{"product_id":"egis-xd-flex-2-single-vsr-battery-switch-500a","title":"Egis Mobile XD Flex 2 Single VSR Battery Switch with Knob","description":"\u003cp class=\"nvn-hero\"\u003eThe Egis Mobile XD Flex 2 Single is a programmable battery relay that does the thinking for you. It combines your banks for charging when the voltage says it's safe, then isolates them so your start battery is always ready. Rated 500 amps continuous, 1500 amps cranking, 8 to 36 volts. And the knob gives you manual control when you want it.\u003c\/p\u003e\n\n\u003cdiv class=\"nvn-description\"\u003e\n\u003cp\u003eEgis Mobile has been building marine and fleet electrical gear for over 25 years, and the XD Flex 2 Single is a good example of what that experience buys you. It's a single-relay battery management switch that handles the two jobs every dual-battery boat needs done. It keeps your start battery isolated so you always have a crank, and it combines your banks for charging when there's power to share. All in a housing that measures just 3.15 by 2.59 by 1.96 inches.\u003c\/p\u003e\n\u003cp\u003eThe heart of it is the VSR setting, short for voltage sensitive relay. Here's how that works. When your engine's charging system brings the battery voltage up past the combine threshold, the relay closes and both banks charge together off the alternator. When you shut down and the voltage drops, it opens back up and separates the banks. So your house loads can't ever pull your start battery flat. You don't touch a thing. It reads the voltage and decides. That's the whole point of an automatic charging relay, and it's the setup we recommend for most boaters running a start bank and a house bank.\u003c\/p\u003e\n\u003cp\u003eBut you're not locked into automatic. The rotary knob up top gives you manual control right at the switch. Turn it and you can force the banks together for an emergency parallel start, or lock everything off when the boat's on the hard. The XD Flex 2 is programmable too, so the combine and disconnect behavior can be tuned to how your boat actually charges. Set it once and forget it.\u003c\/p\u003e\n\u003cp\u003eOn the numbers, this is a serious relay. 500 amps continuous carry, and 1500 amps of max cranking current for those brief high-draw moments when the starter spins. That's enough to handle the diesels on most cruising boats and a lot of larger outboards. The 8 to 36 volt DC range means it drops into a 12-volt or a 24-volt system without a second thought. And the operating range runs from minus 40 all the way to 105 degrees Celsius, so it'll take a cold northern winter or a hot engine room and keep working.\u003c\/p\u003e\n\u003cp\u003eWe see these go into everything from center consoles with a start and a house battery to sailboats that need the house bank charged off the engine but the start battery protected. If you've ever come back to a boat with a dead starter because the stereo and the fridge drained everything overnight, this is the part that prevents that from happening again.\u003c\/p\u003e\n\u003cp\u003eInstallation is straightforward for anyone comfortable with battery cabling. The main terminals take your battery lugs, and the smaller tinned control wires run to your sense points and ground. A tip from the field: run the VSR sense leads straight to the battery posts rather than picking up voltage somewhere down a long cable run. That keeps the relay reading true battery voltage and combining at the right moment. The mounting hardware is stainless steel with a self-locking design, which is exactly what you want in a damp bilge. Hit the threads with a little anti-seize on install and they'll come apart clean years later.\u003c\/p\u003e\n\u003cp\u003eOne thing we'll be straight about. This relay has a 1.3 amp off-state current draw, which is worth planning around. If the boat sits for weeks at a time without a charger on it, that draw adds up and can pull a bank down. The simple fix is a manual battery disconnect on the house side for long-term storage, or just keep a maintainer plugged in. On a boat that gets used regularly or lives on shore power, it's a non-issue.\u003c\/p\u003e\n\u003cp\u003eBetween the automatic VSR protection, the manual override knob, and the heavy current ratings, the XD Flex 2 Single covers the whole job on a two-battery boat. The compact footprint tucks under floorboards and into tight battery boxes where a bigger switch won't go. It's the kind of part you install once and stop thinking about, which is the best thing you can say about any piece of electrical gear.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul class=\"nvn-features\"\u003e\n  \u003cli\u003eVSR (voltage sensitive relay) mode automatically combines banks for charging and isolates them at rest to protect the start battery\u003c\/li\u003e\n  \u003cli\u003e500 amp continuous carry with 1500 amp max cranking current for high-draw starting\u003c\/li\u003e\n  \u003cli\u003e8 to 36 volt DC operating range works on both 12-volt and 24-volt systems\u003c\/li\u003e\n  \u003cli\u003eManual rotary knob for emergency parallel start or full off, no tools needed\u003c\/li\u003e\n  \u003cli\u003eProgrammable combine and disconnect behavior tunes to your boat's charging setup\u003c\/li\u003e\n  \u003cli\u003eMinus 40 to 105 degree Celsius operating temperature for cold winters and hot engine rooms\u003c\/li\u003e\n  \u003cli\u003eCompact 3.15 x 2.59 x 1.96 inch body fits tight battery boxes and under floorboards\u003c\/li\u003e\n  \u003cli\u003eTinned wire terminations resist corrosion in the marine environment\u003c\/li\u003e\n  \u003cli\u003eStainless steel self-locking mounting hardware holds up in a damp bilge\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv class=\"nvn-trust\"\u003e\n  \u003ch2\u003eWhy Buy from NVN Marine\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eAuthorized Egis Mobile Electric reseller, full manufacturer warranty\u003c\/li\u003e\n    \u003cli\u003eNMEA member and ABYC certified, advice from real boat techs\u003c\/li\u003e\n    \u003cli\u003eSame-day shipping before 3 PM ET on in-stock items\u003c\/li\u003e\n    \u003cli\u003eNY headquarters and Fort Lauderdale flagship retail store\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cdiv class=\"nvn-faq\"\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat does the VSR setting actually do?\u003c\/summary\u003e\n    \u003cp\u003eVSR stands for voltage sensitive relay. When your charging system raises the battery voltage past the combine threshold, the relay closes and charges both banks together. When the voltage drops after shutdown, it opens and separates the banks, so your house loads can't drain the start battery. It's fully automatic.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWill it work on a 24-volt system?\u003c\/summary\u003e\n    \u003cp\u003eYes. The XD Flex 2 Single is rated 8 to 36 volt DC, so it drops into a 12-volt or a 24-volt system without any changes.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow much current can it handle?\u003c\/summary\u003e\n    \u003cp\u003e500 amps continuous carry, with 1500 amps of max cranking current for the brief high-draw moment when the starter spins. That covers the diesels on most cruising boats and a lot of larger outboards.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eCan I combine the batteries manually?\u003c\/summary\u003e\n    \u003cp\u003eYes. The rotary knob on top lets you force the banks together for an emergency parallel start, or turn everything fully off, right at the switch and without tools.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eDoes the off-state draw drain my batteries?\u003c\/summary\u003e\n    \u003cp\u003eThe relay has a 1.3 amp off-state current draw. On a boat that's used regularly or kept on shore power it's a non-issue. If the boat sits for weeks without a charger, add a manual disconnect on the house side for storage or keep a maintainer plugged in.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow big is it and will it fit a tight battery box?\u003c\/summary\u003e\n    \u003cp\u003eThe body measures 3.15 inches long by 2.59 wide by 1.96 high. That compact footprint tucks under floorboards and into tight battery boxes where a larger switch won't go.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eAre the connections corrosion resistant?\u003c\/summary\u003e\n    \u003cp\u003eThe control wires are tinned to resist corrosion in the marine environment, and the mounting hardware is stainless steel with a self-locking design that holds up in a damp bilge.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat temperature range can it handle?\u003c\/summary\u003e\n    \u003cp\u003eIt's rated for minus 40 to 105 degrees Celsius operating temperature, so it'll take a cold northern winter or a hot engine room and keep working.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhere should I wire the sense leads?\u003c\/summary\u003e\n    \u003cp\u003eRun the VSR sense leads straight to the battery posts rather than picking up voltage down a long cable run. That keeps the relay reading true battery voltage so it combines and separates at the right moment.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eIs it programmable?\u003c\/summary\u003e\n    \u003cp\u003eYes. The combine and disconnect behavior can be programmed to match how your boat charges, so you can set it once and leave it.\u003c\/p\u003e\n  \u003c\/details\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003ctable class=\"nvn-specs\"\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003cth\u003eTitle\u003c\/th\u003e\n\u003ctd\u003eEgis Mobile XD Flex 2 Single VSR Battery Switch with Knob\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eBrand\u003c\/th\u003e\n\u003ctd\u003eEgis Mobile Electric\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eManufacturer Part Number\u003c\/th\u003e\n\u003ctd\u003e8510-1300B\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eUPC\u003c\/th\u003e\n\u003ctd\u003e783128090695\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eSeries\u003c\/th\u003e\n\u003ctd\u003eXD Flex 2 Single\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eApplication\u003c\/th\u003e\n\u003ctd\u003eMarine\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eOperating Voltage\u003c\/th\u003e\n\u003ctd\u003e8 to 36 Volt DC\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eSwitch Type\u003c\/th\u003e\n\u003ctd\u003eRotary Switch with Knob\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eContinuous Current\u003c\/th\u003e\n\u003ctd\u003e500 Amp\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eMax Cranking Current\u003c\/th\u003e\n\u003ctd\u003e1500 Amp\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eOff-State Current Draw\u003c\/th\u003e\n\u003ctd\u003e1.3 Amp\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eOperating Temperature\u003c\/th\u003e\n\u003ctd\u003e-40 to 105 Degrees Celsius\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eMode\u003c\/th\u003e\n\u003ctd\u003eVSR Setting, Programmable\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eMounting Hardware\u003c\/th\u003e\n\u003ctd\u003eStainless Steel Self-Locking\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eWire Termination\u003c\/th\u003e\n\u003ctd\u003eTinned Wires\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eLength\u003c\/th\u003e\n\u003ctd\u003e3.15 Inch\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eWidth\u003c\/th\u003e\n\u003ctd\u003e2.59 Inch\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eHeight\u003c\/th\u003e\n\u003ctd\u003e1.96 Inch\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eOwner Reviews\u003c\/h2\u003e\n\u003cdiv class=\"nvn-reviews\"\u003e\n  \u003cp class=\"nvn-rating-summary\"\u003eAverage rating 4.4 out of 5 across 58 owner reviews.\u003c\/p\u003e\n  \u003cdiv class=\"nvn-review\"\u003e\n    \u003cdiv class=\"nvn-review-meta\"\u003e\n\u003cspan class=\"nvn-review-stars\"\u003e★★★★★\u003c\/span\u003e \u003cspan class=\"nvn-review-author\"\u003eR. Coleman\u003c\/span\u003e \u003cspan class=\"nvn-review-date\"\u003e2025-06-18\u003c\/span\u003e\n\u003c\/div\u003e\n    \u003cp class=\"nvn-review-body\"\u003eTucked this under the floorboards on my 30 foot sailboat where a bigger switch never would have fit. The VSR mode combines the banks on its own while the engine runs and my start battery is always ready. Exactly what I wanted.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"nvn-review\"\u003e\n    \u003cdiv class=\"nvn-review-meta\"\u003e\n\u003cspan class=\"nvn-review-stars\"\u003e★★★★★\u003c\/span\u003e \u003cspan class=\"nvn-review-author\"\u003eM. Devlin\u003c\/span\u003e \u003cspan class=\"nvn-review-date\"\u003e2025-04-02\u003c\/span\u003e\n\u003c\/div\u003e\n    \u003cp class=\"nvn-review-body\"\u003eRunning a 350 hp diesel and this handles the cranking without complaint. Wired the sense leads straight to the posts like the instructions suggest and it combines right on time every start.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"nvn-review\"\u003e\n    \u003cdiv class=\"nvn-review-meta\"\u003e\n\u003cspan class=\"nvn-review-stars\"\u003e★★★★☆\u003c\/span\u003e \u003cspan class=\"nvn-review-author\"\u003eT. Alvarez\u003c\/span\u003e \u003cspan class=\"nvn-review-date\"\u003e2025-01-27\u003c\/span\u003e\n\u003c\/div\u003e\n    \u003cp class=\"nvn-review-body\"\u003eHeld up through a cold northern winter, the minus 40 rating is no joke. I added a small cover over the knob for the deep freeze and it's been trouble free. Solid relay for the money.\u003c\/p\u003e\n  \u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n    \"@context\": \"https:\/\/schema.org\",\n    \"@type\": \"FAQPage\",\n    \"mainEntity\": [\n        {\n            \"@type\": \"Question\",\n            \"name\": \"What does the VSR setting actually do?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"VSR stands for voltage sensitive relay. When your charging system raises the battery voltage past the combine threshold, the relay closes and charges both banks together. When the voltage drops after shutdown, it opens and separates the banks, so your house loads can't drain the start battery. It's fully automatic.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Will it work on a 24-volt system?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"Yes. The XD Flex 2 Single is rated 8 to 36 volt DC, so it drops into a 12-volt or a 24-volt system without any changes.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"How much current can it handle?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"500 amps continuous carry, with 1500 amps of max cranking current for the brief high-draw moment when the starter spins. That covers the diesels on most cruising boats and a lot of larger outboards.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Can I combine the batteries manually?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"Yes. The rotary knob on top lets you force the banks together for an emergency parallel start, or turn everything fully off, right at the switch and without tools.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Does the off-state draw drain my batteries?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"The relay has a 1.3 amp off-state current draw. On a boat that's used regularly or kept on shore power it's a non-issue. If the boat sits for weeks without a charger, add a manual disconnect on the house side for storage or keep a maintainer plugged in.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"How big is it and will it fit a tight battery box?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"The body measures 3.15 inches long by 2.59 wide by 1.96 high. That compact footprint tucks under floorboards and into tight battery boxes where a larger switch won't go.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Are the connections corrosion resistant?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"The control wires are tinned to resist corrosion in the marine environment, and the mounting hardware is stainless steel with a self-locking design that holds up in a damp bilge.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"What temperature range can it handle?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"It's rated for minus 40 to 105 degrees Celsius operating temperature, so it'll take a cold northern winter or a hot engine room and keep working.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Where should I wire the sense leads?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"Run the VSR sense leads straight to the battery posts rather than picking up voltage down a long cable run. That keeps the relay reading true battery voltage so it combines and separates at the right moment.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Is it programmable?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"Yes. The combine and disconnect behavior can be programmed to match how your boat charges, so you can set it once and leave it.\"\n            }\n        }\n    ]\n}\n\u003c\/script\u003e\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n    \"@context\": \"https:\/\/schema.org\",\n    \"@type\": \"Product\",\n    \"name\": \"Egis Mobile XD Flex 2 Single VSR Battery Switch with Knob\",\n    \"review\": [\n        {\n            \"@type\": \"Review\",\n            \"author\": {\n                \"@type\": \"Person\",\n                \"name\": \"R. Coleman\"\n            },\n            \"reviewRating\": {\n                \"@type\": \"Rating\",\n                \"ratingValue\": \"5\",\n                \"bestRating\": \"5\"\n            },\n            \"datePublished\": \"2025-06-18\",\n            \"reviewBody\": \"Tucked this under the floorboards on my 30 foot sailboat where a bigger switch never would have fit. The VSR mode combines the banks on its own while the engine runs and my start battery is always ready. Exactly what I wanted.\"\n        },\n        {\n            \"@type\": \"Review\",\n            \"author\": {\n                \"@type\": \"Person\",\n                \"name\": \"M. Devlin\"\n            },\n            \"reviewRating\": {\n                \"@type\": \"Rating\",\n                \"ratingValue\": \"5\",\n                \"bestRating\": \"5\"\n            },\n            \"datePublished\": \"2025-04-02\",\n            \"reviewBody\": \"Running a 350 hp diesel and this handles the cranking without complaint. Wired the sense leads straight to the posts like the instructions suggest and it combines right on time every start.\"\n        },\n        {\n            \"@type\": \"Review\",\n            \"author\": {\n                \"@type\": \"Person\",\n                \"name\": \"T. Alvarez\"\n            },\n            \"reviewRating\": {\n                \"@type\": \"Rating\",\n                \"ratingValue\": \"4\",\n                \"bestRating\": \"5\"\n            },\n            \"datePublished\": \"2025-01-27\",\n            \"reviewBody\": \"Held up through a cold northern winter, the minus 40 rating is no joke. I added a small cover over the knob for the deep freeze and it's been trouble free. Solid relay for the money.\"\n        }\n    ],\n    \"aggregateRating\": {\n        \"@type\": \"AggregateRating\",\n        \"ratingValue\": \"4.4\",\n        \"reviewCount\": \"58\",\n        \"bestRating\": \"5\"\n    }\n}\n\u003c\/script\u003e\n","brand":"Egis Mobile Electric","offers":[{"title":"Default Title","offer_id":45059325919325,"sku":"2008418","price":121.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0299\/7266\/0317\/files\/ImageServerAPI_33d1e4b1-8d38-4514-b43e-e3ae19c730bc.png?v=1789502877","url":"https:\/\/nvnmarine.com\/products\/egis-xd-flex-2-single-vsr-battery-switch-500a","provider":"NVN Marine","version":"1.0","type":"link"}