Recoil SRL500 Review: 500 A Smart Battery Isolator With 13.2 V Connect Point
The Recoil SRL500 is a microprocessor-controlled smart battery isolator and high-current starter relay, rated for 500 A continuous at 12 V and 700 A surge. Recoil says it connects the two batteries once the main battery reaches 13.2 V and disconnects them below 12.7 V. Its Indian MRP is ₹15,000. Recoil's US page describes it for dual-battery vehicles with high-draw audio systems or auxiliary equipment. The relay is on our Recoil SRL500 product page.
Quick summary
The ratings are 500 A continuous at 12 V and 700 A surge. They are current ratings for the relay, not an amplifier-power figure.
Recoil's main-site page gives a 13.2 V connect point, a 12.7 V disconnect point, dual sensing and a waterproof manual override that joins the batteries for 60 seconds. The US page omits the 12.7 V point and the override.
This is the smart model. The simpler Recoil BRL500 lists none of those features and is ₹5,000 lower at MRP.
Recoil publishes no wiring diagram, fuse or cable advice, IP rating or standby draw, and we found no owner or reviewer write-ups.
Recoil SRL500 specifications
Specification | Recoil SRL500 |
|---|---|
Type | Microprocessor-controlled smart battery isolator and high-current starter relay |
Current | 500 A continuous at 12 V; 700 A surge |
Connects the batteries | When the main battery reaches 13.2 V |
Disconnects the batteries | When the system drops below 12.7 V (not on the US page) |
Sensing | Dual sensing |
Voltage drop to second battery | None, per Recoil |
Manual override | Waterproof switch; connects both batteries for 60 seconds (not on the US page) |
Weather protection | Waterproof performance claimed on the main-site page; no IP rating given |
Supplied | Two 1/0 AWG copper ring terminals; heat-shrink tubing |
Size and weight | 3.5 x 3 x 4.1 in (about 89 x 76 x 104 mm); 2 lb (0.9 kg) |
India MRP | ₹15,000 |
The figures come from our listing and from Recoil's SRL500 page on its main site and US store page, both promotional. Size and weight are on the main-site page only. Metric figures are our conversions of Recoil's inches and pounds.
How the SRL500 switches the batteries
Recoil's main-site page gives two switching points. The smart relay connects the two batteries once the main battery reaches 13.2 V and disconnects them once the system drops below 12.7 V, a gap of 0.5 V. A running charging system normally holds a car battery above 13.2 V, which points to the batteries joining while the alternator charges and parting after the engine stops. Recoil does not describe a driving cycle or say whether the points can be adjusted.
Recoil says dual sensing allows charging both ways if the auxiliary battery is charged by an external power source, and its US page says the relay monitors both battery banks independently. Recoil does not name the external sources, so confirm what is supported with Recoil or its distributor.
The manual override is a waterproof switch that connects the two batteries at the push of a button for 60 seconds. Recoil does not say when to use it, whether the switch is built in or supplied separately, or how it is wired. The title and a tag also call the SRL500 a high current starter relay, but neither Recoil page explains a starting use, so we describe it as an isolator, which is how the page text describes its job.
SRL500 or BRL500: which Recoil isolator is which
The Recoil BRL500 is the simpler 500 A isolator. Both list 500 A continuous and 700 A surge and say there is no voltage drop to the second battery. Beyond that the pages differ, and the BRL500 pages do not say how it switches.
Specification | Recoil SRL500 | Recoil BRL500 |
|---|---|---|
Type | Microprocessor-controlled smart isolator and starter relay | Battery isolator; switching method not stated |
Switching points | 13.2 V connect, 12.7 V disconnect | Not published |
Dual sensing | Yes | Not listed |
Manual override | Waterproof switch, 60 seconds | Not listed |
Size and weight | About 89 x 76 x 104 mm; 0.9 kg | About 100 x 75 x 97 mm; 0.8 kg |
India MRP | ₹15,000 | ₹10,000 |
Recoil's BRL500 US page says standard diode isolators typically lose 0.6 to 0.7 V, a loss it says the BRL500 does not have. The SRL500 pages make the no-voltage-drop claim without a figure. Both are maker claims.
What the 500 A and 700 A ratings mean
These are current ratings for the relay at 12 V, not watts of amplifier power, and Recoil does not say how long the 700 A surge may last. Your real load comes from the amplifiers and other equipment on the second battery, and the cables must suit it. Recoil's US page claims the relay handles this current without thermal throttling or voltage loss, which we have not tested.
What Recoil does not publish
Neither Recoil page gives a wiring diagram, installation steps, fuse or cable-gauge advice, standby current draw, an IP rating, a temperature range, LED indicators, stud size or the battery types it supports. The only installation details are the two 1/0 AWG ring terminals and the heat-shrink tubing in the box. One tag on the main-site page reads 200-AMP, which disagrees with the 500 A in its title and text. We use 500 A, which our listing and the US page also give.
Installation notes for Indian cars
A dual-battery install carries high current, so cable size and fusing matter, and Recoil publishes figures for neither. Take them from the manual and your loads, and keep the relay in a dry spot close to the batteries so the heavy cable runs stay short. Treat the waterproof claim as unrated because no IP figure is given, and check the battery types with Recoil or its distributor before pairing two different kinds. VA3 Car Studio in Ghaziabad offers professional installation, which suits a job like this.
What owners and reviewers say about the Recoil SRL500
We looked for owner and reviewer feedback in October 2026 and found nothing we could read for the SRL500. Recoil's main-site page shows Reviews (0) and its US page shows none. Our tools could not read Amazon, Walmart or Reddit, and forum and retailer search pages did not load, so feedback may exist that we could not see.
Who should buy it, and who shouldn't
Buy the SRL500 if you run, or plan, a second battery for a high-draw audio system and want an automatic isolator with published switching points, dual sensing and a manual override. Our guide to the need for an amplifier in car sound systems covers the load side.
Look elsewhere if you want the simpler, lower-MRP BRL500, need a wiring diagram, fuse advice or an IP rating before buying, or are fighting brief voltage dips rather than engine-off drain. Our post on the Recoil REC5D covers a capacitor, which supplies short bursts.
Price and where to buy
The Recoil SRL500 carries an India MRP of ₹15,000. We often sell below MRP, so check today's price on the Recoil SRL500 product page. Our listing describes it as a genuine Recoil product.
The bottom line
The SRL500 is the smart one of the two Recoil 500 A isolators we list, with 13.2 V and 12.7 V switching points, dual sensing and a manual override at ₹15,000 MRP. Its wiring details, weather rating and battery-type limits are not published, so ask the maker or distributor before you buy.
Recoil SRL500 FAQ
At what voltage does the Recoil SRL500 connect the batteries?
Recoil's main-site page says the smart relay connects the two batteries once the main battery reaches 13.2 V and disconnects them below 12.7 V. Its US page gives only the 13.2 V point.
What is the difference between the Recoil SRL500 and BRL500?
The SRL500 is a microprocessor-controlled smart isolator with listed switching points, dual sensing and a manual override, at ₹15,000 MRP. The BRL500 is the simpler isolator at ₹10,000 MRP, with none of those features listed.
Does the SRL500 have a manual override?
Yes. Recoil's main-site page lists a waterproof manual override switch that connects the two batteries for 60 seconds at the push of a button. It does not say when to use it or how it is wired.
Is the SRL500 waterproof?
Recoil's main-site page claims excellent waterproof performance in any weather conditions but gives no IP rating, so we cannot state one.
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