bertieburstner Posted May 17, 2012 Share Posted May 17, 2012 Apologies if this topic has been covered before. We have a motorhome with 2 x 110AH leisure batteries, 4 years old (batteries and m/h). We have camped without hook up for 3 days before with no problems, without starting the engine. This weekend however the battery level went down to 10.5 volts and we had to get on the road before we could have a shower! We had watched 12 volt 15" TV (Avtex) for about 5 hours in total and had 8 showers. We had also used the heating on gas, Truma blown air system. Our lighting is all halogen. I don't think it was much or any more than we had used previously and before the meter reading was still 12.6 volts. My questions are1. were we just lucky before 2. Are the batteries on the way out and if so is there an easy way to test them They are sealed units. 3. Is it worth changing the lights to LED. We are considering a solar panel and would have space on the roof. Link to comment Share on other sites More sharing options...
Guest Tracker Posted May 17, 2012 Share Posted May 17, 2012 Battery voltage readings off load can sometimes lead one into a false sense of security as you will probably find that as soon as something 12v is turned on the voltage plummets. Charge the batteries fully with the on board charger for a day or two so they are beyond any doubt fully charged and then disconnect both of the batteries from the circuit and from each other. At that time take a voltage reading of each and you hope for about 12.8 volts. Leave them disconnected overnight and check the voltage again. Do this for up to a week and if the batteries are good the voltage will hold around 12.7 to 12.8 volts but if they are suspect the voltage will drop further. At four years old they might well be in need of renewing but on the other hand plenty of folk get a lot more than 4 years out of batteries. I would certainly add a solar panel but do be aware that because it keeps the batteries charged in daylight that too can mask duff batteries which may well only become apparent at night when they are not getting any charge so the pre-requisit for an effective solar system is good batteries to start with. It has been covered before - many many times - and a trawl through past posts using the search facility will give you hours of joyful reading! Link to comment Share on other sites More sharing options...
bertieburstner Posted May 17, 2012 Author Share Posted May 17, 2012 Thanks Tracker excellent I'll get busy! (lol) Link to comment Share on other sites More sharing options...
Brambles Posted May 17, 2012 Share Posted May 17, 2012 Youir batteries may noyt have stated the trip charged and omnly charge they goyt was on way there asn was not enough. Trackers fuly charging sugegsted wil soity this ouy. Batterues do age and capacity reduces exponentially with age and use. So basically your battreies may just be down in capcacity adn where before they could go three nights now just do two nights. Fitting a solar panel will extend their usefullness and reduce aging as they would not discharge so deep, but at the end of the day there is no substitute for fitting new batteries. Then consider a solar panel to keep them in good condition. Personally I feel if two 110 amp batteries provide what you need then why bother with a solar panel and just replace every few years and accept as part of running costs. On the other hand, a solar panel wil help keep then charged and provide that bit of extra power should you need it. I just start my on board generator and run it for a bit, the generator which comes as standard on all mororhomes!!! Link to comment Share on other sites More sharing options...
Guest Tracker Posted May 17, 2012 Share Posted May 17, 2012 Brambles - 2012-05-17 8:27 PM On the other hand, a solar panel wil help keep then charged and provide that bit of extra power should you need it. I just start my on board generator and run it for a bit, the generator which comes as standard on all mororhomes!!! Me too! However it only bungs about 10 amps into the leisure batteries these days with all the mamby pamby regulations about charging regimes so if you have two flat 110 ah batteries you may need to run the engine or drive for some 20 hours to fully charge them both - and that is after the vehicle battery has fully charged itself! Strong argument for always leaving home or site ehu wth fully mains charged batteries! Link to comment Share on other sites More sharing options...
Brambles Posted May 17, 2012 Share Posted May 17, 2012 Not strictly true Tracker. Lets fall for an average of 10 amps and could be a lot less like just a couple of amps, but when low on charge they could easily draw 20 to 25 Amps depending on battery and cable sizes. The rate of charge is dependent to a very large extend on the depth of discharge. I know where you are coming from though and is easier just to say 10 amps as an average. Alernator outputs drop the regulated viotage deliberately as load increases so that also reduces the charge current but is stil possible to get a hefty charge current between say 40% charge level up to say around 70% charge level from the alternator. Hence the 40 Amp fuse and not a 15 Amp fuse. Link to comment Share on other sites More sharing options...
Guest Tracker Posted May 17, 2012 Share Posted May 17, 2012 Jon, I based my 10 amp theory on what I measured with a 20 amp multimeter to be the maximum charge that hit my semi discharged 110 ah leisure batteries when, like so many before and since, I was having problems and trying to identify what the issues actually were some three years back. Subsequent investigations led me to understand that the 10 amp restricted charge rate is quite deliberate and that much more than 10 amps will never get through to the leisure battery from the alternator because of the cable size and electronics used? The fuses commonly used in the split charging systems that I have seen seem to be 30 amp and I understood this was to avoid a start up surge blowing the fuse rather than as an indication of current capacity? As I said I am no expert other than what I have learnt from this forum, from googling, and by trial and error but it comes as something of a surprise to now learn that 20 to 25 amps can get through to the leisure batteries because mine sure don't? For those who wondered - my problems were duff leisure batteries - one Elecsol two years old and one obscure make whose name escapes me now which was three years old and I solved it once and for all with two new 110 ah Varta batteries and the addition of a 60 watt solar panel and regulator at that time 3 years ago with no problems at all ever since. I do disconnect the Varta's now and again to let them stand for a week or so to check their voltages and they hold up very well with only a minimal drop from around the 12.8 volt fully charged level. Link to comment Share on other sites More sharing options...
BGD Posted May 17, 2012 Share Posted May 17, 2012 Personal view: in your shoes my top priority would be to dump those halogen lightbulbs. Now. Every 12 volt light bulb in your MH should be LED. That'll give you loads more battery life to use up elsewhere. We've got 125 watts of solar panels and two, 125amp leisure batteries, ans we can go 4 or 5 days static without alternator charging, using 12 volt TV, water pump, lights, blown air heating fan ( Although we do get a lot of sun down here). Link to comment Share on other sites More sharing options...
Guest Tracker Posted May 17, 2012 Share Posted May 17, 2012 Possibly Bruce? Depends how many lights you use and for how long? When the tv is on during a dark evening we only have one 6 watt fluorescent light on most of the evening as it is easily enough to light up the van interior. Other lights like spotlights, kitchen, loo etc only get used for brief periods when extra light is needed and consume next to nothing so I don't see buying expensive leds as the way forward - for us at least? Maybe if two people spend every evening reading with two 12 watt halogen spotlights on and a couple of interior lights as well - but even then that's only about 3 ah for say 5 hours = 15 ah - hardly battery flattening I would have thought when you have solar panels to recoup the used energy every day? Link to comment Share on other sites More sharing options...
bertieburstner Posted May 24, 2012 Author Share Posted May 24, 2012 Thanks for all your help folks having disconnected the batteries a week ago they are still showing fully charged which is encouraging. I shall now look at a solar panel and possibly LED's. :-D Link to comment Share on other sites More sharing options...
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