{"product_id":"renogy-12v-20a-dc-dc-battery-charger","title":"Renogy 12V 20A DC-DC Battery Charger","description":"\u003ch2\u003eShort Product Summary\u003c\/h2\u003e\u003cp\u003eThe Renogy 12V 20A DC-DC Battery Charger (RBC20D1U) charges your caravan, trailer or camper house battery from the tow vehicle's alternator while you drive. It takes the messy, uncontrolled voltage an alternator actually produces and turns it into a proper multi-stage charge at up to 20 A, with selectable profiles for lithium (LiFePO4), AGM, gel and flooded batteries. It works with traditional alternators and with the smart, variable-voltage alternators fitted to most modern bakkies and SUVs.\u003c\/p\u003e\u003ch2\u003eWhy This Product\u003c\/h2\u003e\u003cp\u003eA lithium house battery cannot be charged safely or fully straight off an alternator. Wire it directly and one of two things happens: the alternator sees a battery that will swallow every amp it can produce and cooks itself, or the alternator's regulation never lets the battery past roughly 80% and you arrive at camp with a bank that was never actually filled. A smart alternator makes it worse again, because it drops output voltage to almost nothing once the starter battery is topped up.\u003c\/p\u003e\u003cp\u003eA DC-DC charger sits between the two batteries and fixes all of that. It draws a fixed, limited current the alternator can live with, boosts the voltage to whatever your house battery actually needs, and runs a real bulk, boost and float cycle. On a South African trip that matters more than it does elsewhere: a run from Cape Town to the Cederberg, a long gravel transit through the Karoo, or three days of moving between camps is often the only charging opportunity you get, and this is what turns those driving hours into a genuinely full battery.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e20 A regulated charge current\u003c\/strong\u003e – puts a meaningful charge into your house bank on a two- or three-hour drive without loading the alternator beyond what it can handle.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSelectable battery profiles (LI, GEL, FLD, AGM, USER)\u003c\/strong\u003e – set it once for your battery chemistry and it charges to the right voltages every time; USER mode lets you dial in a custom profile.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSmart and traditional alternator support\u003c\/strong\u003e – traditional alternators need no ignition wire; smart Euro 6 alternators are handled by connecting the IGN signal input.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAlternator running detection\u003c\/strong\u003e – charging only happens when the engine is actually turning the alternator, so it never quietly flattens your starter battery overnight.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e94% charging efficiency\u003c\/strong\u003e – very little of the alternator's output is lost as heat between the two batteries.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLow idle draw under 15 mA\u003c\/strong\u003e – it can stay permanently wired in without measurably draining the vehicle when parked.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFull protection set\u003c\/strong\u003e – reverse polarity, over-voltage, over-discharge, over-current and over-temperature protection built in.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRS485 port for the optional BT-2 module\u003c\/strong\u003e – add Bluetooth and monitor or adjust the charger from the Renogy DC Home app on your phone.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompact sealed-look housing with cooling fins\u003c\/strong\u003e – 236.5 x 131.5 x 58 mm and 1.5 kg, small enough to mount in a nose cone, under a seat or in a battery locker.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eIdeal For\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eOff-road caravans and camping trailers running a lithium house battery that has to be charged on the move.\u003c\/li\u003e\n\u003cli\u003eBakkie canopy and 4x4 dual-battery builds where the second battery lives behind the cab or in the load bin.\u003c\/li\u003e\n\u003cli\u003eOwners of newer vehicles with smart alternators, where a plain isolator or split-charge relay simply will not charge properly.\u003c\/li\u003e\n\u003cli\u003eMulti-day Karoo, Kalahari and West Coast trips where driving time is the main charging opportunity.\u003c\/li\u003e\n\u003cli\u003eAnyone upgrading an older AGM setup to lithium and needing the charging side brought up to standard at the same time.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eLocal Support from 4Matt Campers\u003c\/h2\u003e\u003cp\u003e4Matt Campers is a Renogy dealer in Cape Town, serving customers throughout the Western Cape and delivering across South Africa. We work on off-road caravans and campers every day, so we can talk you through cable sizing, fusing, mounting position and whether a 20 A or a larger unit is the right call for your battery bank and your typical driving hours. Call or message us before you order if you are unsure what your vehicle's alternator setup requires.\u003c\/p\u003e\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eModel\u003c\/strong\u003e – Renogy RBC20D1U\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSKU\u003c\/strong\u003e – RBC20D1U-G1-SA\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSystem voltage\u003c\/strong\u003e – 12 V to 12 V\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAlternator input voltage\u003c\/strong\u003e – traditional alternator 13.2–16.0 V DC; smart (Euro 6) alternator 12–16.0 V DC\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaximum output current\u003c\/strong\u003e – 20 A (selectable 20 A or 10 A)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOutput power\u003c\/strong\u003e – 292 W\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSupported battery types\u003c\/strong\u003e – AGM, gel, flooded, lithium iron phosphate (LiFePO4) and user-defined\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCharging efficiency\u003c\/strong\u003e – 94%\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIdle power consumption\u003c\/strong\u003e – under 15 mA\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInput fuse rating\u003c\/strong\u003e – 40 A\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOutput fuse rating\u003c\/strong\u003e – 30 A\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTerminal range\u003c\/strong\u003e – 10 AWG to 8 AWG\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGrounding\u003c\/strong\u003e – common negative\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCommunication\u003c\/strong\u003e – RS485\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOperating temperature\u003c\/strong\u003e – -25°C to 60°C\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStorage temperature\u003c\/strong\u003e – -40°C to 85°C\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHumidity\u003c\/strong\u003e – 0–95%, non-condensing\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaximum operating altitude\u003c\/strong\u003e – 3000 m\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDimensions\u003c\/strong\u003e – 236.5 x 131.5 x 58 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e – 1.5 kg\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProtection\u003c\/strong\u003e – reverse polarity, over-voltage, over-discharge, over-current, over-temperature\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCertification\u003c\/strong\u003e – CE \/ RoHS \/ FCC\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eWhat's Included\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e1 x Renogy 12V 20A DC-DC Battery Charger (RBC20D1U)\u003c\/li\u003e\n\u003cli\u003eProduct documentation\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eBattery cable, ring terminals, fuses and fuse holders are not supplied and are sized to your specific installation.\u003c\/p\u003e\u003ch2\u003eOptional Fitment \u0026amp; Upgrade Notes\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eIf your vehicle has a smart or variable-voltage alternator, the IGN signal input must be wired to a switched ignition source. Without it the charger will not know when the engine is running. Traditional alternators do not need this connection.\u003c\/li\u003e\n\u003cli\u003eUse 10 AWG or 8 AWG cable on both the input and output sides, keep runs as short as practical, and fuse both ends close to the batteries: 40 A on the input, 30 A on the output.\u003c\/li\u003e\n\u003cli\u003eAdd the Renogy BT-2 Bluetooth module to the RS485 port if you want live charge data and settings on your phone through the DC Home app.\u003c\/li\u003e\n\u003cli\u003eMount it in a dry, ventilated spot. It sheds heat through its fins, so leave clear air around it and avoid burying it under bedding or gear.\u003c\/li\u003e\n\u003cli\u003eIf your house bank is 200 Ah of lithium or larger, or you tend to drive short distances between camps, step up to a 40 A or 50 A unit so the driving time you do get is worth more.\u003c\/li\u003e\n\u003cli\u003eFitment at our Cape Town workshop can be arranged – ask us when you order.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eComplete Your Setup\u003c\/h2\u003e\u003cp\u003ePair this charger with a proper house bank and a solar side that matches it. Browse our \u003ca href=\"\/collections\/lithium-batteries\"\u003elithium batteries\u003c\/a\u003e, \u003ca href=\"\/collections\/solar-charge-controllers\"\u003esolar charge controllers\u003c\/a\u003e, \u003ca href=\"\/collections\/solar-panels\"\u003esolar panels\u003c\/a\u003e and \u003ca href=\"\/collections\/electrical-accessories\"\u003e12V electrical accessories\u003c\/a\u003e, or see the full \u003ca href=\"\/collections\/renogy\"\u003eRenogy range\u003c\/a\u003e we carry.\u003c\/p\u003e\u003ch2\u003eFAQ\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eDo I really need a DC-DC charger for a lithium battery?\u003c\/strong\u003e\u003cbr\u003eYes. A LiFePO4 battery wired straight to the alternator either overloads the alternator or never reaches a full state of charge, and on a smart alternator it will barely charge at all. A DC-DC charger is the correct and safe way to charge lithium while driving.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill this work with my bakkie's smart alternator?\u003c\/strong\u003e\u003cbr\u003eIt will, provided you connect the IGN signal input to a switched ignition source. That connection tells the charger the engine is running. With an older traditional alternator the IGN wire is not required.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use this with an AGM battery instead of lithium?\u003c\/strong\u003e\u003cbr\u003eYes. Select the AGM, gel or flooded profile and the charger uses the correct voltages for that chemistry. It is also the right tool if you plan to move to lithium later.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much charge will 20 A actually give me?\u003c\/strong\u003e\u003cbr\u003eRoughly 20 Ah for every hour of driving, so a three-hour transit puts back about 60 Ah. If your bank is 200 Ah or more and you only drive short hops, a 40 A or 50 A unit is a better fit.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan it charge from solar as well?\u003c\/strong\u003e\u003cbr\u003eNo. This model has an alternator input only. If you want one unit that handles both the alternator and a solar array, look at the Renogy DC-DC charger with built-in MPPT instead.\u003c\/p\u003e","brand":"Renogy","offers":[{"title":"Default Title","offer_id":48299622891705,"sku":"RBC20D1U-G1-SA","price":2695.0,"currency_code":"ZAR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0764\/4587\/6409\/files\/12V_20A_DC_to_DC_Battery_Charger-1__47884.1736234950.1280.1280.jpg?v=1784793545","url":"https:\/\/www.4mattcampers.co.za\/products\/renogy-12v-20a-dc-dc-battery-charger","provider":"4Matt Campers","version":"1.0","type":"link"}