Tracker Posted March 30, 2015 Share Posted March 30, 2015 Where we park at home does not get enough sunlight on the PV panel to keep the batteries charged in the winter, which was it's principle purpose, so when we change the van I am contemplating doing without it. For those who stay put off grid for several days I can see that a decent solar panel is a godsend but as we rarely stay anywhere more than two nights I am starting to think that a Stirling 50 amp battery to battery charger coupled with a 2nd leisure battery would make do the job better especially for those frequent times that we only move a few miles at a time. To conserve battery power when not in use I will probably isolate the leisure batteries and I am considering doing the same for the engine battery? HOWEVER, I notice that sometimes folk have problems when a disconnected cab battery is re-connected so maybe a battery isolator on the engine battery is not such a good idea as I really can do without avoidable issues. Any thoughts anyone please? Link to comment Share on other sites More sharing options...
urbanracer Posted March 30, 2015 Share Posted March 30, 2015 I have a 2012 Boxer twice the starter battery has been removed and no problems even the radio worked without the need to reset the code. The only item that needed setting was the clock. Link to comment Share on other sites More sharing options...
Keithl Posted March 30, 2015 Share Posted March 30, 2015 Rich, You don't say in your OP but are you able to plug your MH in to 230 volts at home? If so use one of the smaller CTEK chargers which are safe to leave connected all the time or just plug in for 24 hours once a week or so. If our MH doesn't move for over 4 weeks (very rare I hasten to add) then I charge each battery for 24 hours. I have a small socket wired directly to the leisure battery (through a fuse) and the cab cigar lighter socket is permanently live so I can charge either from inside the MH. Keith. Link to comment Share on other sites More sharing options...
kevina Posted March 30, 2015 Share Posted March 30, 2015 Also consider the Votronic b2b charger, I bought mine from http://www.wohnkabinen-shop.de/de/Elektronik/Ladetechnik/Votronic-Lade-Booster-VCC-1212-45-IU a couple of years ago and it has given great performance. With the current exchange rate it might now be even cheaper than the Sterling unit. Kev Link to comment Share on other sites More sharing options...
Tracker Posted March 30, 2015 Author Share Posted March 30, 2015 Just spoke to our local independent Peugeot garage and they said that usually you can disconnect a Boxer battery and have no issues at all when you reconnect but sometimes you can have issues with window, central locking etc and they do not know why?? Franco / Italian electrics maybe ?? Keith - Thanks for the help. I don't currently plug the van in to mains but I could fix an outdoor socket close to it and use my Ctek charger. The again I suppose I could use the inbuilt charger for that purpose and it might even charge both batteries if I am lucky? Can't say I am enthusiastic about leaving any battery charger on all the time but it would be simple enough to nip out and give it a blast every couple of weeks if it is not in use. Our cab cigar lighter sockets are only live with the ignition on. so might have to consider a small 4 amp B"B to run from leisure to engine batteries. Gosh this is getting complicated! Kev - thanks for the link and that is the only other one as an alternative to Sterling that I have seen so far. I don't understand German but it seems to be 45 amp and is a similar price to the 50 amp Sterling B2B - and Sterling are only up the road from us which might be easier if it goes kaput! Link to comment Share on other sites More sharing options...
Guest Joe90 Posted March 31, 2015 Share Posted March 31, 2015 If you can get to the mains it seems a no brainer to simply do that ? and maybe adopt my cheapskate solution below. I can't get access to mains, but even in darkest Wales a 120 watt panel does the business through the winter, and being a cheapskate my solution to charging both leisure and engine battery is to merely have an admittedly longish length of 5 amp lighting type flex cable as the leisure battery and engine battery are some distance away from each other, but then the cable with crocodile clips and an inline fuse at either end to prevent the chance of a short, I first remove the fuses, then connect the crocodile clips to each battery, then replace the fuses, job done, of course my cable is removed and stowed by first removing the fuses then the croc clips before using the van, not elegant, but does the job with very minimal expense. Link to comment Share on other sites More sharing options...
colin Posted March 31, 2015 Share Posted March 31, 2015 Surprised you panel can't keep up, our van is kept under cover and the 85w panel still gets enough light to keep batteries charged in all months except december, although this year we have extended cover for second van and that may well cut out too much light for panel to work. If it's a problem might 'hang' a small panel on the bonnet which should keep the vehicle bat up to charge. Link to comment Share on other sites More sharing options...
Tracker Posted March 31, 2015 Author Share Posted March 31, 2015 On closer investigation I discovered that a wire to the B2B had come adrift - it looked OK but was not connected properly as it seems the guy who thought he had crimped the terminal to the cable hadn't. Never mind it's fixed now and I hope the next owner appreciates it! Thanks Joe - I've used your method too but instead of croc clips I used proper terminals and a dashboard mounted switch with a BIG reminder clipped to it to prevent me from blowing the fuse on start up! However as a 4 amp B2B is only about 25 quid is it really worth all the hassle? As far as solar goes I reckon that assuming each battery bank loses power to it's system at about 150 / 200 milliamps that equals 200 x 2 x 24 = 9600 milliamps or about 120 watts per day which needs to be made up just to stand still. In winter we are lucky to see 8 hours daylight so a minimum of 15 watts per hour is needed and given that efficiency of a solar panel can be as low as 20% in poor light that suggests even a 75 watt panel might struggle in winter? Well that's my theory and I would be happy for anyone to tell me my amateur calculations are all wrong! Link to comment Share on other sites More sharing options...
Guest Joe90 Posted March 31, 2015 Share Posted March 31, 2015 Tracker - 2015-03-31 5:11 PM On closer investigation I discovered that a wire to the B2B had come adrift - it looked OK but was not connected properly as it seems the guy who thought he had crimped the terminal to the cable hadn't. Never mind it's fixed now and I hope the next owner appreciates it! Thanks Joe - I've used your method too but instead of croc clips I used proper terminals and a dashboard mounted switch with a BIG reminder clipped to it to prevent me from blowing the fuse on start up! However as a 4 amp B2B is only about 25 quid is it really worth all the hassle? As far as solar goes I reckon that assuming each battery bank loses power to it's system at about 150 / 200 milliamps that equals 200 x 2 x 24 = 9600 milliamps or about 120 watts per day which needs to be made up just to stand still. In winter we are lucky to see 8 hours daylight so a minimum of 15 watts per hour is needed and given that efficiency of a solar panel can be as low as 20% in poor light that suggests even a 75 watt panel might struggle in winter? Well that's my theory and I would be happy for anyone to tell me my amateur calculations are all wrong! I only work in amps, (?) and I'm struggling to see how you calculate a loss of 120 watts which would equate ( I think ) to a draw of 10 amps a day just standing still, that sounds like a mighty big parasitic current draw to me, don't think I'd use that much with the van in use some days. Can only say my Kyocera 120 watt panel keeps everything hunky dory, but it wasn't a cheapo Ebay job, and even in prolonged spells of dull weather, not at all unusual to see outputs of 3/ 4 amps per hour mid winter even in this neck of the woods, just had a week off grid without EHU or moving the van, no issue with power starvation at all. :D I do take on board your comments viz B2B, perhaps I'll get round to it one of these days apart from the practicalities of hiding a ruddy great length of cable from the very rear to the front, as I don't really fancy half a day on my back underneath which would seem the be the only realistic option for a permenant job ;-) Link to comment Share on other sites More sharing options...
Will86 Posted March 31, 2015 Share Posted March 31, 2015 During the 6 years we had the Rapido ... and when at home which increased latterly ... the mains was connected all the time. One or two frowned at this but I always assumed that if the power controls were doing their job there would never be a problem ... and there never was ... the only query I had was that the leisure batteries need topping up often. Will Link to comment Share on other sites More sharing options...
Tracker Posted March 31, 2015 Author Share Posted March 31, 2015 Joe90 - 2015-03-31 6:19 PM As far as solar goes I reckon that assuming each battery bank loses power to it's system at about 150 / 200 milliamps that equals 200 x 2 x 24 = 9600 milliamps or about 120 watts per day which needs to be made up just to stand still. In winter we are lucky to see 8 hours daylight so a minimum of 15 watts per hour is needed and given that efficiency of a solar panel can be as low as 20% in poor light that suggests even a 75 watt panel might struggle in winter? I only work in amps, (?) and I'm struggling to see how you calculate a loss of 120 watts which would equate ( I think ) to a draw of 10 amps a day just standing still, that sounds like a mighty big parasitic current draw to me, don't think I'd use that much with the van in use some days. I do take on board your comments viz B2B, perhaps I'll get round to it one of these days apart from the practicalities of hiding a ruddy great length of cable from the very rear to the front, as I don't really fancy half a day on my back underneath which would seem the be the only realistic option for a permenant job Does this help - or further confuse? When you place the two leads of a digital mutimeter between the battery post and it's disconnected terminal the meter measures the current flow in milliamps and I believe that you know that 1000 milliamps = 1 amp? Watts = amps x volts so if the current flow is 200 milliamps, and it sometimes is even with everything switched off, that equals .2 amp x 24 hours per day = 4.8 amps. Double it, once for the engine battery and once for the leisure battery (ies) = 9.6 amps, which is why so many van batteries go flat in as little as two weeks unattended, and 9.6 amps x 12 volts = 115.2 watts in 24 hours. At least, I think it is! I take your point about the B2B and burying cable but with our van the leisure batteries are under the front seats and the engine battery is under the cab floor so it's easy peasey to connect a B2B. Link to comment Share on other sites More sharing options...
Guest Joe90 Posted March 31, 2015 Share Posted March 31, 2015 The only parasitic draw I've ever discovered on the leisure battery side is the hot water dump valve.......long since disconnected on every van I've owned with one, and replaced with a paper clip until the temps take a nose dive Engine battery another kettle of fish, but discovered the biggest culprit on our current van, the radio, I'm deaf as a post so that's also disconnected, but still as you say despite that the bloody thing would still go flat without my cheapo codge, funny as I can leave the car for weeks on end without issue when we bugger off over the channel .....................but it's not a Fiat :D Link to comment Share on other sites More sharing options...
Keithl Posted March 31, 2015 Share Posted March 31, 2015 Tracker - 2015-03-31 7:14 PM Does this help - or further confuse? Watts = amps x volts so if the current flow is 200 milliamps, and it sometimes is even with everything switched off, that equals .2 amp x 24 hours per day = 4.8 amps. Double it, once for the engine battery and once for the leisure battery (ies) = 9.6 amps, which is why so many van batteries go flat in as little as two weeks unattended, and 9.6 amps x 12 volts = 115.2 watts in 24 hours. At least, I think it is! Rich, Very nearly! What you have actually calculated is Amp Hours of capacity used! Not just Amps. (Think about it, you multiplied Amps by Hours hence get Amp Hours or Ah). So in 2 days you will have used 19.2 Ah, in 3 days 28.8 Ah and so on until your battery(ies) are flat! Keith. Link to comment Share on other sites More sharing options...
Tracker Posted March 31, 2015 Author Share Posted March 31, 2015 Keithl - 2015-03-31 8:10 PM What you have actually calculated is Amp Hours of capacity used! Not just Amps. (Think about it, you multiplied Amps by Hours hence get Amp Hours or Ah). So in 2 days you will have used 19.2 Ah, in 3 days 28.8 Ah and so on until your battery(ies) are flat! Keith. Thanks Keith, I did realise but I was trying to keep it simples by not introducing the time element! Similarly I missed out on the extra drain of system and cable and joint inefficiencies! Ever since the physics teacher hurled a blackboard duster at me whilst his foghorn of a voice yelled 'watts is volts times amps' it has been ingrained in my brain - much as the duster was intended to be embedded in it too - but I saw it coming and he missed! Link to comment Share on other sites More sharing options...
Guest Joe90 Posted March 31, 2015 Share Posted March 31, 2015 It's all going over my head, but suffice to say prior to having a solar panel my leisure batteries voltages held up for weeks and weeks on end, it was and still is the engine battery that suffers if not trickle charged now and again. ;-) Now I'll study water divining with my stick see if I can make any more sense of that. Link to comment Share on other sites More sharing options...
Tracker Posted March 31, 2015 Author Share Posted March 31, 2015 Joe90 - 2015-03-31 8:34 PM Now I'll study water divining with my stick see if I can make any more sense of that. I would have thought that Wet Wales had more than enough wind and water so maybe a sunshine divining stick would be better unless you can divine up some divine intervention! Link to comment Share on other sites More sharing options...
Guest Joe90 Posted April 1, 2015 Share Posted April 1, 2015 :D Dunno how we hack it here really :D Link to comment Share on other sites More sharing options...
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