boy Posted October 16, 2009 Share Posted October 16, 2009 hello all i've been thinking about fitting a 2nd alternator to my defender is it worth it!! if so can anyone help in giving ideas in how to doing it!! Quote Link to comment Share on other sites More sharing options...
berti1554 Posted October 16, 2009 Share Posted October 16, 2009 Makes no sense to me. If the one that is installed hasn't enough capacity install an alterantor that has higher capacity. That's what I did on my Series III. Quote Link to comment Share on other sites More sharing options...
m&mv80 Posted October 16, 2009 Share Posted October 16, 2009 depends why you want to fit it, if your fitting a second battery for winching or for something with a heavy load/discharge rate i would say yes its worth it, if not then just a split charge system would be fine if your not fitting a second battery then why do you want two alternators?? Quote Link to comment Share on other sites More sharing options...
zardos Posted October 16, 2009 Share Posted October 16, 2009 There are two method of using 2 alternators 1. Each alternator charging independent battery banks. What you use each battery bank for depend on what you are trying to power. The only example I've seen is one bank to run the car and one bank to run all the winches. But I'm sure that you could use this instead of a split charge system to run things like fridge and other leisure type high demand electric items. Pro's Cheaper, as you could use just a standard alternator, though some people use a alternator with a separate earth. Con's You need 2 batteries (but people wanting more power usually already have multiple batteries) You need to carefully plan the loads on each bank to get any real benefit out of it. e.g. If one banks is running the car, all it has to support are intermittent high loads , like lights, windscreen wipers, electric fans? heater blower? and constant low loads fuel pump? Stop solenoid?, etc The other bank is running the winches. If you draw a lot of current using the winches then the only benefit is the winch alternator does not have to support the other load, which could be as little as running the stop solenoid or fuel pump + coil. The other load is usually no way near the maximum alternator output, usually the car alternator is designed to supply more than the maximum electric load (excluding the starter motor). Thus there is a lot of wasted current generating capacity. 2. Two Alternators charging the same battery bank. Pro's Maximum current generating capacity always available to all loads It actually only requires 1 battery. Redundancy, if one alternator stops working the other will continue to supply current to all loads (the only problem is that a common alternator failure is the bearing seizing, so that depends on you drive belt setup, do they have independent drive belts? My V8 does, so the alternator bearing seizing meant that I could carry on the event on battery power alone, the water pump and power steering continued to work). Con's You need a special separate alternator controller otherwise the alternator voltage sensing circuits will fight each other on which alternator is supplying the power. These cost a couple of hundred quid. You could flatten the one battery bank enough with a very high load like a winch, which would mean you have a problem restarting if you stall. If I needed more power generating capacity I would go for option 2. Quote Link to comment Share on other sites More sharing options...
boy Posted October 18, 2009 Author Share Posted October 18, 2009 thanks for all the info people !! i looking into running to winches so one alternator will be for the running things and the other will be just for the winches!! dose anyone know how hard or easy it is to fit the 2nd alternator!! dave Quote Link to comment Share on other sites More sharing options...
western Posted October 18, 2009 Share Posted October 18, 2009 have a read of this meant for a 200tdi, but fitting to a 300tdi could be done http://forums.lr4x4.com/index.php?showtopic=1023 Quote Link to comment Share on other sites More sharing options...
reb78 Posted October 18, 2009 Share Posted October 18, 2009 If you have two alternators running two batteries, dont you require a seperate earth for at least one of them to keep it completely isolated from the other one? Quote Link to comment Share on other sites More sharing options...
zardos Posted October 18, 2009 Share Posted October 18, 2009 If you have two alternators running two batteries, don't you require a separate earth for at least one of them to keep it completely isolated from the other one? No, is the answer. Any attempt to make them totally isolated will fail when using it for winches, as the winch motor earth is their metal bodies which are usually bolted to the metal of the car via the winch body (which is the other earth) Quote Link to comment Share on other sites More sharing options...
Jurriaan Posted October 19, 2009 Share Posted October 19, 2009 have a read of this meant for a 200tdi, but fitting to a 300tdi could be done http://forums.lr4x4.com/index.php?showtopic=1023 Yes, just use the spot where the air con compressor sits. You can adapt an air conditioning mount. Militairy 12V & 24V vehicles should have a second alternator, you might be able to use that mount? Here on my dads 2.8TGV: Quote Link to comment Share on other sites More sharing options...
JST Posted October 19, 2009 Share Posted October 19, 2009 as the winch motor earth is their metal bodies which are usually bolted to the metal of the car via the winch body (which is the other earth) i thought it was usual practice to run the winch motor earth back to the the bat terminal? Quote Link to comment Share on other sites More sharing options...
boy Posted October 19, 2009 Author Share Posted October 19, 2009 hello all thanks for all the info helps out a lot!! has any got any pics of one on a 200tdi disco engine!! just to give me sum ideas!! dave Quote Link to comment Share on other sites More sharing options...
zardos Posted October 19, 2009 Share Posted October 19, 2009 i thought it was usual practice to run the winch motor earth back to the the bat terminal? Yes to supply an additional better earth, so as not burn out the weedy standard battery to chassis one. But the additional earth does mean the winch is isolated from the chassis. Quote Link to comment Share on other sites More sharing options...
white90 Posted October 20, 2009 Share Posted October 20, 2009 Not unless you insulate it the mountings the bumper mountings/bolts etc will at connect the winch to the chassis quite well. Quote Link to comment Share on other sites More sharing options...
zim Posted October 20, 2009 Share Posted October 20, 2009 Yes to supply an additional better earth, so as not burn out the weedy standard battery to chassis one. But the additional earth does mean the winch is isolated from the chassis. sorry, but you're wrong. as above. if your vehicle is negative earth (i.e. landrovers) then your battery negative is connected to your chassis. which in turn means your winch casing is also 'earth'. i suppose you could get round it, if the winch was fitted with non conducting materials. G Quote Link to comment Share on other sites More sharing options...
reb78 Posted October 20, 2009 Share Posted October 20, 2009 Yes to supply an additional better earth, so as not burn out the weedy standard battery to chassis one. But the additional earth does mean the winch is isolated from the chassis. I've got a feeling he meant to type doesn't but forgot the 'n't'!! Quote Link to comment Share on other sites More sharing options...
Orgasmic Farmer Posted October 20, 2009 Share Posted October 20, 2009 hello all thanks for all the info helps out a lot!! has any got any pics of one on a 200tdi disco engine!! just to give me sum ideas!! dave I simply piggy backed a 120 amp one off a Renault (Ebay for £16) ontot the Aircon pump. Getting a suitable sized v-pulley to fit (to replace the multi v pulley) was a faff and involved a small amount of machining but there is probably something out there that is a straight fit if you look long and hard enough. If you have no aircon (mine is used for on-board air) then you can simply mount it in place of the compressor but you wil then need to source the tensioner pulley (hens teeth!). I have a total of 240 amps of charging power going into 2 large tractor batteries and have never had an issue with power when winching. No complex electronics, just a separate indicator for each alternator in the dash. Quote Link to comment Share on other sites More sharing options...
JST Posted October 20, 2009 Share Posted October 20, 2009 I have a total of 240 amps of charging power going into 2 large tractor batteries and have never had an issue with power when winching. thats cos it goes out less than mine!!! i have a similar alt setup as Pikey 2 alts, no complex electircs just two wng lights on the dash, they feed two tractor batteries, one 85 A and one 90A alt Quote Link to comment Share on other sites More sharing options...
white90 Posted October 20, 2009 Share Posted October 20, 2009 What abot the wiring James? any pics of the install? Quote Link to comment Share on other sites More sharing options...
JST Posted October 20, 2009 Share Posted October 20, 2009 wiring i picked up off Innovate on how to do it - used a spare bulb on the dash - engine management IIRC. dont have any pics to hand and dont wasnt to take any at the moment as the mount failed on the De-Cider and it was rewelded on Sat night after the night stages and doesnt look the best. its in the same place as the comp would go with a single 4groove belt of the top pulley tensioned off an arm on alt bracket to the alt. Quote Link to comment Share on other sites More sharing options...
zardos Posted October 20, 2009 Share Posted October 20, 2009 Yes to supply an additional better earth, so as not burn out the weedy standard battery to chassis one. But the additional earth does mean the winch is isolated from the chassis. sorry, but you're wrong. as above. if your vehicle is negative earth (i.e. landrovers) then your battery negative is connected to your chassis. which in turn means your winch casing is also 'earth'. i suppose you could get round it, if the winch was fitted with non conducting materials. G You are right, my two sentences are opposite to each other in meaning, that's because I missed a word out on the second sentence. I meant to say:- But the additional earth does not mean the winch is isolated from the chassis. This now aligns up with my early post that prompted the question about the additional not separate earth. Quote Link to comment Share on other sites More sharing options...
zardos Posted October 20, 2009 Share Posted October 20, 2009 I've got a feeling he meant to type doesn't but forgot the 'n't'!! You hit the nail on the head. Note to self, must spend more time proof reading posts :-) Quote Link to comment Share on other sites More sharing options...
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