TRCM
NAXJA Forum User
- Location
- Newport News,VA
kunaji said:I'm certainly no EE, but you are making no sense at all. Whether the alternator is hooked up to the battery or the PDC, it's providing power in the same way to the same places.
Does which side of a wire you tap for an accessory matter? If both sides of the wire are hot then it does not, all other factors being equal. I would assume the same thing holds for the charging side also.
Look at the example I gave of my laptop computer.
And here's another one.
You have a power plant that is water driven by the river. Upstream of the power plant, the river forks and then rejoins, so there is an island there. As long as the river is flowing, you make power right ? Well, lets say you have to build a bridge across the river. And you have to dam the river to do so. Well, if you build the bridge across the island, since you have 1/2 of the rivers flow on each side, then you can dam 1/2 of the river on one side, then when that 1/2 of the bridge is done, you can remove the dam and block the opposite side. Doing this, you will always have at least 1/2 of the rivers flow to the power plant.
Now, if the river does not split, to build the bridge, you will have to cut off ALL of the rivers flow to build, hence no power from the powerplant.
Apparently, you don't know how a charging system works. The alt supplies the vehicle loads AS WELL as the power to recharge the battery. In this case, the alt could well be supplying 2x as much to the vehicle as it is to the battery, so no, it's not providing power to the same place in the same way.
If I connect a winch to two different power sources (same as in the middle of a wire), where the two power sources have different ratings, the power supplied to the winch is gonna come from the higher rated power source, not both. This is the same reason you never put 1 good battery and 1 bad battery in your flashlight. The power will only come from the good battery, because the power output will equalize.
You don't want to connect a fully loaded 8 MW generator to the same bus as a partially loaded 8 MW generator. If you do, the loads will rapidly even out, and in the process, you will most likely damage something pretty bad. You must even out the loads before you connect them to prevent damage.
As to which side of the wire you tap for power, as long as ONE side of the wire has power, the item you are adding will also have power.
As to the alt being connected to the battery or the PDC, yes, it is providing power, but NOT in the same way, or at the same rate or current.
You can not charge and discharge a battery at the same time, which is what you will be trying to do if you connect straight to the battery. BUT, you can supply current to the vehicle AND the battery at the same time, because to the alt, the battery is a load when connect as it was from the factory. If the alt goes straight to the battery, then you will drain the battery lets say 10% when you start the vehicle. Once the vehicle is running, the alt will supply the loads of the vehicle by supplying only as much to the battery as is being drawn off. This means the battery WILL NOT charge, and since you can't have the alt working if the engine is not running, when you turn the engin eoff, the battery will be down 10%. And the next time it wil be 20%, and so on, and so son. The battery will slowly die.
The VR senses line voltage in the vehicle, and adjusts the alt output to match that plus a small %. That small % is what normally charges the battery. If you run the alt straight to the batt, and do not relocate the VR sensing point, then you will run off the battery voltage to supply the vehicle, and the VR will adjust the alt to that voltage. Now, doing this, you lose the extra voltage for charging the battery, but you will supply the vehicle.
The reason this works in boats for so long, is most people hook a battery charger up to their boat on a slow trickle charge when it is not being used.
Last edited: