---
product_id: 7065661
title: "1213.1241 20092 Battery Doctor 125 Amp/150 Amp Battery Isolator , Black"
brand: "wirthco"
price: "VT55976"
currency: VUV
in_stock: true
reviews_count: 8
category: "Wirth Co"
url: https://www.desertcart.vu/products/7065661-1213-1241-20092-battery-doctor-125-amp-150-amp-battery
store_origin: VU
region: Vanuatu
---

# 150A peak amperage power IP62 water resistant for marine use Automatic dual battery charging 1213.1241 20092 Battery Doctor 125 Amp/150 Amp Battery Isolator , Black

**Brand:** wirthco
**Price:** VT55976
**Availability:** ✅ In Stock

## Summary

> 🔋 Stay charged, stay unstoppable — power your adventures with confidence!

## Quick Answers

- **What is this?** 1213.1241 20092 Battery Doctor 125 Amp/150 Amp Battery Isolator , Black by wirthco
- **How much does it cost?** VT55976 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.vu](https://www.desertcart.vu/products/7065661-1213-1241-20092-battery-doctor-125-amp-150-amp-battery)

## Best For

- wirthco enthusiasts

## Why This Product

- Trusted wirthco brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Powerhouse Performance:** Handles up to 150 amps peak for robust battery management
- • **Surge-Protected Safety:** Built-in overcurrent and surge protection safeguards sensitive vehicle electronics
- • **Marine-Ready Durability:** Water resistant IP62 rating ensures reliable use even in wet environments
- • **Smart Dual Battery Control:** Automatically charges auxiliary battery while isolating starter battery
- • **One-Touch Jumpstart Override:** Manual override lets you parallel batteries instantly for emergency jump-starts

## Overview

The WirthCo Battery Doctor 125/150 Amp Battery Isolator is a compact, water-resistant (IP62) electronic device designed to manage dual battery systems in vehicles. It automatically charges an auxiliary battery while isolating the starter battery to prevent drain, supports manual override for jump-starting, and includes surge protection to safeguard modern vehicle electronics. Ideal for marine and automotive use, it delivers up to 150 amps peak amperage, ensuring reliable power management for professional and adventure-ready setups.

## Description

WirthCo Battery Doctor Battery Isolator - 125/150 peak amperes is a state-of-the-art, fully automatic, dual battery controller that is suitable for any vehicle with an auxiliary battery. Smaller and lighter than other standard battery isolators, the battery isolator employs electronic switching control technology. High-performance electronic isolator allows you to charge two batteries from a single alternator, and keeps the starting battery isolated from the second battery. Also, with a single push of the override/reset button, you can change the batteries to parallel mode for jump-starting. This is water resistant; making it suitable for marine use (IP62). It includes a mounting bracket and over-current and surge protected for vehicles with electronic systems. For over 30 years, WirthCo has been a prime manufacturer of practical products for making life easier and safer. California Prop 65 - Warning, This product contains chemicals known to the State of California to cause cancer, birth defects or other reproductive harm.

Review: Blue charging light never came on, returning product. - No Luck so far making this device operate. I have a 1971 VW Bus and wanted a aux battery for accessories without draining the starter battery. Installation was easy and followed very easily. I have a 7 month old starter battery. Once I hooked in a ground wire from the aux battery to the frame the red blinking light turned solid red as stated in the instructions. I start the vehicle and the blue charging light never came on. Thought, well I will drive around and see what happens. I found out that my starter battery kept draining while the aux batter remained charged...but still no blue light.Basically it has killed my (fairly new) starter battery and I got it replaced - did find out on numerous occasions that the jumpstart feature works GREAT!!! New starter battery in, same thing exactly as written above. Back to square one. Called tech support, "Tim" was very helpful and said it may be that the circuit board is defective and to return it. I did and waiting on a replacement. I hope it works, but the new starter battery has probably suffered some damage from being discharged frequently. Tech support also mentioned that the unit will not work on a positive grounded vehicle and suggested that may be my issue. No, the VW Bus has a negative ground system....but people who may have a European car that has a positive ground system, this will not work. I will update once I get the replacement, but just don't think it is going to work but hoping for the best. The instructions said it goes into charging mode when the starter battery is above 13.4v....well, that is probably the problem as even the starter battery read 12.8 volts BRAND NEW. Not too sure how to get it up to 13.4? Really disappointed this did not work for me so far and caused a lot of troubles along the way. Looks like many people had a good experience. ****UPDATE**** Batteries, mostly the starter battery was low. Decided to put it on a charger while still in the vehicle. Next morning to my surprise the blue LED light was on! Turns out it is working properly, I was just not getting the proper voltage due to a pre-existing alternator condition. Got the alternator wiring corrected and this product works as described and like a champ!
Review: Exactly what you need - If you’re running a second battery, I’d highly recommend getting this. You want to hear it, here it goes. This is a smart battery isolator, charger, and jump starter all rolled into 1 palm-sized device. When installed correctly, you can run power into your secondary battery without affecting the main starting battery. The device stays on for less than a minute between shutting off your vehicle and running parallel with your main battery. So there will be a small parasitic draw for balancing both batteries during that minute. This compact device has 3 connection points, main battery, secondary battery, and pre-wired ground. I highly recommend using a fused 4 gauge or higher cable from the main battery with the fuse or breaker fuse closer to the main battery, and a fused same gauge or lower wire out to your accessories from your secondary battery. Following the instructions I realized it wasn’t charging my secondary battery and wondered why. I later found that my main battery was faulting and after charging it for 8 hours didn’t hold a charge past 64%. With that said, it will only charge your secondary battery IF your main battery is charged past 13.4V. Once I got my main battery sorted (new one), everything was working as it should be. FYI, if either your main or secondary battery loses connection, the isolator will shut off by default. I tried to run the isolator in override mode to swap out the main battery without losing power, but found out that it simply shuts itself off. It’s a good thing. I also found out that this thing has a built in voltage spike regulator, similar to a power conditioner. But I wouldn’t consider it to be a conditioner either. Before this, I had an 80A Stinger battery isolator/relay between the main and secondary battery. I also had a 150A fuse breaker between the secondary to my rear fuse box for my accessories that kept tripping only during vehicle startup without any accessories ON. Battery to battery was fine over 80A relay, but the surge of power introduced by the alternator kept tripping my 150A breaker. After installing this, I had my 250W light bar ON running out of the secondary battery without tripping the breaker during startup. So in short, it can detect power spikes and send the correct signals. I highly recommend this if you’re into the whole secondary battery and trying to stay within budget. What’s $53 compared to potentially burning your entire electrical system (undercharging or overcharging) or getting stuck in a remote place without jumper cables. Hopefully this helps you think about what this thing is actually doing and what you’re protecting. I have a truck with a V8 5.0L engine and a stock 150A alternator, and the 125A/150A works for me. V6 and smaller motors with smaller applications can easily use 75A/100A system.

## Features

- Water resistant (IP62) - suitable for marine use
- Priority charging for starting battery. Not suggested for Lithium Batteries.
- Automatically charges auxiliary battery
- Manual override for starting battery
- Over current and surge protected for vehicles with electronic systems

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0058SGDFK |
| Amperage | 150 Amps |
| Best Sellers Rank | #220,375 in Automotive ( See Top 100 in Automotive ) #844 in Battery Chargers |
| Brand | WirthCo |
| Customer Reviews | 4.5 4.5 out of 5 stars (820) |
| Date First Available | June 30, 2011 |
| Is Discontinued By Manufacturer | No |
| Item Weight | 15.2 ounces |
| Item model number | 1213.1241 |
| Manufacturer | WirthCo |
| Manufacturer Part Number | 010054200929 |
| Model | Battery Isolator, 125A |
| OEM Part Number | 20092 |
| Product Dimensions | 5.1 x 5.7 x 2.3 inches |
| Voltage | 12 Volts |

## Images

![1213.1241 20092 Battery Doctor 125 Amp/150 Amp Battery Isolator , Black - Image 1](https://m.media-amazon.com/images/I/51mq+S789LL.jpg)
![1213.1241 20092 Battery Doctor 125 Amp/150 Amp Battery Isolator , Black - Image 2](https://m.media-amazon.com/images/I/61sdw8j-xHL.jpg)
![1213.1241 20092 Battery Doctor 125 Amp/150 Amp Battery Isolator , Black - Image 3](https://m.media-amazon.com/images/I/71BoBxqrwQL.jpg)
![1213.1241 20092 Battery Doctor 125 Amp/150 Amp Battery Isolator , Black - Image 4](https://m.media-amazon.com/images/I/81buYNhuqlL.jpg)
![1213.1241 20092 Battery Doctor 125 Amp/150 Amp Battery Isolator , Black - Image 5](https://m.media-amazon.com/images/I/81msuQ3BxKL.jpg)

## Questions & Answers

**Q: Can this be connected to a car battery then to a lithium battery pack for the purpose of keeping the lithium’s charged? Lithium for car amps**
A: No.  Lithium batterie$ need a $pecific charge controller. ($$$)

**Q: does the blue light stay on**
A: The blue light indicates that the primary battery is connected to the alternate battery and charging. This happens when (1) the vehicle's ignition is on and (2) the primary battery is being measured at 14V or higher.
Also, after turning off the ignition there is a delay of less than a minute before the batteries are isolated. The blue light will remain on until completed

**Q: i bought this three months ago.  the battery continues to drain.  always stays at 11.7 v.  i dont know if thing is broken or what.  what do i do?**
A: I would not continue to let the batteries drain to 11.7 Volts.    Never let you battery bank get lower then 11.9 Volts.  I would replace your battery isolator.

**Q: Can I use this with a 200 amp alternator or will it hurt the unit**
A: This unto will work fine. Your alternator may be rated for 200 amps. That rating is right before is burns up. There are other loads in your car that will take power while it is running. There is no way your alternator will push 200 amps to your battery.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Blue charging light never came on, returning product.
*by N***. on April 22, 2018*

No Luck so far making this device operate. I have a 1971 VW Bus and wanted a aux battery for accessories without draining the starter battery. Installation was easy and followed very easily. I have a 7 month old starter battery. Once I hooked in a ground wire from the aux battery to the frame the red blinking light turned solid red as stated in the instructions. I start the vehicle and the blue charging light never came on. Thought, well I will drive around and see what happens. I found out that my starter battery kept draining while the aux batter remained charged...but still no blue light.Basically it has killed my (fairly new) starter battery and I got it replaced - did find out on numerous occasions that the jumpstart feature works GREAT!!! New starter battery in, same thing exactly as written above. Back to square one. Called tech support, "Tim" was very helpful and said it may be that the circuit board is defective and to return it. I did and waiting on a replacement. I hope it works, but the new starter battery has probably suffered some damage from being discharged frequently. Tech support also mentioned that the unit will not work on a positive grounded vehicle and suggested that may be my issue. No, the VW Bus has a negative ground system....but people who may have a European car that has a positive ground system, this will not work. I will update once I get the replacement, but just don't think it is going to work but hoping for the best. The instructions said it goes into charging mode when the starter battery is above 13.4v....well, that is probably the problem as even the starter battery read 12.8 volts BRAND NEW. Not too sure how to get it up to 13.4? Really disappointed this did not work for me so far and caused a lot of troubles along the way. Looks like many people had a good experience. ****UPDATE**** Batteries, mostly the starter battery was low. Decided to put it on a charger while still in the vehicle. Next morning to my surprise the blue LED light was on! Turns out it is working properly, I was just not getting the proper voltage due to a pre-existing alternator condition. Got the alternator wiring corrected and this product works as described and like a champ!

### ⭐⭐⭐⭐⭐ Exactly what you need
*by D***W on July 24, 2017*

If you’re running a second battery, I’d highly recommend getting this. You want to hear it, here it goes. This is a smart battery isolator, charger, and jump starter all rolled into 1 palm-sized device. When installed correctly, you can run power into your secondary battery without affecting the main starting battery. The device stays on for less than a minute between shutting off your vehicle and running parallel with your main battery. So there will be a small parasitic draw for balancing both batteries during that minute. This compact device has 3 connection points, main battery, secondary battery, and pre-wired ground. I highly recommend using a fused 4 gauge or higher cable from the main battery with the fuse or breaker fuse closer to the main battery, and a fused same gauge or lower wire out to your accessories from your secondary battery. Following the instructions I realized it wasn’t charging my secondary battery and wondered why. I later found that my main battery was faulting and after charging it for 8 hours didn’t hold a charge past 64%. With that said, it will only charge your secondary battery IF your main battery is charged past 13.4V. Once I got my main battery sorted (new one), everything was working as it should be. FYI, if either your main or secondary battery loses connection, the isolator will shut off by default. I tried to run the isolator in override mode to swap out the main battery without losing power, but found out that it simply shuts itself off. It’s a good thing. I also found out that this thing has a built in voltage spike regulator, similar to a power conditioner. But I wouldn’t consider it to be a conditioner either. Before this, I had an 80A Stinger battery isolator/relay between the main and secondary battery. I also had a 150A fuse breaker between the secondary to my rear fuse box for my accessories that kept tripping only during vehicle startup without any accessories ON. Battery to battery was fine over 80A relay, but the surge of power introduced by the alternator kept tripping my 150A breaker. After installing this, I had my 250W light bar ON running out of the secondary battery without tripping the breaker during startup. So in short, it can detect power spikes and send the correct signals. I highly recommend this if you’re into the whole secondary battery and trying to stay within budget. What’s $53 compared to potentially burning your entire electrical system (undercharging or overcharging) or getting stuck in a remote place without jumper cables. Hopefully this helps you think about what this thing is actually doing and what you’re protecting. I have a truck with a V8 5.0L engine and a stock 150A alternator, and the 125A/150A works for me. V6 and smaller motors with smaller applications can easily use 75A/100A system.

### ⭐⭐⭐⭐⭐ Great battery isolator
*by A***S on December 19, 2018*

Extremely easy install. Works as advertised. Very happy with this purchase, so far. UPDATE: I've adjusted the 5-star rating to a 3-star rating. Well, the honeymoon is over. LOL. The unit has been installed for a week and it's already acting fritzy. It was really great while it worked, but now long after I have shut the engine off, the blue light continues to burn. I tried pushing the reset button. It didn't work. I had to disconnect the entire unit to get the blue light to go off. When I reconnect it, the red light burns solid, as it should. I turn on the engine, the blue light clicks on. I shut the engine off...the blue light stays on. I've come back hours later to find it still burning. The only way to get it to turn off is to disconnect it. It's seems to be a defective unit. I'll probably be sending it back, unless there is some insight that WirthCo can share with me. The aux battery IS an agm battery, so that might have something to do with it. If this is normal behavior for the isolator when connected to an agm, my apologies. I will correct my rating back to 5-stars. UPDATE FOR THE UPDATE: The blue light will stay on when the AGM battery is completely full, which mine often is, since I wired it to a solar panel,too. When the AGM is slightly depleted, the blue light shuts off about a minute after I shut the ignition off. This is apparently very normal.

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*Product available on Desertcart Vanuatu*
*Store origin: VU*
*Last updated: 2026-02-01*