National Luna Split-Charge System Charging Issues?

dstock

Explorer
Hi,

ive been having this issue for over 2 years. finally took the time to figure it out last weekend. here is a copy of my email to Paul and NL. its the electronics in the solenoid controller that can't handle the under hood heat. hopefully they have upgraded electronics as I'd rather not have to buy another system.



Im hoping by putting both of you together in this email you can help. I have been dealing with this problem for over a year now. I contacted my US distributor and he sent me a new control board last year. I replaced it and have the same result. This is installed in a 1995 range rover classic with dual northstar AGM batteries. As with most older rovers, it makes a good amount of heat under the hood. At the suggestion of Paul I purchased a larger 200Amp solenoid as he felt that might be the problem. This made no difference. The symptoms rarely happen in winter but now that summer is here I can make it happen at will. Here is the scenario:

1) Drive truck down trails (dirt roads, etc) at slow speed when its hot out. Running the air conditioner will make it happen more frequently
2) After say 10 minutes or so the second battery will drop off charge. It will show full yellow on the display (but not green). The main battery will still show 3 green dots of charge.
3) If I pull onto a main road where I can get more vehicle speed (airflow) and drive for 10 minute or so I will hear the solenoid click and the aux battery will start charging again and show 3 green dots just like the main battery
4) If I come to a stop and idle, or start to drive slow (rock crawl, dirt trail, etc) It will stay connected for a few minutes and then drop off again. Pushing the button to manually bridge the 2 batteries does NOT bridge them together.

Last weekend it was very hot and my aux battery was starting to drain because the luna controller would not keep the batteries bridged as we were mostly on slow, dirt roads. I pulled out my multimeter and checked the voltage of the relay control wires of the luna controller when it was hot and I got ZERO volts. If I let the vehicle cool down and then check it (manual bridge button active for example) I get 12v. In desperation I ran a 12v feed directly to the control input of the solenoid. Now, no matter how hot it gets outside my batteries will stay bridged. This proves that the problem is the controller overheating and failing to deliver a 12v signal to my solenoid.

While my aux battery charges now this situation is far from ideal as I have to manually disconnect the solenoid power to break the bridge and my luna display has no control function and is just a voltage indicator now.

Do you have a solution for this? When I originally asked about the controllers overheating I was told that was impossible. Well its possible and it happens to both the boards I have. It has even happened to other people I know.

Please advise as this has been a thorn in my side for 2 years now.

Thank you!

I'm very curious to see a response from NL/Equipt on this as it appears these issues are not isolated to the Jeep JK.

It's an expensive system that shouldn't have this issue. Obviously, I've moved on to a Blue Sea ML-ACR which has performed flawlessly, but I'm not happy about the wasted money, nor the time spent trying to figure it out.
 

ndamico

Member
you don't have any voltage display with the ACR do you? i know it has the switch to bridge, disable, or auto but I do like the battery gauges on NL. Paul has been very responsive but Steven @ NL hasn't returned my emails. :(
 

dstock

Explorer
you don't have any voltage display with the ACR do you? i know it has the switch to bridge, disable, or auto but I do like the battery gauges on NL. Paul has been very responsive but Steven @ NL hasn't returned my emails. :(

There isn't any voltage display with the ACR, but the battery gauge isn't really worth it. If there is any load on the batteries, then you aren't getting a true representation of the voltage on the battery via the NL gauge. When the ACR is bridged, the switch lights up red for each individual battery, if there is an issue, it flashes to let you know.

I have an Aeroforce gauge that shows the jeep's charging voltage off the OBD2 port and then I added a dual battery monitor that shows % charged in the back of the Jeep next to the fridge so I can keep an eye on things when parked.

The other issue with the NL controller/gauge is that when it's not working right you have no way of joining the batteries. With the ACR you can manually flip a switch under the hood to join them.

I thought I would miss the NL display, but in reality, seeing the indicator lights on the bridging switch light up EVERY day without fail, I don't miss the display at all.
 

NexusD

New member
Hello everyone thanks for posting this! I too am having the same issues with NL solenoid and controlling unit.

My set is the same as Dstock's, but I use optima yellow tops.
My story:
Been running this set up for a few years now and it's been working great. All of a sudden On the first trip of this off roading season, on a Death Valley run the The control unit started wigging out and wouldn't read accurate battery outputs on both main and auxiliary battery. My main battery volt gauge was reading 14v. Once back home confirm that everything was working OK but the control unit still was not displaying accurately.

Driving around town in California heat I've noticed my alternator having issues trying to keep the secondary battery charged while running the arb refrigerator, all the while my main battery still reads 14 V.

Just this past July 4th the family and I we're on a camping trip for four days and my secondary battery only lasted a day. Through my testing at the campsite I found that the solenoid was working but when my main battery reaches 14v it would not charge my aux/secondary battery.

In order to keep juice in the secondary battery I had to use jumper cables to go from my main battery to the aux/secondary battery in order to keep the secondary charged. All the while the vehicle is running.

So here I am looking to figure what's going on before I trash the whole NL product. In my second vehicle I run the cheap t-max unit and I've had no issues for over a year.

It really makes me mad that a reputable company puts out garbage at a higher price and will not stand behind their products. Seeing how I've used the product for about 4 years now I'm way out of warranty.
 

dstock

Explorer
Hello everyone thanks for posting this! I too am having the same issues with NL solenoid and controlling unit.

My set is the same as Dstock's, but I use optima yellow tops.
My story:
Been running this set up for a few years now and it's been working great. All of a sudden On the first trip of this off roading season, on a Death Valley run the The control unit started wigging out and wouldn't read accurate battery outputs on both main and auxiliary battery. My main battery volt gauge was reading 14v. Once back home confirm that everything was working OK but the control unit still was not displaying accurately.

Driving around town in California heat I've noticed my alternator having issues trying to keep the secondary battery charged while running the arb refrigerator, all the while my main battery still reads 14 V.

Just this past July 4th the family and I we're on a camping trip for four days and my secondary battery only lasted a day. Through my testing at the campsite I found that the solenoid was working but when my main battery reaches 14v it would not charge my aux/secondary battery.

In order to keep juice in the secondary battery I had to use jumper cables to go from my main battery to the aux/secondary battery in order to keep the secondary charged. All the while the vehicle is running.

So here I am looking to figure what's going on before I trash the whole NL product. In my second vehicle I run the cheap t-max unit and I've had no issues for over a year.

It really makes me mad that a reputable company puts out garbage at a higher price and will not stand behind their products. Seeing how I've used the product for about 4 years now I'm way out of warranty.

Agreed, it's very frustrating.

You don't mention whether you have solar backup for your AUX battery but if you don't I would highly recommend it, With the temps we've been seeing in California of late, no way the AUX battery is going to keep up for more then a day when ambient and fridge temps are 60+ degrees apart.

Also, if you feel your AUX battery was deeply discharged, I'd put it on a battery charger to get it properly back up to spec, don't count on the alternator to fully recharge it after a deep discharge.
 

NexusD

New member
Agreed, it's very frustrating.

You don't mention whether you have solar backup for your AUX battery but if you don't I would highly recommend it, With the temps we've been seeing in California of late, no way the AUX battery is going to keep up for more then a day when ambient and fridge temps are 60+ degrees apart.

Also, if you feel your AUX battery was deeply discharged, I'd put it on a battery charger to get it properly back up to spec, don't count on the alternator to fully recharge it after a deep discharge.
Thanks dstock for posting this!
This has been a great post and learning experience about batteries. Putting all the battery talk aside, the true issues is the NL setup. I'm going to reach out to Paul this week to see what my options are, I'm 90% sure I'm junking the NL set up. I'm looking at redoing everything and going with ctek or blue sea acr.
I'm shopping for a 200w solar setup.
I'm bummed that there isn't a solution to the NL setup
Thanks again
 

paranoid56

Adventurer
There isn't any voltage display with the ACR, but the battery gauge isn't really worth it. If there is any load on the batteries, then you aren't getting a true representation of the voltage on the battery via the NL gauge. When the ACR is bridged, the switch lights up red for each individual battery, if there is an issue, it flashes to let you know.

I have an Aeroforce gauge that shows the jeep's charging voltage off the OBD2 port and then I added a dual battery monitor that shows % charged in the back of the Jeep next to the fridge so I can keep an eye on things when parked.

The other issue with the NL controller/gauge is that when it's not working right you have no way of joining the batteries. With the ACR you can manually flip a switch under the hood to join them.

I thought I would miss the NL display, but in reality, seeing the indicator lights on the bridging switch light up EVERY day without fail, I don't miss the display at all.

I also love this setup, but I have also killed two ACRs. strangely with water. Both times i opened it up and saw water in them. I have mine located under the hood next to the batter, so i have no idea how water got in them. Its not like it rains a lot in San Diego, and i have not gone though any deep water lol
 

dstock

Explorer
Thanks dstock for posting this!
This has been a great post and learning experience about batteries. Putting all the battery talk aside, the true issues is the NL setup. I'm going to reach out to Paul this week to see what my options are, I'm 90% sure I'm junking the NL set up. I'm looking at redoing everything and going with ctek or blue sea acr.
I'm shopping for a 200w solar setup.
I'm bummed that there isn't a solution to the NL setup
Thanks again

Glad you found the thread useful, agreed lots of good input from lots of people.

I'm guessing 200amp solenoid version and move it out from under the hood is the only solution for the NL setup. I wasn't interested in running large gauge wire to other places in my vehicle, kind of defeats the purpose. Still, I'm not sure I would trust it at this point.

I considered the CTEK setup also but it seemed overly complicated and wouldn't easily fit under the hood.

The BlueSea ACR has been great so far and super simple, I'm really pleased with it.

Good luck, report back on your findings!
 

dstock

Explorer
I also love this setup, but I have also killed two ACRs. strangely with water. Both times i opened it up and saw water in them. I have mine located under the hood next to the batter, so i have no idea how water got in them. Its not like it rains a lot in San Diego, and i have not gone though any deep water lol

That's bizarre, I have mind located there also. Which model ACR?
 

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