bobtailrangie Posted July 12, 2010 Share Posted July 12, 2010 Hi everyone Whats the largest single v alternator i could get hold of for sensible money from another car? Or what multi v alternators can take a single v pulley? Im doing a twin alternator setup + id like 2 150amp alternators for winch etc Cheers James Quote Link to comment Share on other sites More sharing options...
Aragorn Posted July 12, 2010 Share Posted July 12, 2010 I've changed pulleys on a bosch poly-vee alternator before, just need to mess around with shims and washers etc to get it all to sit in the right position. I'd wonder about the ability of a V-belt to provide the amount of power you require though. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted July 12, 2010 Share Posted July 12, 2010 I seem to remenber someone (possibly Simonr) saying that a single v-belt would support up to around 100A alternator, otherwise you need multi-V. One question, why the need for 300A charging capacity? You don't need 300A charging capacity just to run a winch which may once in a blue moon take 300A. Quote Link to comment Share on other sites More sharing options...
simonr Posted July 12, 2010 Share Posted July 12, 2010 You can deliver about 5Hp through a single V and 30Hp through a 5V PolyVee. Any more than that and they try to catch fire! (how do I know this?) Assuming no mechanical or electrical loss, 5Hp = 3.25kw which is about 250A. However, to give you something reliable that will not eat belts, slip under high load or get too hot, 100A is the practical limit for single V and 600A for polyvee. Si Quote Link to comment Share on other sites More sharing options...
jad Posted July 12, 2010 Share Posted July 12, 2010 there is a guy in my club running a 130 Amp alternator from a V belt and i think he ahs ripped though a couple of belts so far....... Quote Link to comment Share on other sites More sharing options...
zim Posted July 12, 2010 Share Posted July 12, 2010 I've run single V belts on 200a alternators (20v). 2 of these alts on a little 1.6 engine as well as a 60a 12v G Quote Link to comment Share on other sites More sharing options...
Orgasmic Farmer Posted July 12, 2010 Share Posted July 12, 2010 I run a 120 amp alternator piggy-backed off my aircon pump pulley (200tdi). I gave £16 for the alternator from a renault laguna and although it came with a multi V I was able to cobble a v pulley to fit. However, the only pulley I had giving a good ratio needed a small bit of machining on a lathe to get it to fit in the right place. Have yet to damage the belt after several years of hard use on a challenge truck. Quote Link to comment Share on other sites More sharing options...
Orgasmic Farmer Posted July 12, 2010 Share Posted July 12, 2010 Quote Link to comment Share on other sites More sharing options...
Adam001 Posted July 12, 2010 Share Posted July 12, 2010 there is a guy in my club running a 130 Amp alternator from a V belt and i think he ahs ripped though a couple of belts so far....... That could/would be me! lol I have a 100 amp (130amp on the power curve) alternator on a V belt and have shredded 3 belts so far. Although I am now using a allmakes belt and have fabricated a tensioner and it seems to be holding and under load it isn't heating up for now. I wouldn't recommend running a big alternator in the standard position on a 200tdi though (unsure on defender 200tdi, mine is disco). I have 3 spare belts just in case haha. Although unfortunately there is no ideal kit to relocate and use the larger aircon belt, especially on the discovery 200tdi engine where the coolant pipe is in the way. I have been speaking to Gwyn Lewis and if my current set-up fails again I'll relocate it. Quote Link to comment Share on other sites More sharing options...
western Posted July 12, 2010 Share Posted July 12, 2010 I run a 100amp alt driven by a single Vee belt, no problem with it eating belts in about 12 years. Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted July 12, 2010 Share Posted July 12, 2010 Forget pure amps Mondeo one that I have on the V8 does wonders as it shoves out something like (from memory ) 50amps at just above tickover and 120 amps full chat The high output low rpm is very attractive forn charge at tickover etc ? Had to convert to to a V belt, do a search I did a thread on it Lastly there are differing Vs in V belts, make sure the pulley and belt are matched or it will shread at worse and / or stink a burning smell ask me how I know this Nige Quote Link to comment Share on other sites More sharing options...
simonr Posted July 12, 2010 Share Posted July 12, 2010 I'm not necessarily saying that a 100A alternator WILL shred belts - just that you are getting into territory where it's more likely and the other factors have a bigger influence. The load it presents is obviously determined by the amount of current you are drawing from it - so the belt shredding may be as much the application as the alternator itself. Other things that make a difference are the amount of wrap of the belt round the pulley and the belt tension. Si Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted July 13, 2010 Share Posted July 13, 2010 .......aside form all that, why the 300A charging circuit? Quote Link to comment Share on other sites More sharing options...
zardos Posted July 13, 2010 Share Posted July 13, 2010 .......aside form all that, why the 300A charging circuit? Alternator mostly don't charge batteries but supply power to run electrical items. So more alternator output means you can run more stuff without voltage drop or draining the battery. This is why as vehicles have got more electrical toys (heated seats, electric windows, etc) the ratings of alternators go up. Also the max charge current of a battery is normally between 20-40Amps but if you have 3 batteries like me then you might be getting close to 100Amps charge rate in total. As for the largest alternator on a v belt, I'm sure that vehicle manufacturer did the research and I think that most standard Landrovers with 100+ Amp alternators use Poly Vee (My 3.9 non serpentine Engine has V for everything else but a Poly Vee for the 100 Amp Alternator. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted July 13, 2010 Share Posted July 13, 2010 100A charging circuit for 3 batteries, yes I can see that, but 300A? Being an electrical engineer I understand these things a little, I still think 300A is WAY overkill. I was asking the OP what their reasoning was, if it was 'well the winch can take 300A and I don't want a flat battery' the answer would be very different, rather than leading them to a very expensive (2 alts, 2 batts and extraneous mounting bracketry, not to mention cabling) and completely unnecessary 'solution'. Quote Link to comment Share on other sites More sharing options...
zardos Posted July 13, 2010 Share Posted July 13, 2010 100A charging circuit for 3 batteries, yes I can see that, but 300A? Being an electrical engineer I understand these things a little, I still think 300A is WAY overkill. I was asking the OP what their reasoning was, if it was 'well the winch can take 300A and I don't want a flat battery' the answer would be very different, rather than leading them to a very expensive (2 alts, 2 batts and extraneous mounting bracketry, not to mention cabling) and completely unnecessary 'solution'. The original post did say it was for a winch and some for some winches the theoretical max load would be 1000A (then you can times that by 2 for front and rear winches and yes I have used both at once) Quote Link to comment Share on other sites More sharing options...
Adam001 Posted July 13, 2010 Share Posted July 13, 2010 What winch uses 1000amps???! are you talking some twin motor affair? Quote Link to comment Share on other sites More sharing options...
bobtailrangie Posted July 13, 2010 Author Share Posted July 13, 2010 Cheers for all the replies 300 is alot I think 1 alternator at 80-100 would be ok for starting battery, 4 electric fans + all the usual bits Id like a big alternator for the other battery as its for winching, will have a rear winch soon so there will then be a 3rd battery Is there a way i can have just a poly v belt for winch alternator + v belts for the rest? cheers for all the help + advise James Quote Link to comment Share on other sites More sharing options...
zim Posted July 14, 2010 Share Posted July 14, 2010 this is from a stereo competition car i built this was used for charging 12 x 8v batteries. when i changed my system to 24 x 8v batteries, i stopped using the alternators and used a 240v mains charger, charged at 21v float at 18.5, but could be dropped to 18v (which is the upper limit allowed) by using a lightbuld. with this system i could draw up to 3,000A for a few seconds. Battery voltage dropping from 18.0 to about 12 - 13. G Quote Link to comment Share on other sites More sharing options...
Superpants Posted July 14, 2010 Share Posted July 14, 2010 It is also worth bearing in mind that the front end drive on the engine will be designed to deliver a maximum power. Increasing the power (by addition of bigger alternators, hydraulic pumps, aircon etc) results in increased side loads on the main crank pulley, which can in turn have detrimental effects on the life of the bearing and seals. Not sure what the deisgn load on the land rover engines are, but I know the VW 1.9 and 2.4TDI engines aren't warranted for more than a 10kW power draw from the FEAD. I'd therefore be careful about how big a load I'd hang off the front of the engine. HTH Mike Quote Link to comment Share on other sites More sharing options...
Adam001 Posted July 14, 2010 Share Posted July 14, 2010 Good point that! ^^ Quote Link to comment Share on other sites More sharing options...
zardos Posted July 14, 2010 Share Posted July 14, 2010 What winch uses 1000amps???! are you talking some twin motor affair? Warn quote 480Amps for a 9500lbs pull from an xp motor, so for a twin motor it could reach twice that but would probably not be at twice the load due to different gearing. Quote Link to comment Share on other sites More sharing options...
pete3000 Posted July 15, 2010 Share Posted July 15, 2010 one of these alternators should sort you out http://www.machinemart.co.uk/shop/product/details/6kva-3000rpm-alternator-1-phase/path/alternators just add a large step down transformer to 14/28 volts a pulley and voila I suspect that wasn't really the question you were asking though? Quote Link to comment Share on other sites More sharing options...
jbs Posted July 16, 2010 Share Posted July 16, 2010 I'm sure I saw something-perhaps on here about using a Vito van alternator it give's out something silly like 200 amp's anyone know if this is true? John Quote Link to comment Share on other sites More sharing options...
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