vehicle. Heat turned out to be a factor, but the NL battery management was working perfectly. The issue was that the there were a lot of demands on the system at any given time. Radios, lights, fridge, interior charging, stereo, etc. But the biggest culprit was the climate system constantly bumping on and turning off to keep the interior cool. The compressor kicking on is a significant hit, and with all the other systems taking their bite as well, the charging system was fighting to offset the draw and would at times drop below the 12.7V cutoff while the vehicle was running. At least that is the gist of what we found. We tested the NL system to connect and disconnect correctly, and it was working fine. I am not sure those findings were forwarded to the thread or not. A long story here for a short point. It is often the case that when the NL battery charging system is acting strangely, it is trying it's best to tell you something else with the system is not functioning properly.

I will try to reach out to KellyM and see what we can do for him. Thanks for the heads up. Does KellyM drive a Jeep as well? Forgive my ignorance here. I'm a Toyota guy. But I understand that the Jeeps have come out with an electronic charging system in their vehicle. Is that correct? The solenoid concerns seem to be originating on Jeeps specifically, and I am interested to know more about that system.

I had another thought on your reduction of resting voltage. Seasonal temperature change can effect the voltage capacity of a battery, especially as it ages. Are you in a climate that is going down in temperature as winter sets in? I am back in Utah, and know first hand that the winter cold can have an effect.

I use the Sears Diehard Platinum batteries, and often suggest them to customers. I think they are a great value. I put one into use in my 4Runner about 1.5 years ago when I put my NL system in. It's paired to the Panasonic battery new with the vehicle. I have a resting voltage of around 12.4V and honestly haven't thought much about it. It was higher when I bought it new, and expect it to decrease as the battery ages. I use the secondary battery quite a bit too, but charge it up well on the long distances I travel. I guess what I am saying is that I personally don't think 12.4V resting is out of range for a couple year old battery. You could drop by Sears and have them stress test them. Their warranty is one of the main reasons I use this battery. They could tell you if the batteries are fine or not, and may be able to test for parasitic draw. Great piece of mind.

Thanks,
 

shogun

Adventurer
Installed the system a few years ago in an older XJ. Within maybe the first year or so the controller stopped working and Paul changed out the circuit board and its been fine since.

The vehicle has been more down than not the past 6 months due to mx. A month or so ago after moving from one shop to another and parked for a couple weeks it was moved inside for work. No problems up to this point, then it was draining the main battery within 12 hrs. Charged the main and it would again deplete within a few hours. Moved back to general machanic and he began checking the current draw and disconnecting things. When he disconnected the controller the draw stopped. His conclusion was that the controller was the problem.

Seems odd to me because its never been a problem and the LEDs shouldnt draw enough to drain the battery. And I would also expect that much of a draw to generate some discernable heat. When we reconnected it it wasnt drawing the load and its been OK for the past few weeks. But I dont trust it much right now.

I emailed Paul to ask whether he has heard of any similar issues or might have any ideas. Still pending reply.

As to the OP, if I read the manual correctly, the system is not supposed to unparrallel the batteries until it gets to a specific voltage after shutdown. So if one battery is noticeably worse than the other, I would expect it to draw down the good battery until both reach that preset voltage before disconnecting.
 

Martyn

Supporting Sponsor, Overland Certified OC0018
Shogun, when we install NL Dual Battery Systems we advise the vehicle owners to turn the display off if they are not using their vehicles for a few days. This helps in maintaining the charge on the batteries. Turning off the display is easily done by holding down a button on the display for 5 seconds.
 

Equipt

Supporting Sponsor Presenting Sponsor of Overland
Hi Shogun,

First of all, my apologies for not responding to your email. I have scoured my inbox and can't seem to find your inquiry. Could you please forward it again, and I will respond right away.

Martyn is correct. Though the LEDs draw very little, over a long period of time the draw can add up to drain a battery. You can either turn the lights off as Martyn suggested, or you can disconnect the controller as well.

I would agree with you that the LEDs on the controller draining the battery in a matter of hours is probably not possible. But did disconnecting the controller cause something else to happen? Perhaps. The Intelligent Solenoid (IS) circuit board is a small self contained computer with a specific function. Monitor power and connect/disconnect within certain parameters. It is possible that as your vehicle sat and the battery slowly drained lower and lower, the IS monitored the voltage so low that it eventually did not recognize the connection any more. It does that. There is a cutoff voltage where IS circuitry does not register a connection any more, until a higher voltage is again acknowledged. Anyway, in this process of monitoring into the abyss, the software on the board can get confused. Much like your computer freezing up. And it needs to be rebooted. There is a small 12 gauge wire that comes directly out of the IS circuit board case, and it is supposed to connect to the main battery negative terminal. This is the control wire for the IS circuit board. The IS pulls power from the left side of the solenoid to the board and the 12 gauge wire to the negative terminal completes the circuit, bringing the IS to life and starts monitoring. The way you know this is all working correctly is if the IS "Timer Active" light blinks once. That is the "All systems checked and ready to work" blink. It has rebooted it's internal software, clearing out issues it has accumulated, has sensed two batteries connected, and is ready to do it's thing when asked.

So, back to disconnecting the Dual Battery Controller (DBC). If after the slow drain of the batteries the IS had it's electronic knickers in a pinch. Disconnecting the controller may have sent a signal to change the circumstances the IS was in. It was not a reboot as I mentioned above, but enough to influence a change in the IS status. I cannot say what the draw was that drained the battery so quickly. Were the batteries charged with the system still attached? Did the voltage of the charging go above the 13.1V threshold? Did the batteries connect through that charging process? Lots of factors at play. So I am not 100% sure there. It sounds like the DBC reconnecting has it back to working status, which is good news. If you want to verify that your system is working correctly, you can disconnect the DBC then disconnect and reconnect the small black 12 gauge wire. If this reboot gives you one flash from the IS, then things are right in the world there. Then connect the DBC and see what you get there. Monitoring should return to the controller immediately.

Here is the suggested practice when working with your battery system. This is any time you are making changes to your battery system, whether changing a battery/charging a battery/adding a fuse line or fuse block to the battery terminal/etc. First, disconnect the DBC from the IS. Remove it from the loop. Next, disconnect the small 12 gauge wire to the IS circuit board. Shut it down. Next, always disconnect the negative terminals first. This removes the possibility of an arc on the positive leads of the battery connections and an increased amperage shooting through the IS and DBC circuit boards. This is written in the installation instructions, but is sometimes overlooked. An arc through the positive leads can ruin the electronics connected to it. The majority of our issues stem from blown up circuit boards due to a positive lead arc. A customer will change a battery, or more often have a battery changed for them, and all of a sudden the DBC doesn't work any more. It isn't a matter of maliciousness, but of not understanding the effects of the termination. So negative leads are disconnected first and reconnected last. Then the 12 gauge black wire, then reconnect the DBC. Your IS and DBC will thank you for it.

I will look for your email. If I can't answer it, I will send it to the NL gurus and see what they say. They are pretty smart guys.

Thanks,
 

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