mick2444 Posted December 22, 2015 Share Posted December 22, 2015 hi, first post so xmas greetings every one. i fitted two 85 ah varta silver dynamic to a vw t4 autosleeper clubman 3 months ago after reading a&n recommendations.. one under bonnet and one under drivers seat 16mm square cable.. went to shell island end of oct 3 nights. used a 12v 16 inch tv and some led lights till early hours. before we set off back home the batterys where at 12.5 volts so not used much juice . two and half hour drive home checked the liesure batterys 12.68 v so they hadnt charged that much, they usually settle at 12.9 volts fully charged it had a 70 amp split charge relay and really thin wires for charging. so i read on here put bigger cables to a vsr relay to starter battery + to liesure battery + for quicker charging i did that today i checked charging volts before and after. before it was 14.4 starter battery 13 v liesure. i put 35mm square cable to 140 amp samlex vsr and batterys. the voltage is now 14.75 at both starter and liesure batterys 14.77 when i rev the engine. the batterys where fully charged before hand. is 14.75 volts too much and will it cook my batterys if i go for a drive ? i took the old spit charge relay out of the circuit. thanks mick Link to comment Share on other sites More sharing options...
Derek Uzzell Posted December 22, 2015 Share Posted December 22, 2015 Welcome to the Out&AboutLive forums, Mick. This link summarises split-charging methodology. http://www.12voltplanet.co.uk/split-charging.html My (limited) experience of charging systems that include a VSR is that, as long as the installation has been well carried out, it should be anticipated that the starter and leisure batteries will, in normal use, all be being charged at much the same voltage - which is what’s now happening with your vehicle. Received wisdom (according to GOOGLE!) is that a vehicle alternator should ideally be regulated to charge at between 13.8V and 14.2V, but a slightly higher voltage is quite commonly quoted. It might be useful to know the age of your T4 and which motor it has. I would have thought that a maximum voltage of 14.4V should be considered OK, but 14.77V does sound a high. (Are you certain that your voltmeter is accurate?) “Silver Dynamic” is a range of Varta starter batteries, so if it’s normal for the alternator of the VW T4 model on which your Clubman is based to output up to 14.77V, your leisure batteries should not be damaged. I think you need to be certain your voltmeter is accurate and confirm what is the maximum voltage your T4’s alternator should produce. You might also ask A&N Caravan Services about this as they are very familiar with the Varta batteries. Link to comment Share on other sites More sharing options...
mick2444 Posted December 22, 2015 Author Share Posted December 22, 2015 hi the van is a t4 2.4d with after market turbo year 2000 with a new last year 90 amp alternator. the volt meter is tested accurate on my car. i dont know if i should have got rid of all the old relay gubbins instead of just pulling the split charge relay out but i left the fridge relay there so it runs off the alternator which it still does thanks mick Link to comment Share on other sites More sharing options...
Derek Uzzell Posted December 22, 2015 Share Posted December 22, 2015 I guess you could try disconnecting the part of the system that is allowing charge to be provided to the leisure batteries, so that the alternator is just charging the starter battery. If the alternator were charging only the starter battery and was producing 14.77V, at least you’d then know that 14.77V is the alternator’s output without the extra complication of thr VSR. Link to comment Share on other sites More sharing options...
mick2444 Posted December 22, 2015 Author Share Posted December 22, 2015 hi, it was always 14.4 v at the starter battery before i fitted the vsr today i have just been out to check i wired it up right not much to it really . i just read 14.45 at both batterys at idle which is different to 3 hours ago at 14.75 . when i revd it went to 14.77 again Link to comment Share on other sites More sharing options...
mick2444 Posted December 22, 2015 Author Share Posted December 22, 2015 i have just been messing about again at 11 30 pm with my volt meter i think i have sussed it i start the van every thing looks good 14.2 idle 14.4 reved up . after aproximatly 4 to 5 minutes the idle speed jumps from 750 rpm to 950 rpm thats when the 14.77 voltage occurs. the van has always done this since i bought it 2 years ago , then when i set off driving the revs go back down to 750 rpm at the first junction when i stop 200 yards away dont know why that is ? so i think i will have to take it for a drive tomorrow make sure the volts drop back down thanks for the help. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted December 23, 2015 Share Posted December 23, 2015 The results of this GOOGLE-search https://www.google.co.uk/?gfe_rd=ssl&ei=MVJ6VsOYHtbEaLuHtcAO#q=vw+t4+14.5v http://www.justkampers.com/028-903-803-d-voltage-regulator-for-14v-bosch-alternator-vw-t4-1996-2003.html seem to suggest that 14.5V should be the maximum voltage produced by a 2000 VW T4’s alternator. As your inquiry is more applicable to the VW base-vehicle than to the Auto-Sleepers motorhome conversion, I think your best bet for feedback is likely to come from a VW forum. For example http://www.volkswagenforum.co.uk/forumdisplay.php?f=85 Link to comment Share on other sites More sharing options...
mick2444 Posted December 23, 2015 Author Share Posted December 23, 2015 went for a drive the vsr still charges at 14.7+ and the engine idles near a 1000 rpm instead of 800 rpm put the old relay in and disconnect vsr everything goes back to normal revs 800 charging volts 14.4 checked wiring again stumped now. Link to comment Share on other sites More sharing options...
Brian Kirby Posted December 23, 2015 Share Posted December 23, 2015 Don't know if this may help, especially the last paragraph, but it seems to be hinting that the problem may lie in the introduction of the VSR. http://tinyurl.com/pgoyvme Any good? Link to comment Share on other sites More sharing options...
mick2444 Posted December 23, 2015 Author Share Posted December 23, 2015 thanks brian, i have read the link you posted still cant work out why it ups the rpm and charges at 14.7+ volts it does this dead on 4 minutes from starting engine, before that every things ok theres no ecu on this van, it says its an intelligent relay gizmo as far as i can see it just makes or breaks a contact at preset level like the old 70 amp cube relay mick Link to comment Share on other sites More sharing options...
aandncaravan Posted December 23, 2015 Share Posted December 23, 2015 Hello Mick, top choice on batteries as they will tolerate a higher voltage rate, however they should not have to? I would expect a more normal 14.4v and sounds to me to be an issue with the D+ trigger somewhere potentially putting your Alternator at risk? The old system you had with the 70amp split charge relay, was presumably a conventional relay operated by the Alternator D+ wire like the Fridge operation now? If so what have you done to protect this D+ connector which, being no longer required, is presumably just loose? The old relay would have had 4 connections, the D+ trigger (usually a very thin wire as it is only around 2amps) the positive + from the Starter battery, an Earth - and a positive + to the Habitation battery. However, regardless of all that, please can we go back to the beginning as I wonder if you have moved from a good system to one less robust one? On your old system if the batteries were close to each other (rear of the bonnet area and front seat) you would not need very thick wires as the distances would have resulted in little voltage drop. The Charge rate is unlikely to have been more than 20amps, so (in theory) quite thin 2.5mm cable would have been sufficient for 20amps. In reality you need fatter than this, but 4.5mm would have given low voltage drop and around 40amps. So you would have gained little from upgrading the cable? The advantage of a VSR is simplicity of wiring as you don't need to run a D+ trigger from the Alternator (the circuit that puts out the Ignition Warning Light). It does not actually operate any better or give more charge like some think. A VSR has internal electronics that monitors the Starter battery voltage, and when this goes above around 13.4v it assumes the Alternator is charging, connects in the Habitation battery so this also gets charged by the Alternator It is just a switch that connects the two batteries together, exactly in the same way the old 70a relay connected the two batteries together when it detected the Alternator was spinning. When the Alternator stops spinning the Starter battery voltage drops so the VSR isolates the two batteries, in theory. A 140amp VSR is the current rating it is able to carry, not the charge it will give. Most 140Amp VSR's will still give the average 20amps of a conventional relay. The charge current is dictated by the Alternator/battery combination, not the relay or 'switch'. The VSR is simple to wire, but has some, potentially, unwanted side effects in that if you charge the Starter battery with a Car charger the VSR will 'see' the Starter battery voltage rise and connect in the habitation battery. This may be good, but if you are trying to get the starter battery quickly up to a point where you can start the engine, the VSR may have doubled the time it will take as you could now be charging two batteries. The VSR can also keep the habitation and Starter batteries connected longer than ideal, as some won't break the connection until the Starter battery has dropped below 13v. If you crank the Starter while the two batteries are connected together, both batteries will be called upon to power the starter, sometimes leading to a higher than ideal current passing through the VSR from the habitation battery to the starter. What I am try to say is, that the system you already had (assuming the 70a relay was operating correctly) was actually more robust and a better solution than a VSR as the minute the Alternator stops spinning the batteries are isolated. Varta Silver batteries don't go so well with a VSR as the greater efficiency can result in a higher initial resting voltage leading to the batteries being kept connected for longer than ideal. Depends on the VSR, but not unusual to see a Varta Silver sit after being charged with no load above 13v for some time. I suggest you go back to the original system (maybe replace the 70a relay for the same type?) but make sure all connections are perfectly clean. The fact that the Fridge system is still working, via a Alternator D+ trigger suggests that it is most likely to be sound? One other thing on battery charging from the Alternator : The Habitation battery charge rate of an Alternator is typically 10 - 15amps on a drive like yours from Shell Island? If the batteries dropped right down (and you did say batterieS, as in both, were low after the overnight on Shell Island) a trip of 2.5 hours at 10amps charge is only 25Ah into 2 batteries. That is just 12.5Ah per battery, so we would not expect the battery to get up much higher than the voltages you witnessed. So I am wondering if you are trying to address a problem that may not be there? If you go on our Solar Power page, we list a seller of a Power Meter (we don't sell them) that will not only tell you what volts and Amps you are using/charging at but also carries a tally of the total amp hours you take out/put in, say over a week? If you connect something like that in the Habitation Positive cable it will show power being drawn out and Power being put into the battery, etc. Easy to wire up. They are only about £16 but will help you diagnose if you have an issue and work out your usage?? Link to comment Share on other sites More sharing options...
mick2444 Posted December 24, 2015 Author Share Posted December 24, 2015 hi, thanks for the detailed explanation, i have probably been reading too much about thicker cables and bigger relays being quicker for charging these last few weeks and the silver dynamics have a resting charge rate over 12.90 v like you say so this conflicts with the vsr ? the van charges at a normal 14.4 v for 4 minutes then engine rpm goes up to about 950 rpm from 800 rpm dont understand why and charges at 14.7 v i put the old relay back in and disconnect vsr and all back to normal . i was thinking of getting the 100 amp albright contactor instead of the vsr that might have been a better choice about the same price. but from what you said i might be trying to fix a problem i havent got. i read everything you wrote about the varta batterys months ago and glad i bought them they dont seem to lose any charge after standing for weeks and discharge slowly in use plus the 5 year guarentee. but i was thinking of going off grid more often i have a honda eu2 generator but it takes up room in a small van and petrol can funnel etc i was looking for a cheaper soloution to a b2b charger which you dont advise on the vartas. just to complicate things further i was looking at my haynes manual tonight and it says my alternater should be charging at 14.5 to 14.6v so would that extra volt 14.7 be a problem ? i didnt do anything with the d wire i just left it connected to the old relay housing there are 3 cube relays the 70 amp scr one at the side of that i dont know what thats for ? then the fridge relay and 2 fuses i only removed the sc relay left everything else in place when fitting vsr thanks mick Link to comment Share on other sites More sharing options...
aandncaravan Posted December 24, 2015 Share Posted December 24, 2015 It is not so much the higher 0.1v output that is a worry but the fact that the Engines revs change. Just connecting the two batteries together should not alter the engine revs? Something potentially serious going on there? As the VSR gives no advantage in your situation, but does have several disadvantages (see more on this below) I would suggest that you stick with the original setup. But consider replacing the old relay with a newer one of the same type. The contacts can deteriorate over time leading to less charge reaching the Habitation battery. One other point I forget to mention was that a VSR has electronics permanently powered monitoring the voltage at the Starter battery. It is only a small power draw but over weeks can drain the Starter battery significantly. We would suggest that instead of trying to ramp up the charging side with the potential side effects that can give, that you look again at how you can reduce the power you use?. Rather than make the charging systems cope with your usage, adjust your usage to that of the charging systems?. If you really can't do that then look at a way of carrying your own portable EHU? If it was me I would ditch the Honda Eu20 as the noise is unsociable. They are much, much quieter than all the opposition, but still not nice to be next to. However, we do really rate the EU10i as that is whisper quiet, nothing in the Class comes close. The Hyundai and Chinese copies are at least 2 to three times as noisy, even though their labels say the opposite. If you fit the Honda Eu10i with a 'Rain Hood' it drops the noise still further and makes it less conspicuous. See our page on Generators (don't worry it's not a sales page as we don't sell them) : http://www.aandncaravanservices.co.uk/generators.php A quality Generator is a way of getting all the power you need without altering the Motorhome/Camper at all. Motorhomes used to be all about light, minimalist and efficient living. Using the minimum Water and power, that was the heritage? We had a Motorhome in some months ago for some Electrical work and when we cut the power, the Frost Protection valve dropped. I asked the owner to lock up the valve with a peg as the water was draining. He went into a panic like I have never seen. Turned out he had fitted additional Water tanks that held nearly 600 litres of Water so he could Wild Camp without the worry of topping up with Water. He got into a panic at the thought of losing it all. Everyone in the workshop thought he was a 'bit silly'. But then the next day we had in a Burstner with 4 batteries, a huge B2B and a 3000watt Inverter, etc. Link to comment Share on other sites More sharing options...
mick2444 Posted December 27, 2015 Author Share Posted December 27, 2015 hi, i put the wiring back to normal and everything ok i will take the generator in winter months thanks mick Link to comment Share on other sites More sharing options...
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