need4speed Posted May 19, 2015 Share Posted May 19, 2015 Starting to think about powering things up. Drafted a quick diagram. Now I'm anything but an expert at vehicle wiring so no need for the comments to be too damning.... That being said, please feel free to criticise. Especially if this can be made simpler or if it will set fire to my defender..... Batteries are Odessey PC1500's. Bus bars are 350A from mobilecentre. There is also an auxiliary fuse box and an Anderson socket for jump starting which is inside the vehicle on the seat box. Cable is all 40mm except the existing wiring to under seat fusebox and auxiliary fusebox. Quote Link to comment Share on other sites More sharing options...
Orgasmic Farmer Posted May 19, 2015 Share Posted May 19, 2015 Do you not want a relay between the 2 batteries to stop the starter battery being dragged down by the Aux? As wired you could just use a bigger single battery for same effect?? Quote Link to comment Share on other sites More sharing options...
easytiger Posted May 19, 2015 Share Posted May 19, 2015 I agree, you have no way of making sure that running ancillaries will not kill the starter battery Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted May 19, 2015 Share Posted May 19, 2015 I agree Phil, a 100 amp ignition switched relay and a fuse would protect the starter battery and allow winch use. Mo Quote Link to comment Share on other sites More sharing options...
need4speed Posted May 19, 2015 Author Share Posted May 19, 2015 Thanks chaps. Will this work better? 2nd draft.. Quote Link to comment Share on other sites More sharing options...
western Posted May 19, 2015 Share Posted May 19, 2015 the 2 battery earth negative terminals are joined together on my LR split charge system. Quote Link to comment Share on other sites More sharing options...
need4speed Posted May 19, 2015 Author Share Posted May 19, 2015 Yes I suppose I've wasted a space on my negative bus bar. Just need to join both neg battery terminals together... Cheers Ralph Quote Link to comment Share on other sites More sharing options...
zardos Posted May 19, 2015 Share Posted May 19, 2015 Do you not want a relay between the 2 batteries to stop the starter battery being dragged down by the Aux? As wired you could just use a bigger single battery for same effect?? It depends on your goal, more power for things like winches or to stop things like fridges from flattening your start battery. The goal was not stated. The first wiring diagram was good for the goal of more power for winches. The second diagram looks wrong, as the aux battery has no function (in a normal split charge system the aux battery would have it's own fuse box for the fridge and other things you want to run when the engine is not running) Think of the following scenarios 1. Engine running, alternator is producing 14.4v (not sure why the x-charge is wired to the alternator when it could be wired to the + busbar as this would also see 14.4v from alternator, but it makes no difference) The x-charge would connect the aux battery to main battery to charge (so all good) 2. Engine not running alternator is not producing 14.4v so the volt at the alternator + terminal will be at 12V so the x-charge as a voltage sensitive relay would not connect the aux battery, it would be isolated with nothing connected) The only fusebox shown is connected to the main battery therefore any load would flatten that. After drawing so much load for things like fridges and stuff, the main battery could not have enough charge to start the engine and thus turn the alternator to generate enough voltage to connect the fully charged aux battery. Stating which of the 2 goals you want would help draw a correct diagram. Quote Link to comment Share on other sites More sharing options...
need4speed Posted May 20, 2015 Author Share Posted May 20, 2015 Thanks for the reply Zardos. To answer your question re the wiring of x-charge to alternator. The reason behind this was purely due to following the official x-charge fitting instructions.. http://foundry4x4.co.uk/pdf/X%20Eng%20at%20Foundry%204x4%20X-Charge%20Instructions.pdf In response to your other points, my vehicle is a big gas guzzling v8 so unlikely to be venturing too far. The only thing I can foresee me running without the engine running might be a fridge one day. Most of the extra equipment it will have will be needed while engine running. For example winch, compressor, air-lockers, and extra lights. Quote Link to comment Share on other sites More sharing options...
easytiger Posted May 20, 2015 Share Posted May 20, 2015 If you wire it up as you have suggested but put a feed to an aux fuse box from second batt you can take the feed for things like aux lights from this fuse box then if you do ever need to run these with the engine switched off there is no danger of killing the starter batt. Same applies for things like 12v power sockets and audio / entertainment. This stuff will still get the 14.4 volts from the alternator while the engine is running (provided the starter battery is charged). Quote Link to comment Share on other sites More sharing options...
need4speed Posted May 20, 2015 Author Share Posted May 20, 2015 Thanks for all the comments chaps. Big thanks to PaulMc as well for helpful PM's Would it affect the operation of the x-charge at all if I were to connect 1 end of it to positive bus-bar rather than directly to main battery terminal? Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted May 20, 2015 Share Posted May 20, 2015 You can connect your left-hand wire that goes to the positive battery terminal in your diagram currently, to the bus bar, with zero effect Quote Link to comment Share on other sites More sharing options...
need4speed Posted May 20, 2015 Author Share Posted May 20, 2015 You can connect your left-hand wire that goes to the positive battery terminal in your diagram currently, to the bus bar, with zero effect Good. I don't mind the bus bars being busy (they have 4 x 10mm terminals) but my OCD kicks off when I see cluttered battery terminals. I start to come out in cold sweats and need to contact GP for sleep meds...... Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted May 20, 2015 Share Posted May 20, 2015 You know you can get batteries with integrated, separate bolt-on terminals https://www.tayna.co.uk/Enduroline-CXV-X-1000-Amp-P9008.html Multi-ring terminals FTW Quote Link to comment Share on other sites More sharing options...
Ex Member Posted May 20, 2015 Share Posted May 20, 2015 You really need a dedicated wire from the battery to the starter solenoid and a dedicate ground wire from the battery to the gearbox or engine. Running through terminal blocks is just going to cause a world of trouble starting in the future. If you are running two batteries and want them to do different tasks, then you need two separate 12V positive circuits. If you just want to run them in parallel, don't waste your time and get a single larger battery. Quote Link to comment Share on other sites More sharing options...
need4speed Posted May 20, 2015 Author Share Posted May 20, 2015 To be honest they aren't your standard weedy little terminal blocks. They can take a continuous 350A and a hell of a lot more than that for short periods... Quote Link to comment Share on other sites More sharing options...
zardos Posted May 20, 2015 Share Posted May 20, 2015 Thanks for the reply Zardos. To answer your question re the wiring of x-charge to alternator. The reason behind this was purely due to following the official x-charge fitting instructions.. http://foundry4x4.co.uk/pdf/X%20Eng%20at%20Foundry%204x4%20X-Charge%20Instructions.pdf In response to your other points, my vehicle is a big gas guzzling v8 so unlikely to be venturing too far. The only thing I can foresee me running without the engine running might be a fridge one day. Most of the extra equipment it will have will be needed while engine running. For example winch, compressor, air-lockers, and extra lights. So given you stated goal I would go with Wiring diagram 1 (no x-charge relay, just parallel batteries for more power). If you do want to future proof it now (instead of changing it when you add a fridge), you can do diagram 2 with x-charge but put a manual high current bypass cable between the 2 battery positives with a isolator switch (250A), so they can be joined without going through the lower capacity X-xharge which might also disconnect when the system is under high load) It is probably also wise to put the extra lights via the Aux FuseBoard off the Aux Battery as this is something you might want to run without engine running. Example diagram below When winching use the manual isolator to join the batteries Quote Link to comment Share on other sites More sharing options...
Ex Member Posted May 20, 2015 Share Posted May 20, 2015 To be honest they aren't your standard weedy little terminal blocks. They can take a continuous 350A and a hell of a lot more than that for short periods... That is not the point. You want to minimize terminal connections with the high amperage loads. Quote Link to comment Share on other sites More sharing options...
need4speed Posted May 21, 2015 Author Share Posted May 21, 2015 Just have to share what a friend of mine sent me as it makes me smile every time I see it... Says it all really. Quote Link to comment Share on other sites More sharing options...
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