KeyLine Chargers 300A dual battery isolator front view, compact under-hood.
KeyLine Chargers Pro HD kit contents, ready-to-install for quick setup.
KeyLine Chargers VSR wiring cuts in at 13.3V to protect the start battery.
KeyLine Chargers IP65-certified unit for dusty, wet conditions.
KeyLine Chargers compact design fits under the hood.
KeyLine Chargers works with lithium and LiFePO4.
KeyLine Chargers complete kit with all components included.
KeyLine Chargers 3-year warranty and support.
KeyLine Chargers 300A dual battery isolator front view, compact under-hood.
KeyLine Chargers Pro HD kit contents, ready-to-install for quick setup.
KeyLine Chargers VSR wiring cuts in at 13.3V to protect the start battery.
KeyLine Chargers IP65-certified unit for dusty, wet conditions.
KeyLine Chargers compact design fits under the hood.
KeyLine Chargers works with lithium and LiFePO4.
KeyLine Chargers complete kit with all components included.
KeyLine Chargers 3-year warranty and support.

KeyLine Chargers 300A Dual Battery Isolator Kit – 12V VSR, Lithium Compatible

OverviewMeet the KeyLine Chargers Heavy Duty 300A Dual Battery Isolator Kit, a rugged solution for demanding 12V...
Vendor: KeyLine Chargers
Availability: In stock
£232.49
£232.49
Please hurry! Only 5 left in stock
Subtotal: £232.49
10 customers are viewing this product

Free UK Delivery on All Orders

No Minimum Spend Fast & Reliable Delivery Ships Across the UK

Free Returns

30-Day Free Returns
KeyLine Chargers 300A dual battery isolator front view, compact under-hood.

KeyLine Chargers 300A Dual Battery Isolator Kit – 12V VSR, Lithium Compatible

£232.49
KeyLine Chargers 300A dual battery isolator front view, compact under-hood.
KeyLine Chargers Pro HD kit contents, ready-to-install for quick setup.
KeyLine Chargers VSR wiring cuts in at 13.3V to protect the start battery.
KeyLine Chargers IP65-certified unit for dusty, wet conditions.
KeyLine Chargers compact design fits under the hood.
KeyLine Chargers works with lithium and LiFePO4.
KeyLine Chargers complete kit with all components included.
KeyLine Chargers 3-year warranty and support.

KeyLine Chargers 300A Dual Battery Isolator Kit – 12V VSR, Lithium Compatible

£232.49
Description
Description
x

Overview

Meet the KeyLine Chargers Heavy Duty 300A Dual Battery Isolator Kit, a rugged solution for demanding 12V systems. This Voltage Sensitive Relay (VSR) sits between your start battery and auxiliary bank, engaging at a controlled threshold to balance power delivery while keeping your engine-ready battery primed. It’s designed to work with all battery types, including lithium and LiFePO4, making it a versatile upgrade for off‑grid adventures, work sites, and long days on the road.

Key specs at a glance

  • Continuous current up to 300A with a 1000A peak for short bursts
  • Voltage Sensitive Relay behavior: cuts in at 13.3V, cuts out at 12.8V
  • IP65-rated protection for dusty, wet, and rugged environments
  • Ultra-compact footprint designed to fit under the hood or in tight spaces
  • Professional-grade hardware backed by a 3-year warranty

What’s in the kit

  • 1x Smart Battery Isolator with mounting screws
  • 20 ft (6 m) of 1 AWG red cable
  • 2 ft (61 cm) 1 AWG black ground cable
  • 2x positive and 1x negative marine battery terminals
  • 3x 1 AWG copper crimp lugs
  • 2x red and 1x black heat shrink tubing
  • 1x insulated ring terminal
  • 6x 8” zip ties

Installation and use

The kit is built to simplify upgrading a dual battery setup. Its compact form makes it easy to mount under the hood or near your batteries, while the included components reduce shopping time. The device is designed for straightforward wiring and reliable performance in variable conditions.

Compatibility and practical use

Beyond standard lead-acid, this isolator supports lithium and LiFePO4 chemistries, enabling flexible power management for accessories, inverters, and auxiliary loads. Users may experience more consistent alternator charging behavior and better utilization of stored energy, depending on their configuration.

Warranty and support

KeyLine Chargers backs the 300A Dual Battery Isolator with a 3-year warranty and a customer‑focused returns policy. For questions or assistance with installation, support is available to help you get the most from your setup.

FAQ

Q: Is this isolator compatible with all 12V battery types, including LiFePO4?

A: Yes. It supports 12V systems and works with all battery types, including lithium and LiFePO4.

Q: What comes in the kit and is installation straightforward?

A: The kit includes the isolator, cables, terminals, heat shrink, and ties; designed for tool-friendly, straightforward setup.

Shipping & Return
Shipping & Return
x

Returns Policy

You may return most new, unopened items within 30 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.

Shipping

We can ship to virtually any address in the world. Note that there are restrictions on some products, and some products cannot be shipped to international destinations.

When you place an order, we will estimate shipping and delivery dates for you based on the availability of your items and the shipping options you choose. Depending on the shipping provider you choose, shipping date estimates may appear on the shipping quotes page.

Please also note that the shipping rates for many items we sell are weight-based. The weight of any such item can be found on its detail page. To reflect the policies of the shipping companies we use, all weights will be rounded up to the next full pound.

Complete Your Setup

Example product title
£232.49
£232.49
Example product title
£232.49
£232.49
Example product title
£232.49
£232.49
Example product title
£232.49
£232.49
Example product title
£232.49
£232.49
Example product title
£232.49
£232.49
Example product title
£232.49
£232.49
Example product title
£232.49
£232.49
Example product title
£232.49
£232.49
Example product title
£232.49
£232.49

Recently Viewed Products