Affordable Dual Battery Setup Using DC-DC Charger-Easy DIY

we're going to show you how you can have a super reliable state-of-the-art secondary power supply for powering a fridge lights water pump you name it using one of these dc to dc chargers without spending a fortune on it we're going to show you all the parts required and exactly how we installed ours under the hood and we're going to get at it right now we provide links to all the parts we used in the video description there's five things you're going to need first a place and a way to mount the extra battery in our vehicle like most suvs the most practical spot is under the hood yes it gets a tad bit warm under here and there's a little moisture and dust but it's really all we have to work with we're using a battery tray that's specifically made for our application a 2007 toyota fj cruiser aftermarket suppliers will likely have one available for your make and model 2. these can get expensive though we spent 230 dollars on this now if you want to save some money and you have the skills to do it get yourself a universal battery tray like this and along with some bolts maybe some spacers some extra metal you have laying around to make some brackets to fit on your inner fender well you'll save a ton of money next you need a second battery our space limits us to the size of a group 48 now this is where you can spend a lot of money from a hundred dollar cheapie that won't perform well or last very long to almost a thousand dollars for a huge output lithium our choice is a moderately priced agm battery that stores a modest 72 amp hours and came in right around 295 dollars now a way to charge it when it drains down and to maintain that charge when we're driving the proven best way to do that is with a dc to dc charger and one of the most reliable trusted ones on the market is this one from ctek why a dc to dc charger why not just charge this battery the same way we do the starter battery with cables from the alternator basically two reasons different types of batteries have different duties to perform and their own special charging requirements the starter battery normally a flooded acid battery has only one chore to do and that's to crank over the engine during startup it's designed to send out a huge amount of amperage for a very short period of time the secondary or house battery is designed to put out a relatively low amount of amperage over a long period of time second most modern vehicles built after say 2008 have what's called a smart alternator basically they don't put out a high enough voltage to fully charge an agm battery and an agm battery has a special way it prefers the voltage to drop during the charging cycle so if you treat it nice and charge it the right way this battery will give you back peak performance and a long life we're going to show you exactly how to wire everything in very soon wires to connect it all together because our ctek dc to dc charger only draws 20 amps to operate we don't need thick very expensive cables connecting the two batteries according to our wire sizing chart with 20 amps of draw going through seven feet of wire we need at least 12 gauge wire we're going to go one size larger to 10 gauge protection keeping all this safe from short and unlikely but possible malfunction we prefer circuit breakers like this mostly because they double as on off switches we size two at 30 amps and one at 40 amps to save some money instead of these you could always use traditional inline fuses like these now we put it all together as you can see we have our battery in place and this is how and where we mounted our charger a piece of 3 8 inch thick hdpe plastic that we had laying around anything you have available will work even plywood stainless steel bolts holding down the charger and the circuit breakers here we have a 30 amp breaker for in between the charger and the battery and a 40 amp breaker for in between the battery and what we're powering out back the panel also serves as the battery hold down now to wire everything up beginning at the starter battery do yourself a huge favor and change your battery terminals over to a set like these they make adding connections much easier and safer they're made by sdhq we'll put a link in the video description for the best level of protection from any breaker or fuse it needs to be placed as close to the power source as possible in our case we placed ours right here on top of the factory fuse box leaving plenty of slack in the cable so we can open it and get to the fuses in there the first wire we put on is a real short one from the positive terminal on the starter battery to this post on our circuit breaker make sure these breakers are turned off or the fuses are pulled until you get everything in place we're running both positive and negative wires from the starter battery over to the ctek charger some experts say that's the best practice others say it's not necessary just use a body ground for the negative but this small gauge wire is relatively cheap so we're running both we did encase both together in an abrasive resistant cover at the charger the positive from our starter battery attaches here the negative wire goes right to the second battery's negative post coming out of the charger with the positive we first go through the 30 amp breaker then we come out of that breaker right to the positive post on our second battery next we need a short wire from this negative point on the charger to the battery's negative post another great benefit of this ctek charger is there's a built-in solar controller no need for a separate component we use a portable solar panel when we're in camp to keep our battery topped off even when the engine's not running until the sun goes down that is to wire it in we're using a popular type of plug that'll go to our solar panel and 10 gauge wire the positive goes here on the charger and the negative here the panel already has an inline fuse for protection so all we have to do now is simply plug it in when we need it now on to these small wires coming out of the charger right here this is a temperature sensor we're going to tape it right onto our battery next to the positive post here we have a red and a black wire how we hook up the red wire will tell the charger if we have an old style alternator or a new smart alternator for a smart alternator we have to tie this wire into the fuse box behind the dash we tied into a spot where there's power when the key is on the ignition position how the black wire's hooked up will tell the charger what type of battery it's charging leave it unhooked or dead ended for a normal battery like our starter battery tapped into a 12 volt power source for a lithium battery for an agm battery like this all we have to do is connect it to a ground if the service battery you're using is 100 amp hours or more or you want to greatly reduce the amount of time it takes the battery to come up to a full charge you're going to want to look into something like this this is ctek's smart pass the dc to dc charger pumps in 20 amps to charge the battery when you wire this in with the charger you get up to 140 amps going in to charge the battery now it's required that you use much larger gauge wire from the starter battery to power all this it's just a thought this is all hooked up now we need to get the power back to our lights and fridge first we need to determine what gauge wire and size breaker we need now we added up the amps that all our possible accessories are going to draw our fridge lights a possible diesel heater now the likelihood that all these things are going to be running at the same time is pretty slim but we have to prepare for that regardless ours came to a grand total of 30 amps the length of the wire going from the battery to the rear is about 15 feet looking back at our chart we determined we need an eight gauge wire to safely transfer that power back there but first you guessed it it has to go through yet another circuit breaker this we size to 40 amps again we could just run the ground through the body but we're going to run a negative cable back there too but that's for another video when we get it all done we'll place a link at the end of this video and in the video description and it will show us running the cables back there uh putting in a fuse panel of 12 volt outlets usb chargers and a volt gauge now we spent right around eleven hundred dollars for our system but by making your own battery tray using fuses instead of relays spending a little less money on a battery and you can trim that down to around 750 now i know that still sounds like a lot but that includes everything battery wires charger fuses everything everything if you like this video and you want to see more consider subscribing and look us up on facebook and instagram thanks for watching agm battery that stores a modest our choice is a moderate moderate really yeah basically two reasons what are the two reasons from shorts okay state-of-the-art secondary oh close almost right we're going to show you how you can have a super reliable we use a portable solar panel when we're and hit that bell icon for notifications

Channel: Wanderlost Overland

Views: 74,434

Rating: 4.9104991 out of 5

Keywords: dual battery kit, dual battery isolator, second battery kit, second battery, fridge battery setup, dc-dc charger, overland power, overland dual battery setup, overland dual battery system, dual battery system, auxiliary battery, auxiliary battery system, battery isolator, dual battery, dual battery kit installation, optima agm battery, dual battery system install, agm battery, 4Runner dual battery, 12v, 12 volt, cheap, overland, overlanding, refrigerator, do it yourself

Id: la1Em1WOisA

Length: 11min 21sec (681 seconds)

Published: Sun Mar 21 2021