I am having some power issues, power drain, with my plowtruck. Only time I have a drain is when I am using the plow. It's an 05 F-250 FX4 with a 5.4 engine. Does anyone know what I would need to put a second battery under the hood, sort of like a diesel setup? i.e. tray, cables etc. Part numbers would be helpful too. The dealer my company deals with is useless and won't look anything up at all so I need help with this one.

 

Oh, does the positive cable from the second battery just get tapped onto the positive post of the first?

 

Your battery is only there for you to start your truck. Once the truck is running the battery is just being charged to be ready for use again when your engine is not running.

You say you are having problems when using your plow...I would look into upgrading your alternator.

Here is a thread on adding a second battery:

https://www.ford-trucks.com/forums/9...ry-system.html

Here's a tutorial on adding a second battery (warning, it's on a chebbie)

Dual Battery System www.pullig.com

 

I don't even know what size alternator is in this truck. So, I should upgrade the alternator?

 

well if you're using a lot of electrical, then an upgrade is probably what you do need. However you still need to know what your stock is, then look at the next level higher .. I'm guessing your stock is in the 80-110 amp range .. a 135-165 amp would probably be what you need.

 

Like stated the battery just for short term draw, the charging system should handle most of the regular draw. To start on the upgrade trail, pick up some 4ga wire. You should run a 4ga wire from the alt to the battery, another from the motor to the body and one last one from body to battery. 4ga will do until you get into the really big alternators and such.

Try that up grade first, it's commonly called the big three and should help providing your draw isn't that much more than the alt produces. If you still need an upgrade, Alts are available from 110amp (which is the stock replacement) upto 230 amp. I have the 230 and used 1/0ga wire for my big three.

There are several ways to conquer adding a battery. You can do it like the diesel and just wire them in parallel (pos to pos and neg to neg), the down side to this is if one battery starts to fail it will drag the other down even with everything off. You can add a solenoid and connect the two batteries only when running or by a manual switch, like the direct parallel, though you still run the chance of cooking one battery while trying to charge the other. The last way is to use a battery isolator. The isolator is a huge diode pack and isolates one battery from the other, basically you use one battery for the normal truck stuff, then the isolated battery for your accessories.

If I do duals, I am going to use the solenoid. I will wire it be connected with the key on using a source that has power during cranking. This way, when the key is I have both batteries and can crank off the battery that was disconnected.

 

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THats for the drivers side battery tray. just bolt it in run a pos cable across the two batts then a neg cable to the body and your done. i also had to cut off one of those big humps on my intake and then i sealed the hole with some electrical tape wrapped around it a few times. when it gets warmer im gonna epoxy a piece of plastic there. Also the way my plow was set up the solnoid was on the drivers side fender then the cable ran over to the pass side battery so i just used that as the cable and hooked a short one from the new bat to the solnoid.

 

Here' how I did mine: https://www.ford-trucks.com/forums/4...info-here.html

 

You probably need a larger alternator. You only need a second battery if you are having cold start issues and not able to develop adequate cranking speed.

To size the alternator just turn on your truck with lights, heater, plow, and all other continuous loads running. Let it idle. Since we know the alternator cannot keep up with the electrical system then all you have to do is measure the current output of the alternator, and the current leaving the battery. The sum is the minimum output the new alternator must generate at idle to keep up with electrical loads. Give yourself another 10A charging capacity for each battery, per SAE J180 specification.

Call up a technical help line from the place you want to purchase the alternator. Ask for an alternator that will deliver ### Amp at engine idle. The nameplate rating will be much higher since the alternator can deliver more current at higher speeds. Size the charging cables to the battery so that the voltage drop of the charging circuit does not exceed 1.0 V.