rtbarton Posted September 10, 2005 Share Posted September 10, 2005 If you want a dead basic setup I do this http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...AMESE%3AIT&rd=1 Link to comment Share on other sites More sharing options...
SteveG Posted September 10, 2005 Share Posted September 10, 2005 Hi Si Theyare made by BEP Marine, in NewZealand. In NZ the cluster costs about $145, so probably about 150 pounds here as usual for 50 or 90 Amp versions. The 300A VSR on it's own is $155, so a heavy duty cluster would be about $250 you can view some prices here..www.discount-marine.co.nz BEP website is.. BEP Marine Distributors in UK are: United Kingdom EC Smith & Sons Ltd. C.C Unit H & J kingsway Est. Luton, Beds,LU1 1LP, England Phone +44 15 8272 9721 Fax +44 15 8272 3460 enquiries@ecsmith.com United Kingdom Merlin Equipment Ltd Unit 4, Cabot Business Village Holyrood Close Cabot Lane, Poole Dorset, BH17 7BA England Phone +44 (0) 1202 697979 Fax +44 (0) 1202 691919 www.merlinequipment.com sales@merlinequipment.com Cheers Steve Link to comment Share on other sites More sharing options...
Mr Scrapiron Posted September 10, 2005 Share Posted September 10, 2005 I can get a Defender VSS from a scrapyard and spray it red - it'll cost though Link to comment Share on other sites More sharing options...
Neil Marshall Posted September 10, 2005 Share Posted September 10, 2005 They look good NeilAny idea of cost and supplier? Si Email me and will forward full price list - for example a 70 amp VSR is £54, a 140 amp £98 Neil neil.marshall@btinternet.com Link to comment Share on other sites More sharing options...
simonr Posted September 10, 2005 Share Posted September 10, 2005 Neil, Thanks for the lead. Although they look nice, they are a bit too expensive (even for me!). A LR VSS seems a lot better value - better still from a scrap yard! Si Link to comment Share on other sites More sharing options...
jwriyadh Posted September 10, 2005 Share Posted September 10, 2005 Simonr, take the time to watch what happens when you bump start a car with a flat battery. Your clamp-meter will show that the alternator goes onto its full output and does charge the battery……for about 2-3 minutes. Then the battery terminal voltage begins to rise (irrespective of its level of charge) causing the alternator current output to reduce to a much lower level. The charging process then continues at a reduced rate. Contrast that with the situation where the battery has a winch under load across it. The winch load pulls down the battery voltage…. and the alternator output voltage thus causing the alternator regulator to go to full output. This situation will last as long as you continue to winch. My reason for commenting here is nothing to do with Winch Challenges or the like, the competitors have learnt what works the hard way and have built their systems in the full knowledge of the pitfalls. However, it is prudent to warn the average non-competitive winch user that slapping a winch on his series motor will probably cause gradual degradation of his alternator and the associated wiring. As for spending vast sums on a split charge system, I am even more careful than most Yorkshire folk. The Defender and Discovery both have a simple relay operated by the alternator field diodes which is reinforced by a continuously rated solenoid to allow winching with the engine running if required. The Ltwt had a 70 amp relay from a Ford Siera, as its 17ACR was on its last legs winching was done with engine dead. The comment on VSS looks useful, thanks. Moglite, if your main concern is the availability of power to start the engine then the ideal way is to use a diode blocker.There will be a voltage drop across it but that will only extend the time required for the batteries to recieve a full charge. jw Link to comment Share on other sites More sharing options...
rtbarton Posted September 10, 2005 Share Posted September 10, 2005 You should use a battery sensed alternator with blocking diodes. Most alternators are machine sensed, ie they measure the output voltage internally and regulate to that. Battery sensed have an extra thin wire connected between the alternator and the battery +ve terminal, thus the regulator senses the actual battery voltage, compensating for voltage drop due to wires and diodes. Link to comment Share on other sites More sharing options...
Neil Marshall Posted September 10, 2005 Share Posted September 10, 2005 This is a complex subject, isn't it! Strangely, people will spend £500-1,000 on a winch, £ 300 on a pair of yellow tops, £150 on a plasma line, £50 on fairleads, then hooks, cables etc on top......but get concerned about the cost of a good battery management system. Are we getting our priorities right? Let me also pose a slightly different question....who makes the perfect split charge system and why is it the best? And can it be replicated more cheaply than buying? And - if yes - is anyone prepared to make em up? Neil Link to comment Share on other sites More sharing options...
jwriyadh Posted September 10, 2005 Share Posted September 10, 2005 Before you pose your question you need to define what you want the split charge system to accomplish. There are as many variations in requirements as there are variations in solution. You may choose between the following list of properties and add more if desired; Primary battery protection Low cost Automated Manual overide Low auxilliary load High auxilliary load Can fix with a hammer Complexity Reliability Compatability with all alternators Looks bling Discrete and so on, Then you need to add in the proposed way it will be used, another vast variety. At the moment Simonr's device has a lot going for it, but would it suit your own personal requirements? jw Link to comment Share on other sites More sharing options...
jwriyadh Posted September 10, 2005 Share Posted September 10, 2005 Double post!!! Deleted. jw Link to comment Share on other sites More sharing options...
Mo Murphy Posted September 10, 2005 Author Share Posted September 10, 2005 Crumbs, this threads a bit deep for me ! I'll buy one of Simon's methinks Mo Link to comment Share on other sites More sharing options...
western Posted September 10, 2005 Share Posted September 10, 2005 One for the Tech Archive I think Link to comment Share on other sites More sharing options...
simonr Posted September 10, 2005 Share Posted September 10, 2005 I guess, a relay with a diode to preserve the primary battery would meet most of those requirements. The cheapest 100A diode from RS is over £30 - and needs a heatsink. A second relay to bypass the diode controlled by a switch (with a blue LED for bling) would meet the manual bypass and bling requirement. In this case it might be better to replace the diode with a bank of MOSFETS. (A MOSFET behaves like a switch with a diode across the terminals. It will conduct one way, but only in the other direction if the switch is closed) Then you might as well replace the other relay with a few more MOSFETS. Add High Side drivers to drive the MOSFETS and a current mirror to protect the MOSFETS against over-current. It would have to be well sealed and would need a good degree of decoupling to protect the MOSFETS from transient spikes. The bypass MOSFETS will have to handle say 200A for starting and the others say 100A so it's going to need about 15 MOSFETS and a fairly chunky heatsink. Suddenly you have something costing over £100 just to build. You might as well add in a managed charge profile chip - just to get the max out of the batteries. If you add voltage monitoring on both batteries, reverse polarity protection, short circuit protection and a thermal cut-out in order to make it bullet proof, I reckon you'd struggle to retail it for less than £200. It makes you realise why a simple relay, for all it's shortcomings, is not such a bad option! Si PS. In a past life, I had a little too much experience of designing & building 1000A DC Motor speed controllers. The requirements on the MOSFET switching are not all that different. I have thought about building a speed control for a winch - but controlling series wound motors is a complete sod! Link to comment Share on other sites More sharing options...
GBMUD Posted September 10, 2005 Share Posted September 10, 2005 [simlpleton]If flatening the service battery is undesirable and over stressing the alternator regulator is likely to cause un-timely failiour, would it not make sense to rig the split charge in such a way as the relay circuit is broken whenever the winch is engaged? That way, the winch battery will be isolated from the rest of the system while winching and automaticaly go back on charge when the winch motor stops. IIRC there is one terminal on the winch motor that is live whether winching in OR out? Use that to control a second, small relay on the low current side of the split charge relay. Or have I misunderstood? This way, the alternator never charges the winch battery while the voltage is low and the service battery never gives it's charge to the winch - well, perhaps for a fraction of a second perhaps, before the split charge relay de-energises.[/simpleton] Please don't flame me if I am wrong. Chris Link to comment Share on other sites More sharing options...
rtbarton Posted September 10, 2005 Share Posted September 10, 2005 Chris.. I was thinking on those lines. You could drop the relay when the winch starts easily by earthing the relay through the winch motor. Maybe as well to have a small diode in series with the relay coil to stop the winch voltage feeding back into the charging circuit though. If you use big blocking diodes instead of a relay don't forget you need a pair, the two anodes connected together and to the alternator and the cathode of each conncted to one battery. Otherwise you will still feed the aux. battery from the main battery when the engine is stopped. Link to comment Share on other sites More sharing options...
rtbarton Posted September 10, 2005 Share Posted September 10, 2005 Let me also pose a slightly different question....who makes the perfect split charge system and why is it the best?And can it be replicated more cheaply than buying? And - if yes - is anyone prepared to make em up? Neil There's no such thing as the best system - only the best (ie most appropiate) for a particular job. I think the one I sell is the best because I make a profit on it Link to comment Share on other sites More sharing options...
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