battery charging and sterling charger

Fergus

Fergus

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I have a problem with my setup and would like some advice please! I had all batteries replaced (3X120ah) because they were not charging. Still same problem - only about 4amps max going in and just under 13v even though only 58% charged. The charge % has been steadily dropping in spite of using the engine. When off no current drain shows on the battery monitor. I took the sterling unit back and they replaced it foc! Installed the new one - same problem. All the leds flash. It presumably worked with the previous owner but the sense cable (red) is connected to the pos alternator output rather than the battery itself. I'm at a loss - could be the battery monitor getting in the way? BTW also seems sluggish charging on shorepower..
 
You either have a knackered alternator or a wiring problem. There is no way anyone can diagnose your fault by e-mail. You have to first determine there are no wiring problems in the normal circuit. A good indication is, does the charging light come on before you start your engine and go out when started? If so without the stirling attached you should get a "normal" charge. If the light works but the charge rate is down although there is a trickle charge there it is probably an alternator problem. The stirling unit can only do it's job if the alternator aint knackered in the first place.
 
Do you mean a Sterling Advanced Alternator Regulator...or is this a mains charger unit? From your description I assume the former. The sense wire definitely wants to go as close to the battery +ve as possible (that's the point of it). And it sounds like a wiring or system fault if all the lights are flashing. But it also sounds like you have little output from the alternator itself, and maybe that's where the fault lies? There's lots of people on this forum who can help, but I think we need some more clarity on your setup.
 
Yes it's a Regulator (4 step). The manual says that if all lights are flashing there is excess voltage (?) and too much current drop between the alternator and the battery - so wiring or battery condition monitor causing this? However still only getting 4 amps - what would a "normal" rate be?
 
With discharged batteries you should get well into double figure Amps...probably 30+ shortly after start-up. You may well have a big voltage drop in the wiring causing the high voltage alarm to go off (flashing lights), but first I'd suggest a) move the battery sense wire to its correct position b) check the wiring for poor connections / cable - and anything getting hot c) get the alternator checked. It does sound like the latter, but the Sterling unit flashing implies something else is wrong.

PS - are you sure it is the battery sense wire is connected to the alternator? I ask because if I recall correctly the alternator high voltage alarm wire goes here? Might you have confused the two?
 
A small contribution to this, but if you suspect your alternator isn't working properly ( and the Sterling kit won't mend a faulty alternator) then take take it off ( carefully note where all the wires go !!) and take it to an auto electrician ( one man band in a small indsutrial unit) and the will test it and replace anything faulty. Much cheaper than using a marine place.

Regards

Andrew
 
Thanks for all the advice - am I correct in assuming that when all lights are flashing the regulator has in effect removed itself from the circuit and the batteries should be getting whatever the alternator is putting out?
 
Confession time for me... chased my tail round in circles for two days with a very similar problem.... couldn't seem to get any charge no matter what i did. Finally discovered an auto bilge pump, wired in seperately before all the breakers so it would always be on, had run dry and seized in the on position. little motor trying to turn seized pump meant 30 amp draw and almost boiling bilge water!! would suggest making sure that everything on board is definitely off before checking charge rates... I know i will in future!!
 
Spent a while talking to some very helpful people from a Volvo agent - said didn't sound like alternator was the culprit, and to be highly suspicious of battery monitor devices. I have no electric bilge pump (yet!)
 
They might have a point. How do you know your batteries are discharged? Is it only via the battery monitor? Check SG of the electrolyte and open circuit voltage some hours / days after charging. If the SG is >1.25 and the voltage is 12.7 - 12.9V then maybe you have fully charged batteries (and that WOULD explain only 4A going in)...worth a try. HOWEVER it doesn't explain the flashing lights on the Sterling.
 
I have just suffered from this same problem. It turned out that the batteries (4 x 100 Ah in 2 banks) were connected using the screw type clamps on the batteries. These were only transmitting low ampages. I replaced them for proper crimped ends (at the same time I rewired with heavier cable) and hey presto - problem went away.

Symtoms were that the fridge wouldn't run, Engine would only start on the engine set not domestics, Lights dimed a lot when the pressure pump operated etc.

I too wasted money on a new bank of batteries - there was probably nothing wrong with the old set!

Once this is sorted - then you can start work on installing the Sterling - Good luck.
 
You need to check the wiring, the red wire from the sterling unit should not be on the alternator, extend this wire to either off your batterys and try again, if this fails look on the stirling website under downloads and you will find a new manual for setting up and fault conditions for your unit.
If it keeps flashing all the lights then you will have to go through all the connections from the sterling and also check the positive output cable from the alternator and the engine negative cable.
 
OK - had a sparks down on the boat, rewired sense connection to the battery and checked all other connections, no difference. Looks like the alternator's the culprit so now waiting to hear back..
 
Alternator diagnosed as totally bu88ered - reconditioned replacement unit now fitted and all systems in the pink!
 
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