Jump to content

x-eng split charge


stripy

Recommended Posts

this may be a daft question........

how does the x-eng split charger work.

i have just put 2 batts in my 200tdi 90 with the split charger and what i get is ..........

with the engin runing, main batt shows its charging at just over 14v while the winch batt also shows just on 14v

with lights, heater, wiper, just about every elecy runing, main batt shows 13.85ish volts & the winch batt shows 13.7 volts.

i thought the battery which is taking the most volt draw got the charge, am i wrong.

the batteries are both optima yellow tops & were full charged when i fitted them.

Link to comment
Share on other sites

i thought the battery which is taking the most volt draw got the charge, am i wrong.

First, a quick lesson -

Current is measured in Amperes or Amps (abbreviated to A). This a measure of the rate of flow of electricity (similar to water in a pipe)

Voltage (or "potential difference" in older terms) is measured in Volts (abbreviated to V). You can think of this as the "pressure" of the electricity, also like in a water pipe, but don't tell my lecturers I said so :ph34r:

You can have a voltage and no current (like 14V in the battery but the battery not connected) just like there is pressure in the tap when the tap is turned off.

Just to complete the picture, resistance (Ohms, symbol like a horseshoe) is a measure of how hard it is for the electricity to flow. Batteries have an internal resistance, which is why the output voltage (pressure) falls when you load it up (draw a lot of current, or turn the tap on).

The same applies to your alternator and the split charger, what you're seeing is the pressure level in the batteries with the tap turned on from one, but both being filled from one pipe if you follow (the loaded battery is dragging the charger voltage down on both batteries because the split charger can only source so much current from the alternator).

I need a lie down ... :)

Link to comment
Share on other sites

The X-eng split charge, like most out there, just connects the two batteries together. Nothing more clever than that.

You will see differing voltages at the batteries due to how they are wired (every joint will have a resistance, which with current flow will cause a voltage drop) but also due to the fact that no two batteries are the same.

There is no intelligent distribution of charging current, the split charge is just a relay, which is just a switch, at the end of the day.

Link to comment
Share on other sites

is there some way of checking thats its working correctly.

Yes, your voltage readings pretty much confirm all is well.

I would check that the current carrying wires are all well terminated and bolted down, any resistance will cause significant voltage drop, and generate heat.

Link to comment
Share on other sites

is there some way of checking thats its working correctly.

You've got readings for both batteries with engine on, no load

You've got readings for both batteries with engine on, loads of load.

If you leave the load on and stop the engine, you should find that the second battery is sat at around 12V+ and the main battery will be a lot lower, because of the current draw. If it is, then I guess all is OK.

Last check (having turned all the lights off!) is to load the second battery instead and see what voltage reading you get.

Restart and you should see both batteries showing a lower voltage. A battery being charged will show a lower voltage to begin with, increasing until it's full, which is how automatic chargers "know" - it's that damned resistance again.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy