voltage drop.. is this normal

[becareless06]

With out engine running 12.5 volts. With engine. Runing holds 14 volts
With connex 3300 an Texas star Dx 500 I've seen as low as12.3 on long keys
My truck is. A 1999 Ford superduty 2 1000 cold cranking amp batterys

I'm. Runing 10 / 2 house wire for power wire. Would it be benifical to upgrade to 4 gauge
Do you guys think that would help the voltage drop

 

[binrat]

Depending on the distance I would say the min of 6 guage, but if you can afford it, 4 guage wire. Also replace the wire from the alternator to the batteries as well.

 

[Robb]

With out engine running 12.5 volts. With engine. Runing holds 14 volts
With connex 3300 an Texas star Dx 500 I've seen as low as12.3 on long keys
My truck is. A 1999 Ford superduty 2 1000 cold cranking amp batterys

I'm. Runing 10 / 2 house wire for power wire. Would it be benifical to upgrade to 4 gauge
Do you guys think that would help the voltage drop

Hardwire house wire?!? Like Romex?!?

Try some fine-stranded 6ga wire instead.

IIRC, fine stranded wire will carry more DC current than solid wire will. House wire is for AC use. More surface area on stranded wire than on solid wire. Current flows on the outer part of wire; called 'the skin effect'. More strands; more current to be conducted. Don't forget to have fuses inline too.

Even if you have two batteries and are seeing a voltage drop; it means that you are still draining your reserve. Perhaps bad battery connections. Most charging systems in car cycle the battery charge between 12.6v (alternator turns on at this point) to 14.4v (alternator turns off at this point) . Better check your charging system and the condition of each battery.

 

[becareless06]

the charging system was just checked and condition of battery were ok also. im going to try the 4 gauge wire. and see if that dosent help my problem. what size fuse should i get ?

 

[Robb]

the charging system was just checked and condition of battery were ok also. im going to try the 4 gauge wire. and see if that dosent help my problem. what size fuse should i get ?

Whichever fuse that Texas Star recommends for the amp you use.
Best to use the right size.

 

[unit_399]

BeCareless -

Anytime you run an amp of 500 watts or more in a mobile, you must beef up the charging system, or your amp's output will suffer. First, run a #6 stranded wire from the alternator output directly to the battery positive terminal. Leave the stock wire in place. It won't hurt anything. Use stud-type battery terminals: Brass or copper-bronze on the positive, zinc plated brass on the negative. Replace the stock negative battery cable with a braided cable. Any good auto electrical shop will have them. IMHO get some #6 arc welding cable at a welding supply house. They will usually cut it to length, and they have the tools to crimp the terminals on the ends. Don't solder the terminals, as this makes the wire brittle and eventually a connection will break and you'll have a no-fun fireworks display under your hood (I speak from experience). After everything's installed and running, if you still see an excessive voltage drop or your headlights dim down a little at night when you're keyed up, add a 1 or 2 farad car stereo stiffening capacitor to provide some extra current reserve. I know this sounds like a lot, but if you want that DX500 to perform 100%, you can't cut corners. 73s

- 399

 

[Beetle]

Hardwire house wire?!? Like Romex?!?

Try some fine-stranded 6ga wire instead.

IIRC, fine stranded wire will carry more DC current than solid wire will. House wire is for AC use. More surface area on stranded wire than on solid wire. Current flows on the outer part of wire; called 'the skin effect'. More strands; more current to be conducted. Don't forget to have fuses inline too.

Even if you have two batteries and are seeing a voltage drop; it means that you are still draining your reserve. Perhaps bad battery connections. Most charging systems in car cycle the battery charge between 12.6v (alternator turns on at this point) to 14.4v (alternator turns off at this point) . Better check your charging system and the condition of each battery.

"Skin Effect" is negligible at 60 Hz. At HF it becomes a necessary consideration; the higher the frequency the more necessary. Some coaxial cable used on long runs on Navy ships has just a hollow semi-flexible copper tube for a center conductor. Reduces cost per foot (and weight per foot!)

 

[Robb]

What is a stiffening capacitor?
A stiffening capacitor is an extremely large value electrolytic capacitor. Capacitors have the ability (capacity) to store a charge on their "plates". The larger the capacitance, measured in units of Farad, the greater the charge a capacitor can store for a given voltage. Most automotive capacitors can store a charge at 16 to 20 volts, and are rated from about .5 Farad up to 2 Farad or even more. Capacitors have an extremely low internal resistance to current flow, much lower than that of a battery. Capacitors can therefore charge and discharge power much faster than a battery can.

How does it work?
All capacitors consist of two "plates", separated by an insulator called the "dielectric". Each plate has an external connector. Connected to a source of voltage, electrons are forced onto one plate, and off of the other plate. When the capacitor is fully charged, no more electrons will flow in or out. Disconnected from the source of voltage, the charge will remain between the plates, and the voltage can be measured between the capacitors terminals with a volt meter. A capacitor can store a charge for a very long time.

The capacitor is connected to the positive power line to the amplifier, and then grounded to the vehicle chassis. When initially connected, the capacitor will very quickly charge up to the voltage of the vehicle's battery, usually a little over 12V.

 

[W5LZ]

It's always good to reduce resistive losses so going to a larger sized supply line to the battery would be a good idea. It never hurts to have a cable too big, it always hurts to have one too small.
From what you've described, your alternator isn't capable of keeping those batteries charged when transmitting (along with all the other draws by the truck's systems, whatever is 'on'). It may be operating correctly, it's just not large enough.
A capacitor to 'stiffen' the current draws is just not going to work with this sort of thing. It works fine with audio, but not for a continuous and large DC draw. If you take some charge out of that capacitor you have to refill it or it just goes dead. Same draw from the current source, the alternator. It's a timing thing. Then there's the fact that very large capacitors are also very dangerous. If their voltage rating is ever exceeded, they tend to make very loud noises when they blow up. That doesn't say anything about destroying what's near them when they do. A typical surge that's fairly common in most electrical systems can make for very pretty fireworks displays, pay your insurance up! (That's not a joke, BTW.) Those 'stiffening' capacitors are not of benefit in a primary power situation, and will not compensate for a too small current supply source.
- 'Doc

 

[binrat]

For my old 05 GMC Sierra with a 145 amp alt, I had dual battery, 6 guage running from the alt to the batteries, 6 guage running from the second battery to the radio / amp (7' long). My radios powered were an icom ic2200h, and optima w/ dx500 amp. Only had a problem when high beams were on and a long key. (high beams lights were aftermark 110 watt jobbies as well)

 

[The Jerk]

A stiffening capacitor will only help take the peaks off the draw...basically it does more to protect the system from spikes than it does to help with output. In the OP's case, it won't help a bit because he needs storage capacity, which a typical capacitor has very little.

I ran a 1F capacitor with both my straight 4x1446 and my 1x4 (all 2879s), the benefit was only noticed on SSB where you have no power "draw" from a carrier, and from zero to full modulation during transmit. Before installation, the headlights would dance with modulation, after installation, not so much. It didn't seem to help a thing on AM transmit, but I had a better PEP on SSB, probably because the capacitor located 12 inches from the amp was able to provide that instantaneous juice during modulation.

On edit: this system was in my last truck...it had a single 160A alternator, 4ga wire between the batteries and alternator, dual 1550CCA batteries, and 4ga power leads to the amplifier. And without the capacitor, my lights would dance.

 

[becareless06]

Ok here's a stupid question if I'm going to do this for 500 watts wat would the wire size need be for like 2000 I am in the future going to be goin bigger I know I will need a second alt and battery bank

 

[psycho]

With out engine running 12.5 volts. With engine. Runing holds 14 volts
With connex 3300 an Texas star Dx 500 I've seen as low as12.3 on long keys
My truck is. A 1999 Ford superduty 2 1000 cold cranking amp batterys

I'm. Runing 10 / 2 house wire for power wire. Would it be benifical to upgrade to 4 gauge
Do you guys think that would help the voltage drop

You have a 130 or 95 amp alternator and a TS 500 will draw as much as 60 amps. You will get voltage drop no matter what wires you run to the amp. I would run #4 and if you want to upgrade to a larger amp down the road you might try #2. Those big cased alternators can be built up to as much as 240 amps.

 

[mechanic]

You have a 130 or 95 amp alternator and a TS 500 will draw as much as 60 amps. You will get voltage drop no matter what wires you run to the amp. I would run #4 and if you want to upgrade to a larger amp down the road you might try #2. Those big cased alternators can be built up to as much as 240 amps.

This is the best reasoning solution.... a bigger output alternator for this draw.

73 mechanic

 

[becareless06]

That's what I'm thinking . But I'm going to upgrade the wire first