House battery in the engine

[Theadyn]

Let me warn..  I am no mechanic.   :dodgy:    I need the wisdom of you good people.

Does anyone have their house battery under the hood of their engine?   I have a space that appears to be made for a battery, and was told that is where the extra battery would be had my motor been a diesel.  Since it is a gas engine, I see a perfectly unused space that is not being put to good use.

Is it possible, or does anyone do this themselves, to install a house battery there and set it up to charge off the alternator while the motor is running.   My needs will be small, and I will be driving...  a lot.

My needs may be for cell phone charging, laptop charging and/or dvd's in the evening, kindle charging, etc.  No fridge or heavy use electric needs, I'm trying to go for simple.  I had planned, for now, to charge those things while driving through the dash cigarette lighter.  But with this discovery of space, wondered if this would be a better solution. 

With my meager knowledge of motors and electricity, I wasn't able to search much, probably because I am limited and the 'HOW' to search for it, not asking the right questions.  My limited findings, thus far, are to mount a deep cycle marine battery and run a continuous duty 12v DC solenoid to charge from the alternator.  I think, haha.  Would of course have to have someone else set this up. 

Anyone done this or is doing this now?  Advice?

 

[kyonu]

Lots of older RV's had their battery in the engine, it was a well ventilated area for them. If you have the room, give it a shot, but be warned that batteries are heavy, and may affect the sway of the vehicle!

 

[nwprimo]

Search for a duel battery isolator

 

[karl]

Lots of light trucks have the auxiliary battery under the hood to power plows, hoists, campers. Some/most of them are wired through a solenoid or isolater at the factory.
Sprinter puts their aux batt under the hood...even though they install the start batt under the floor(Hmmm?)

The upside is shorter fat cables to the alternator and easy access, down side is longer thinner wires to your equipment. Fair trade, I think.

If your not using lots of power, and just need a couple charging outlets, I'd do it for sure.

Wouldn't worry much about affecting the vehicle handling if the factory engineered for a battery in that spot.

Someplace in the electrical threads is a good explanation of wiring up a continuous duty solenoid so that you don't draw from the house batt.

A mechanic or audio shop can do the install if you don't want to attempt it.
Personally, I prefer a $20. continuous duty solenoid to a more expensive isolater for my meager use.
http://www.amazon.com/CONTINUOUS-SO...solenoid&pebp=1422279128282&peasin=B00BGTL9GI

I would spend the extra for good quality power outlets though. Sorry, don't have a source..

 

[Reducto]

The only reason most of us have our cabin batteries in the cabin is because that's the only place we have room. If your battery fits under the hood, go for it! It's going to be safer that way.

 

[MikeRuth]

Hi there and good day. above advice is good, and I know you said have someone else set this up. I don't want to scare you but do not do this your self without qualified help assisting you. One wrong connection or simple mistake can cause serious damage. I think it's great if you want to learn and do these things but have help to oversee and teach you.
With that said you will need the following items.

The battery, in this case a Deep cycle/Marine is what they are called even though they are not true deep cycle. you will need to measure you open space to determine which battery you can place there. Example
Battery hold down if it is not already in place at that empty spot.

A suitable Fuse and holder to be used between the battery and the alternator connection. with a marine battery I'd say about 100 amp
A continuous duty Solenoid rated to 150 Amps with a spike of 300. Why so large? having a bit more at no additional cost will preserve life span.

A switch to turn this solenoid on and off. I use one with a protective cover and led light that lets me know I have it on.

(A Battery Isolator and or automatic isolator can be used but I'd suggest the manual switch and solenoid.)
Battery cables, one for ground and one to the alternator and appropriate Terminals. It's best to connect it directly to the alternator. Custom made cables IMHO are best or off the shelf if you can get lengths that work out.  

A second fuse Approximately a 30 amp and wire that will run back into the vehicle were you will have access/connections to this new power source. Possibly a fuse block for multiple items. 

Outlets appropriate for your needs.

I listed these as examples of whats involved here, by no means are these what I'm saying you need as each item needs to be selected based on your vehicle fit etc. More to help you understand whats involved. 

Mike R

 

[ccbreder]

Whatever battery that would fit in the extra battery tray will not in any way effect the handling of the van.

 

[flying kurbmaster]

I have my house battery under the hood, I installed a rack I found in a wreck and installed it, I have it connected to a marine switch and it is hooked up to the main battery. With the switch I can use the house battery alone and not discharge the starter battery, charge one or the other or both while driving. I don't have any fuses connected between these, I do have fuses to all the lights and other appliances.

 

[SternWake]

Having space in the engine compartment for an additional battery is a thing of beauty.  One advantage of having a battery elsewhere, is that batteries in the engine compartment have their lifespan curtailed to some degree by engine heat.

To make the alternator charging circuit most effective, one needs to use thick cabling between alternator and battery. I'd recommend no thinner than 6awg with 4awg and thicker being preferable. This includes the ground cables.  One adds fuses to protect the cabling used, not the alternator or the battery or any appliance attached to the wire cable.  Size fuses to cable gauge used.

Most people consider the laptop to not use much electricity.  This is false.  Laptops can be huge energy hogs.  My laptop, in one hour of internet use, uses more than 3 times what my compressor fridge uses in that same hour to keep the internals at 33.5f, and that is if the laptop battery is already fully charged.

One other possible issue about a house battery in the engine compartment is the wiring of an inverter.  Inverters should be wired to the battery over short thick cables, and then AC extension cords used to reach distant AC appliances.  One can move the inverter further away, but then longer lengths of thicker copper must be used.  If one installs inverter in engine compartment, then one has to deal with engine heat and rainwater.  The bigger the rating of the inverter, the more important it is that  short lengths of  thick cables are used.

You do not necessarily need an inverter with what you list as electrical devices.  I think inverters are evil, but a necessary evil.  I believe too many people see them as a solution to all household electrical needs but then have no idea how much energy the battery has to provide, and how much effort/time is required to fully recharge the battery.  Inverters are a great way to deplete a battery.


'Keeping it simple', and adding an auxiliary battery are kind of at opposite ends of the spectrum.  Electrical usage tends to increase so having a dedicated battery for 'engine off' devices is wise.

Now here is the obligatory lead acid battery rant.

Lead acid batteries want to live their whole life as close to fully charged as possible.  The deeper the battery is cycled and the longer it sits below full charge, the faster the battery will degrade and lose capacity.  Every 14 deep cycles or so, it is very important to get the battery back upto 100% full charge.  This is not easily accomplished as it requires many hours at voltages in the mid 14's.

If the battery is not returned to 100% after 15 or so deep cycles, then the battery capacity walks downward and will start walking downward faster, and the longer the battery goes without a full charge, the more permanent this capacity loss is.

The alternator, if thickly cabled, can recharge a battery to ~80% charged fairly quickly.  However getting that last 20% into the battery will take a minimum of 4 hours, no matter what charging source is used, no matter how big or shiny the alternator and no matter how fat the copper cabling.  Most everybody on the planet acts like alternators are magical near instant battery chargers, even those who should know better, but the facts are that lead acid batteries resist returning to full charge, and that time is needed at higher voltages before the battery can accept no more juice.

So thickly wiring the Aux battery with thick cables allows the alternator to quickly return the battery upto 80% charged, allowing shorter drives to be more effective at keeping the battery at a higher state of charge.  The 80% level is kind of the hinge point.  When batteries sit under 80% charged the sulfates on the plates are hardening, and become harder to redissolve into the electrolyte.  Keeping a battery 85% charged is orders of magnitude better than keeping it 75% charged.  But there is not too much difference between 75% and 65%.

Batteries are basically rented.  The length of the rental contract is dependent on how they are used and how they are recharged.  One can stress the details to recharge them as best as possible, or just resign themselves to battery replacement more frequently.  The battery depleter needs to find a comfortable medium.

 

[SternWake]

If one does install a house battery, then it is also wise to move all house loads to it. Ciggy plugs, stereo. Interior lights can be moved from engine battery to house battery, and this is not that difficult to do.

Also replacing incandescent lightbulbs with LED can save lots of battery power. It is easier to use less, than it is to create more. Incandescent bulbs waste a lot of battery for not much light. LED use 1/4 or less for the same amount of light.

 

[Theadyn]

A whole lot to think about, thank you guys!!!

Got all the maintenance work done today and they surprisingly didn't hit the pocket book too hard. (helps to know people that know people)

I actually am taking the van in on Friday for full window tinting at an audio place (the owner was at mine and my late hubby's wedding.. and his brother in law was best man and my late hubbies best friend in the world, and who is paying to have it done). Good to know people. I guess I could ask while it's there what they can recommend to hook this up professionally.

 

[flying kurbmaster]

I was thinking that if there is a spot for a battery under the hood it already may be hooked up all you have to do is find the cables that may be tucked or taped to or under something, it wouldn't surprise me with that kind of van that you already have a house battery set up, only missing the battery. just thinking outloud...

 

[HarmonicaBruce]

If all you're going to use your auxiliary battery for is to charge your cell phone, lap top, and dvd player, I don't think you need it.  Are you going to use an inverter to convert 12v dc to 110 ac, then use a wall charger to convert the 110 ac back to dc to charge your cell phone etc?  That wastes a lot of power.  Why not just get car chargers for your cell phone, laptop, and dvd player?  Or even get a small inverter, plug into the cigarette lighter while you drive, and plug in an ac charger.  The house battery you're talking about could be useful if you were boon docking for weeks at a time.  But you're going to be driving a lot, so you'll be able to charge while you drive.  If your laptop battery goes dead from using it all night, it would be cheaper and simpler to get a second laptop battery than to rig up a house battery. 

 

[SternWake]

+1 on the car chargers.  I forget the exact numbers but my car charger on my laptop consumes significantly less battery power than my 400 watt Pure sine wave inverter powering the provided power brick. 
Devices which use USB ports to charge:
http://www.amazon.com/Blue-Sea-Systems-Charger-Socket/dp/B0082CXEI8
or
http://www.amazon.com/s/ref=sr_pg_2...ywords=usb+car+charger&ie=UTF8&qid=1422341956.
Most Android phones and iphones require 1 amp at 5 volts, while tablets can require 2.1 amps.  Lots of the cheapo usb converters can only handle 0.5 amps so check first.
For your laptop, type in make and model number into search and add 'car charger'.  Mine was 22$.
Rigging up a HD continuous duty solenoid is pretty easy, but you could just add another battery in the engine compartment, in parallel, and not worry about isolation.  You'd in effect have two batteries to discharge, two to charge, and two to start the Van.  I think in another thread you said you already have, or will acquire, a jumper pack, so the chances of being stranded are close to nil.
Technically, batteries charged/discharged in parallel should be the same size, make and age.  Mismatching old and new batteries, tends to age the new battery quickly.  Ideally, you'd replace both batteries at the same time  with the largest marine batteries which could physically fit, and have twice the battery capacity, and twice the cold cranking amps to work with.  Even if you drained both batteries significantly, 2 of them together can still start an engine.

 

[LeeRevell]

+2 on the car chargers. I use one for my cellphone when traveling, another for my digital camera, and one for my GPS. Each needs a different tip. I have had the phone and GPS chargers going at the same time.
I do have a small 400W inverter with a USB port, but have not used it yet.
My newest jump start unit is a larger unit that also has USB port. So I am pretty well covered for roadtrips without needing a house battery.
No room in the minivan engine bay for a second battery, but with some creative modification I should be able to put a secondary battery in the engine bay of my E-150.

 

[Theadyn]

Already have car chargers and one of those that inverts from 12v to AC power if needed. And yes, there is already the wiring sitting right there looking for a plug in. Was just wondering which way would work better. Just a second battery put in and plugged may just be easier and smarter.

And yes, already have the battery jump pack sitting here charged and waiting. So that makes sense, just jump start it with that if for some strange reason I run them both down. There are two 12v plugs already installed at the back near where the bed is, one inside a cabinet near the TV, and of course, the one in the dash.

So... just need to, today, go check out the back plugs and see if they work while the engine isn't running. One of my pet peeves is to be into a movie and the battery dies, haha... It would be nice to know I can plug the laptop into the inverter into the 12v plugin right there by the bed.

More things to check out and think upon... thanks guys!!!!

 

[SternWake]

Knowing van conversion companies, the 12v plugs in back will be hot with the engine off, but they will be wired with 16 or 18 awg wire.  At those distances from the battery, the voltage drop might be enough to trigger the low voltage alarm on the inverter.

The higher the load, the more the voltage drop..

  So while it might be ok powering the laptop when the laptop battery is already full, the extra 3.5 amps required to charge the battery could be the straw which broke the camel's back 

A simple voltmeter can tell you a lot about the battery state of charge, although it cannot be considered very precise.
http://www.amazon.com/INNOVA-3721-B...UTF8&qid=1422373657&sr=1-8&keywords=voltmeter

Harbor freight sells a digital multimeter for very little $$, sometimes even free with other purchase, and these are a very good tool to have for checking for voltage or continuity.

The car charger for the laptop can be uptp 50% more efficient than using an inverter to power the original power brick. Many variables affect this number, but it is one of the best ways to conserve battery power, along with LED lighting.  Most every incandescent bulb has a plug in LED equivalent.

 

[LeeRevell]

Fortunately I did get a 12V car charger cable for my laptop. I'm good to go for shorter road trips. I'll have the house batteries installed, along with solar by the time I am ready for longer trips. I want the second battery in the E-150's engine bay as an emergency starting unit primarily, and for initial accessory use til the house batteries are done.

 

[SternWake]

If adding another battery that is much different in age and make, one can add an easy battery disconnect switch to one or both of the batteries, as it is not ideal to leave two batteries of different age and condition in parallel permanently

Get to camp, and manually disconnect one battery entirely from any discharging, and have that as a backup for engine starting

http://www.amazon.com/Post-Battery-...sconnect&pebp=1422376242324&peasin=B001N729FS.

It would be preferable to have 2 marine batteries of the same make and age and condition, but we do not live in an ideal world.

Having a lot of CCA available to crank the starter is pretty neat. My Northstar AGM battery has 930 CCA, and even when overnight cold, takes less than half a second to start the engine. If the engine is already warm, the merest blip of the starter does it. My flooded Deep cycle battery is rated at 620 CCA, and is Not impressive in this regard, but it was not designed to be.

 

[akrvbob]

I would definitely recommend setting up a house battery and connecting it through a continuous duty solenoid. You don't want to rely on just your starting battery.

Heat and cold are the only reasons not to mount it under the hood and unless you are going to be extremes of either I don't think they are an issue.

Wherever you put it, I highly recommend a house battery with everything wired to it and not the starter battery.
Bob