RustyNissanPrairie Posted June 23, 2009 Share Posted June 23, 2009 I currently have a 110AH Lucas Leisure battery as my main starter battery which powers also powers my Waeco CF40 fridge. The fridge has a selectable low voltage cut off range which leaves enough power in the battery to start the engine again but you can tell its getting down in voltage. The battery will power the fridge for a good 2 days or more without running the engine. I plan on adding some LED internal lighting as well as wiring in my external LED worklamp but also adding a 2nd Lucas 110AH battery. Im thinking of fitting a National Luna 2 battery monitor (not the split charger) and a marine style manual battery selector switch which allows a choice between running off battery 1, 2 or running them both in parrallel if needed for starting once the fridge has run down to its cut off point. The reason being that because the fridge has a selectable voltage cutoff why not use it on both batteries (whilst still leaving enough power in either battery to restart or together in parrallel should the temps really drop) rather than just completely draining the auxiliiary and leaving the starter battery fully charged as would happen with an Engel or equiv fridge and a standard split charge setup without the voltage selectable cutoff. Any thoughts/draw backs? Quote Link to comment Share on other sites More sharing options...
ChrisM_110 Posted June 23, 2009 Share Posted June 23, 2009 I just used this style [simple 40A] relay on both my VW Camper and my Landy. Works fine with a 100A alternator. Nice heavy gauge cable, good quality connections [no Scotchloks] and short cable runs. I used a 40A relay, 40A fuses, and cable. The only time I blew a fuse was when I jump started the main battery from the leisure battery without removing the fuse. Not as flexible as you may want but very simple and easy to do. Also cheap, which is a good thing. Quote Link to comment Share on other sites More sharing options...
LandyManLuke Posted June 24, 2009 Share Posted June 24, 2009 Fair enough on the manual battery selector, more robust than a 40A relay - as long as you remember to switch it as and when required. Why the National Luna 2? what does it actually offer you? very little in my opinion, for what it costs. Quote Link to comment Share on other sites More sharing options...
landy andy. Posted June 24, 2009 Share Posted June 24, 2009 What battery monitor do you recomend? £40 for a dual battery monitor does not seem bad....................... Andy Quote Link to comment Share on other sites More sharing options...
LandyManLuke Posted June 24, 2009 Share Posted June 24, 2009 I've usually a multimeter in the 90, that's much more flexible than a fixed monitor. If you want an LED barscale or voltmeters for each battery they can both be made for a couple of quid. I appreciate that doesn't suit everyone. Quote Link to comment Share on other sites More sharing options...
western Posted June 24, 2009 Share Posted June 24, 2009 or 2 x VDO 12v voltmeters. Quote Link to comment Share on other sites More sharing options...
LandyManLuke Posted June 24, 2009 Share Posted June 24, 2009 I agree, but I bet they're more than £40 for a pair? Quote Link to comment Share on other sites More sharing options...
western Posted June 24, 2009 Share Posted June 24, 2009 I agree, but I bet they're more than £40 for a pair? my 2 were 28 quid each IIRC, but now 31. here the national luna unit don't look to be any cheaper, no prices on their website. Quote Link to comment Share on other sites More sharing options...
ChrisM_110 Posted June 24, 2009 Share Posted June 24, 2009 I agree, but I bet they're more than £40 for a pair? How bout £30 the pair? Ralph just reminded me, my twin voltmeters were £13 each, from a Citroen 2CV racing supplier of all places. They've gone up to £14:95 here. I have one [main] in the console where the clock would go, and one [leisure] in the 'centre console' where the square clock goes. Quote Link to comment Share on other sites More sharing options...
PaulMc Posted June 24, 2009 Share Posted June 24, 2009 How bout £30 the pair?Ralph just reminded me, my twin voltmeters were £13 each, from a Citroen 2CV racing supplier of all places. They've gone up to £14:95 here. I have one [main] in the console where the clock would go, and one [leisure] in the 'centre console' where the square clock goes. Linky no worky This one does - http://www.2cvstuff.com/2CV_oily_stuff.html Quote Link to comment Share on other sites More sharing options...
alfaman Posted July 11, 2009 Share Posted July 11, 2009 or 2 x VDO 12v voltmeters. How 'bout 1 Gauge with a switch? Quote Link to comment Share on other sites More sharing options...
The Badger Posted July 11, 2009 Share Posted July 11, 2009 I used to have a Genesis split system, this came with a cost and nice little controller that enabled me to link the main batteries at a press of a switch, and when needed for winching, also showed the power level of each battery. This time around I am using a simple HD albright relay and one voltmeter. Now I reckon I should have another one so I can view both batteries as it does make sense it you have two batteries and want to know the level of each one. I guess it's down to preference if you want to know how much power each battery has as one voltmeter show the charge of the main one only if it is wired off the ignition (I think thats right anyhow) Quote Link to comment Share on other sites More sharing options...
western Posted July 11, 2009 Share Posted July 11, 2009 How 'bout 1 Gauge with a switch? Yep, can be done, a friend [Earl] on here has done that on his old 300Tdi 110 & to his current Td5 110, just a 3 position toggle/rocker that has a centre off position & a single 12v voltmeter, works for him. Quote Link to comment Share on other sites More sharing options...
The Badger Posted July 11, 2009 Share Posted July 11, 2009 That's nice and simple, would one wire be off the ignition and the other off the positive on the other battery? Quote Link to comment Share on other sites More sharing options...
alfaman Posted July 11, 2009 Share Posted July 11, 2009 ... a 3 position toggle/rocker that has a centre off position & a single 12v voltmeter, ... . I used a relay instead of a 3 pos'n switch. When engine is running, it displays the Main battery. Flicking the switch shows the AUX battery via relay. If I forget to switch back , I aint draining the Main. Keith. Quote Link to comment Share on other sites More sharing options...
western Posted July 11, 2009 Share Posted July 11, 2009 That's nice and simple, would one wire be off the ignition and the other off the positive on the other battery? should work like that. mines is wired 1 voltmeter on the original wiring [as my 110 had a vlotmeter fitted from new] & 2nd via a ignition controlled relay [shuts power off to relay/gauge when ignition is switched off Quote Link to comment Share on other sites More sharing options...
Ex Member Posted July 11, 2009 Share Posted July 11, 2009 Personally, I would go digital. Small changes in voltage tell you a lot about battery condition and charging. I just have a switch to read voltage from each battery. http://www.casporttouring.com/store/mercha...ode=Electronics Quote Link to comment Share on other sites More sharing options...
gazelle Posted July 12, 2009 Share Posted July 12, 2009 The setup you are describing is the simiar to that used on some yachts : An engine start battery on one circuit, isolated from the domestic on the other, but both charging from one alternator. You can get some ideas from marine electrical books. PM me if you want to know more and I will see what I can dig out for you. The marine usage stuff is designed to be used in a horrible salt rich enviroment, so is overkill for vehicle use. The charging circuit on our yacht has a diode based splitter on the alternator output, which means we never have to worry about switching between batteries. The batteries can be linked together by a separate switch if we have a problem with the engine start battery. We have also installed (on the domestic battery only) a voltage/current/capacity meter - I know this costs a lot more, but it will give you a better idea of where you are with the battery if you are going to be running the electrics for some time without running the engine. It also gives you the current draw that can give you a better idea of how long you have before the battery runs out! Our setup on the boat has less input than some as it is used for chartering and needs to be as simple as possible! Cheers Martin Quote Link to comment Share on other sites More sharing options...
gazelle Posted July 12, 2009 Share Posted July 12, 2009 The arrangement above is something like the following diagram (will confirm if not when I get to have another look at it). The ammeter shunt is found next to the domestic battery. The voltage meter covers all 3 batteries on board. Sorry about the poor drawing - got hold of some freeware which I have never used before to produce it! Martin Quote Link to comment Share on other sites More sharing options...
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