Driftgate X-port charge splitter

[Scottish Spanner]

Hi folks can anybody advise please ? We have 2 alternators feeding the Driftgate 2 input / 3 output x-port charge splitter with separate banks of house and engine batteries. Checking the current being drawn from each alternator to each input of the X-port with a clamp meter showed around 36A from Alt 1 and 3A from Alt2 to input 1 and 2 respectively. My guess is the control algorithm in the X-Port will determine the “routing” of charge to the batteries but I would have expected the loads on each alternator to be similar. Therefore, not sure if Alt2 is pumping in lower current due to design of the x-port and is OK or there is a fault with either the alternator or the x-port. Has anybody experience of similar setups and how load across alternators is managed?
Thanks!

 

[Oily Rag]

Are your alternators boosted or controlled by any other Driftgate products, such as X-Alt Skipper or Captain?

If so, is it possible that one alternator has reverted to "normal" mode, with no boosting of output?

 

[halcyon]

Hi folks can anybody advise please ? We have 2 alternators feeding the Driftgate 2 input / 3 output x-port charge splitter with separate banks of house and engine batteries. Checking the current being drawn from each alternator to each input of the X-port with a clamp meter showed around 36A from Alt 1 and 3A from Alt2 to input 1 and 2 respectively. My guess is the control algorithm in the X-Port will determine the “routing” of charge to the batteries but I would have expected the loads on each alternator to be similar. Therefore, not sure if Alt2 is pumping in lower current due to design of the x-port and is OK or there is a fault with either the alternator or the x-port. Has anybody experience of similar setups and how load across alternators is managed?
Thanks!

Have you checked the output voltage of each alternator with the above test ?

If one is say 14.2 volt regulation and one 14.3 volt, if the higher one is running at 14.3 volt, the 14.2 volt unit will be shut down or close to. X-spli is basically a solid state VSR.

Brian

 

[Scottish Spanner]

Are your alternators boosted or controlled by any other Driftgate products, such as X-Alt Skipper or Captain?

If so, is it possible that one alternator has reverted to "normal" mode, with no boosting of output?

Hi - no both Alts are configured with the internal regulators.

 

[Scottish Spanner]

Have you checked the output voltage of each alternator with the above test ?

If one is say 14.2 volt regulation and one 14.3 volt, if the higher one is running at 14.3 volt, the 14.2 volt unit will be shut down or close to. X-spli is basically a solid state VSR.

Brian

Hi Brian - I checked but can’t recall the voltages being materially different; I will check this again. The house battery was about fully charged, the engine battery had just been used so would have been charging, nav, comms and other electrical equipment would have been drawing 10a from the house battery however the Mastervolt shunt was showing net outflow of current from from the house batteries so no appreciable load being taken up by the alternator whilst the engine was running.

 

[TernVI]

Your measurements suggest a lot of current must have been going into the engine battery.
That would probably fall quite quickly, so the measurements may not really be valid in terms of being simultaneous.
It's quite hard to get two 'identical' things like alternators to share a load properly, if they are not notionally identical, it gets harder.
Provided neither alternator is really heavily loaded, it may be a waste of time trying to make them share the load.
Are they on the same engine?

In general, I don't think I'd expect to see a discharge while the engine was running, unless a heavy load was applied, but it may be that the charge combiner has a delay, to prioritise the engine battery for a few minutes (?) before connecting the house battery? This gives the drive belts a much easier life.

It might be worth measuring some voltages, particularly checking for differences between alternator outputs and batteries, cable drops, variations in the erstwhile 0V cables and busbars etc.
A few 10s of mV can make a difference to the current flowing if the batteries are large.
Switching the meter to AC volts can show if there is lots of ripple about, which can confuse the DC measurements.

Clamp ammeters can be inaccurate due to stray magnetic fields and so forth. I use them as an 'indication' more than a precise 'measurement' .
A 5A error on the 200A scale wouldn't be a surprise.

 

[Scottish Spanner]

Hi, thanks for the detailed replies, all very helpful. I will make some more checks as suggested next week when we are next out and update the thread. Without knowing the algorithm or logic the X-port is using to manage alternator demand it is difficult to determine if it’s all working correctly but I will see what a more detailed analysis of voltage / current data suggests. If in the meantime anybody has any info as to how x-port does this please let me know. There is no info on the archive Driftgate2000 website and unfortunately the company has long since ceased trading. Many thanks
Richard

 

[pvb]

Do both green LEDs on the X-Port light up when the engine is running?

 

[pvb]

The house battery was about fully charged, the engine battery had just been used so would have been charging, nav, comms and other electrical equipment would have been drawing 10a from the house battery however the Mastervolt shunt was showing net outflow of current from from the house batteries so no appreciable load being taken up by the alternator whilst the engine was running.

This suggests the charging of the house battery is faulty.