D40 alternator clicking after secondary batteries charged via caravan.

[flashum1]

Hi all, I.know it's a weird thread but hopefully it'll soon make more sense.
Anyone had any issues with dual battery systems? Got a d40 navara in which I have installed a red arc smart start isolator and agm batteries in the tray. All has been going good running rear lights and fridge until I decided to help charge the batteries via the caravan system which was plugged into 240v. I had wired the supply from the car to secondary batteries via an andersen plug so it could be disconnected and Andersen charge lead from caravan could be ran directly to rear batteries without charging crank battery or interfering with and vehicle electronics. This worked fine, and left overnight to charge. I disconnected lead from caravan and reconnected car dual battery plug the next morning and drove about 3km without van no problems, fridge running for about 2 hours. Got back to van and hooked up, 12 pin too for fridge aes and when I started car there was a random clicking noise coming from the engine bay. Inspection found it to be coming from the alternator, so I disconnected dual battery Anderson plug and it went away. Is it possible that the caravan battery management system overcharged agm batteries causing the alternator to have an overcharge fault? Thinking that although with the fridge running for 2 hours it would have drawn from this charge. Multimeter is buried in the back of the ute and with daylight hours depleted I was found to wait until tomorrow to further investigate. Caravan battery system set to agm as van battery is and charging no higher than 14.4v which would be acceptable but why only fault when caravan plugged in? Any ideas?

 

[Old.Tony]

It's unlikely that the charger in the caravan overcharged the AGM battery but even if it did, it should not have affected the alternator.

Mains chargers can run "equalisation" charge modes which bring the voltage up to >15V which causes the individual battery cells to balance themselves. 12V batteries have 6 cells, and if one cell has only 60% of its capacity then the entire battery will perform like it has 60% of its capacity.

Even an equalisation charge shouldn't cause problems with the battery system (since they're not designed to).

Even if the battery in the camper was dead flat it shouldn't cause drama with the alternator unless the alternator was struggling anyway (eg worn brushes, some other damage). Batteries will take as much as they're given and as much as they'll balance each other in a parallel system (often to their own detriment) they shouldn't overdraw from the generator.

I would be wondering if there's any cable damage or crossed cables somewhere. If not, then if the caravan's trying to draw a lot of current from the car, I'd wonder about the regulator.

What happens with the van not connected, engine running, every vehicle light turned on and plug in some loads to the cig lighters? I have a 10A ceramic heater that makes a great load, can you find something like that? It's a total waste as a heater (ie it was a waste of money, it'd create more heat if it caught fire) but it's brilliant as a constant load.

 

[flashum1]

Secondary batteries in car went flat overnight with fridge running at -7 (empty tho). I reconnected dual battery plug and started car with van connected too, no alternator noise. Travelled about 150km touch wood with no issues. Have been parked for about 3 hours now and fridge still running, now set at -4 but still empty. I might just only use Andersen charge lead when in solar charge and not 240 and see how it goes. Fingers crossed.

 

[Old.Tony]

Any idea what might have caused the issue?

 

[flashum1]

Got me snafoo'ed? Fridge still running now, must be like 9 hours since car was only running for 2 hours max. I can only assume charge in aux batteries was too high which stuffed with alternator regulator but as van battery management was sat at 14.4v I cannot understand how? I'm just going to have to keep an eye on it? Will be pulling up at muswellbrook on Wednesday for a couple of days so I will investigate charge rates and alternator output then.

 

[Old.Tony]

Lead acid batteries won't hold a high voltage for long. If you charge them at 16V (they'll fizz like the bloody blazes) they'll drop below 14V fairly quickly after removal from the charger. I don't think they'll be causing feedback issues especially over a cable - the voltage on the front of the cable is likely to be at least 0.3V less than the battery is holding, and if you're using 6mm cable it could be as high as over a volt (of loss).

 

[flashum1]

Yup. All agm except for crank battery. I think it was 4 b&s cable I used from front to back but not using start override feature of solenoid so not a great deal of voltage drop, I think from memory only around half volt. I can't work it out but I'll probably organise a spare alternator just in case, don't wanna get stuck 300 km from longreach needing one and I'll probably look into a more hi tech dual battery system.

 

[Old.Tony]

That's the reason why I just invert+mainscharge mine. Aux battery type doesn't matter one bit, it draws about 7A to provide a 6A charge plus the occasional 1.5A to turn the fridge over and only while the ignition is on.

To charge from the van, I run a 240V lead from the side of the van into the tub and just move the plug from the front of the inverter into the extension lead. And remember not to drive off while plugged in, of course!

 

[flashum1]

Started car this morning and heard a couple of random clicks, turned headlights on high beam with driving lights on and clicking more. Charge tested at 14.6 at crank battery. Disconnect driving lights and clicking almost completely stops. Disconnect dual battery plug and clicking completely stops. Could we be drawing more than the 130 amp alternator can supply? Or is it more likely a fault in the hids?

 

[flashum1]

Finally found an auto electrician who could make the time to have a look at alternator. He knew exactly what the problem was, failing clutch pulley on alternator. Now I just need to decide if I'm only going to replace clutch pulley or whole alternator.

 

[Old.Tony]

Glad you found it, it's not something I'd have thought of. Let's see if I can remember it when the next guy asks about a clicking alternator!

 

[flashum1]

Ordered new alternator from trump auto electrical on eBay, $275 shipped brand new with clutch pulley and 5 year warranty. Good deal I reckon! Especially when local auto sparky quoted $270 just to change pulley.