Dual batteries are almost a necessity for anyone who runs multiple accessories in their vehicle, and they provide you with the insurance that a flat battery won’t leave you stranded in the field.
Over the past 6 months I’ve been using the National Luna Dual Battery Monitor in our 2014 JKU Rubicon with very good results. It’s performed it’s task very well, and is simple enough that anyone with a basic knowledge of automotive electricity can install the entire system in a few hours.
Pros:
- Easy to install
- Controller is easy to read and use in the field
- Audible alarm for low voltage
Cons:
- Flimsy/cheap battery terminals
- Poor factory crimps
- Data cable may require drilling through some firewalls.
As I stated earlier, the National Luna is very easy to install, most of this can be contributed to the excellent directions they provide with their kits.
One of my favorite features though is their controller. The LED display is easy to read in all lighting conditions, the controls are clearly labeled, and they are easy to understand. The controller also features an audible low voltage alarm (can be disabled), and a timer override that allows you to put both batteries in parallel and override the programming.
On the flip side, I was surprised that such a high quality product would come with such poorly designed battery terminals. On multiple occasions I’ve had the battery terminals come off of my DieHard Marine Platinum batteries while driving down washboard, this isn’t a problem I’ve ever had with any other system. For $395 you would expect to get a higher quality component or even a military battery terminal.
Another issue that I’ve had is the poor crimps from the factory. I’ve had 2 fail on me over the past 6 months. The first was one of the wires that connected the solenoid to the controller and the second was one that connected the battery to the solenoid. Fortunately I was able to pull over both times and repair the crimps in the field, but I could see this being a problem for someone who doesn’t carry tools.
Finally I’ve spoken to a few people who have had to drill a larger hole through their firewall to fit the data cable. The connection on the end of the data cable will not fit through some factory holes and grommets, this isn’t a problem on the JK but it’s something to keep in mind before you start an install.
Overall though I’ve been happy with the product and the solenoid has proven to be 100% reliable. The shortcomings of the system can be readily fixed at home with off the shelf components, but if you spend more time on the pavement than in the dirt you’ll most likely never have to worry about the crimps.
No lie I always thought it looked a bit patched together or DIY. You defiantly wouldnt think its OEM
That’s probably because it’s sold as a DIY kit. National Luna supplies you with the components and instructions on how to get everything setup. It’s pretty much par for the course as far as Dual Battery monitors go.