How (not to) overload the Charging System of a GSX1400

[gsxbarmy]

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How (not to) overload the charging system of a GSX1400

I guess we've all added electrical items to our 14's (or some of us have) in one way or another, either by running heated grips, or Sat Nav's, or similar and have changed indicator/tail lights to LED, uprated headlamps to HIDS, alarms, PCIII's, etc etc etc. All extra load on the battery and charging system (perhaps!)

However - I guess the battery/generator has a finite limit in what it can / cannot support..........

So - how do we know if we are overdoing it or putting too much load on the system - or don't we have to worry? What would the symptoms be if the system was overloaded? Would the system would cope because there's a decent "comfort factor" built in?

Our very own “Q” provides insight………….

A quick test to check if all is well (or not!)
•   Put a voltmeter across the battery terminals set to measure voltage.
•   Note the voltage reading.
•   Turn the ignition on â€" the voltage reading will drop.
•   Start engine and note voltage again - preferably at 4000 to 5000 rpm
•   The voltage should have immediately started increasing once the motor starts - if it does not, you have a problem.
•   With all your accessories switched on, the voltage should not be continually falling.  If it is, your alternator is not keeping up with demand and will suffer long term (possibly failing quite quickly depending on load)
•   When charging, the battery terminal voltage may reach 13.8-14.5v but not much higher, if it does it may boil the electrolyte.

Also - reading up, the alternator is rated at about 300-330Watts - which in turn is about 25A to 27A depending on measured voltage. (Amps x Volts = Watts)

So let’s add it up…
•   Remember a single 55W Headlamp Bulb will draw about 4.6A
        o   For those that have replaced with high power 110W bulbs, watch your wiring - you're probably drawing nearer 8 to 9 Amps on that alone)
        o   If you've fitted twin Bates or similar, then again watch your wiring - then 110W will mean 9A! And if you hold the pass switch so high and low are both on, another 8-9A too!!!). So Twin Bates with hi-power bulbs will be drawing 16 to 20A or so - 66% of all available alternator output.  If you've not run wires directly to the battery you will likely cook the headlamp feed and if you check you will probably find all the feed conductors are blackened. However swapping to HiDs on the Bates  works very well in my experience and still less than 8A when running
       o   On the plus side for those who have fitted HiD Headlamp conversions, they generally draw less than the filament equivalent, with a HiD system drawing about 1 to 1.5A less than the normal 55W H4 Bulb
•   Brake lights will add another 42W when braking so about 3.5A there. 8A so far.
•   Fuel pump and engine management are likely to draw up to another 3 to 7A depending upon rpm etc.
•   Heated grips do not draw a lot of current - maybe 2-3A tops!
•   Heated clothing can soon add up, can easily be 3 to 5A per person depending upon what is actually heated.
•   Sat Nav's, phone chargers, Oxford Oilers etc - less than 1A each so negligible

So - In reality, it only really becomes a problem when you stick lots of additional filament lighting on - remember every 12W is 1A of load.  If you add Twin 'Driving' lamps (as I've seen sometimes on crash-bars, you're probably adding 110W (55W each) which is 33% of your total available alternator output!!)

You can get alternators wound to give increased capacity, but be careful there too, because it all has to be rectified to make the AC output DC, so watch your rectifiers as they are known to suffer sometimes even on normal loading.  It may be possible (but I haven’t looked) to get a higher rated version of that too but definitely worth considering if you're changing your windings to higher ratings.