P500 Battery Isolator

[ScottA58]

My 2025 520 is supposed to be delivered in August and I am in the planning stages for what I am going to add to it. The accessories I will be installing that require power are a Warn Axon winch, front LED lightbar, and rear cube lights. I plan on installing a second battery under the hood.
How many of you guys with a second battery have it wired to an isolator?
I have been in a low voltage industry for 40 years, so I see both some pros and cons of using an isolator when wiring in these accessories. Those who are using an isolator, please tell me why you installed it and those who just wired the batteries together in parallel, why did you go that route.
TIA

 

[Admin]

 

[Hondasxs]

Many of us run isolated systems.
So you're considering isolated vs. parallel and why.

For the 500, the use case is totally different than the Pioneer 1000 and Talon.
With the 1000, the goal of an isolator system is to keep the primary battery at 12v+ at all times.
As such, when you pull the winch load, the isolator disconnects and leaves the primary alone, leaving 12v for the "system".
The 500 doesn't really have all that much electronics to require this.

With that said, you will have to make that decision. I guess a few things come to mind.
- How often will you be riding alone? = consider isolated.
- How often will you be using key-off power? = consider isolated.
- Do you expect to use your winch about every adventure out? (and you answered no to the above)... then parallel.

No issue either way, really.

 

[Scoop]

If I go through the hassle and expense of adding a second battery wired in parallel into any type of motor vehicle that, from the factory, comes with only a single battery, there's no way I'm NOT going to install an isolator while doing so. The only way I would NOT do that would be if that vehicle would never be far from home, such as being used on a farm, ranch, or otherwise not in the middle of BFE with a long walk back to civilization.

The purpose of the isolator is to preserve the primary battery in the event something happens to the secondary battery. While this could be something that's willingly but unintentionally (e.g., running down the battery while listening to the radio or using a high-draw device while the key is off), it could also be something unexpected like a short in the wiring or battery that would, without an isolator, drag BOTH batteries down.

You're adding new/additional points of failure to your electrical system, and a failure of any of these new points of failure could not only bring down your auxiliary battery, but your primary as well.

Personally, I consider it little more than "cheap insurance".

 

[trigger]

Makes sense on a P1 but it's not necessary on the 500. Been running two in parallel for over 8 yrs, that's using the winch for plowing every winter, having a stereo that'll split your skull and about every other electronic gizmo available.
As for having a short when out in the middle of BFE by yourself, that can happen with a single battery as well, fuse your accessories and carry a jump pack... it's cheap insurance.
As for running the battery down listening to the radio with the key off... duh... but again use the jump pack.

 

[Scoop]

I'm sure 99% of the buggies with dual batteries could likely get away with NOT running an isolator, too. But then we'd have to find something else to waste our money on! 😆