tonyfletcher Posted October 20, 2009 Share Posted October 20, 2009 If I had a Leisure Battery rated at 210Ah and operated an appliance rated at 1500watts via a 2kw inverter how long would it be before the battery was discharged? I have purposly excluded a solar panel from this equasion, as that would be my next question, if I had a Solar Panel of say 85watts and was charging at 2.0amps under the same circumstances how long would it take to discharge the battery now? Cheers Tony Link to comment Share on other sites More sharing options...
Brambles Posted October 20, 2009 Share Posted October 20, 2009 I make it approx 42 minutes. 1500 watts with 20% loss in invertor = 1800 watts. 1800/12 = 150 Amps. 210 Ah battery to say 50% discharge = 105Ah (105/150) x 60 = 42 minutes. With solar panel supplying 2 Amps 150 Amps becomes 148 Amps = 42.5 minutes. You did not want this answer did you??! Jon. p.s. It actually is a lot worse because at 150 amps you will get no where near the capacity of the battery but more likely about 60 Ah available to 50% discharge. Also teh battery will probbaly not survive the high discharge rate for long and wil boil its head off and plates will distort. Are you trying to power a microwave by any chance? Link to comment Share on other sites More sharing options...
Randonneur Posted October 20, 2009 Share Posted October 20, 2009 Looks like a hairdryer to me. Link to comment Share on other sites More sharing options...
hymer1942 Posted October 20, 2009 Share Posted October 20, 2009 Morning Brambles, A good thread this, are you saying long use of the inveter will distort the plates, IE, sayperiods of 20 minute spells, or will the same thing apply if you say use it 10 times a day ffor 5 minutes. Regards Barrie Link to comment Share on other sites More sharing options...
Brambles Posted October 20, 2009 Share Posted October 20, 2009 hymer1942 - 2009-10-20 12:37 PM Morning Brambles, A good thread this, are you saying long use of the inveter will distort the plates, IE, sayperiods of 20 minute spells, or will the same thing apply if you say use it 10 times a day ffor 5 minutes. Regards Barrie Short periods of heavy use are better than a long constant period. A lot will also depend on battery construction, some are better than others. For example expanded metal plates (made from a sheet of metal pierced and than stretched out to form a mesh) is not as good as cast plates for heavy loads, but for low currents or quick bursts does not make much difference. There are many different types of detailed construction to battery plates and all have their own advantages or disadvantages. For contsant heavy currents you really need true traction type batteries but they are very expensive as lead content is so much higher. Technology has improved a lot though over the last 10 years and some of the available batteries are very good at coping with high loads and fast discharge but still like a rest period now and again. Link to comment Share on other sites More sharing options...
hymer1942 Posted October 20, 2009 Share Posted October 20, 2009 Thanks for that, very informative, nothing is ever simple. I bought 2 new lucas batteries a year ago and we have done 4 months europe up to now, head for Mojaca in Feb. for a 10 week trip and we give the inverter a fair lot of use so it will be interesting to see how the batteries hold up. Link to comment Share on other sites More sharing options...
tonyfletcher Posted October 20, 2009 Author Share Posted October 20, 2009 Hi Thanks for the calculation, I was trying a worse case scenario, in having an electric fan heater in the MH rather than using Gas. As we rarely use Hook Up abroad I was trying to become less reliant on mains. I currently have 2 x 85Ah rated Batteries and a 85 watt Solar panel. I was considering purchasing a 2kw Inverter for use for a Hair Dryer, Iron & Heater. I used the heater as an example as I thought it would be the highest user. They would all be used separately and not together Am I miles away from the happy medium?? Cheers Tony Link to comment Share on other sites More sharing options...
Brambles Posted October 20, 2009 Share Posted October 20, 2009 Using the batteries for heating is a no no really. For the Hair dryer and iron they are intermittant using battery power and is a practical solution if you require such items. Me I just put anything needing ironed under the settee for a day....it works and have lovely pressed trousers or jeans to parade around the campsite. Not being a lady I do not know the necessity of a hair dryer but have been told just let it dry freely and then use butane powered portable curling tongs/stylingtool to straigten, curl or whatever..what do I know, sounds sensible to me but do not want to patronise the ladies reading who insist on hair dryers and prove I know nuffink about a woman's needs! As to heating use gas. The money spent on invertors and extra batteries plus replacement costs as life is reduced could be put towards refillable gas bottles which is a much more practical solution to reducing costs of gas used. I have not worked it out but cost of replacing batteries more frequently would probably cover the cost of running a gas heater or paying for hook up. Wild camping with no hookup -- has to be gas or invest in a diesel heater like the Eberspacher . Link to comment Share on other sites More sharing options...
Guest Tracker Posted October 20, 2009 Share Posted October 20, 2009 Eberspacher works well but is very power hungry as it needs a burst at 10 amps just to fire it up, and that's every time the stat asks it to fire up, followed by between 2 and 4 amps continuous to keep it running. A cold evening in front of the TV with the heating on followed by a cold night with heating at a lower level will play havoc with your batteries. In theory it will not fire up at below 10.2 volts but in practice that is more like 11.8 volts indicated. We have two 110 ah batteries and a 60w solar panel and it's not enough power for a cold weekend, so much so that I'm thinking of either a third battery or a Stirling battery to battery charger because when the engine charges the leisure batteries it only does so at a miserly 10 amps. If I had the choice I would opt for gas heating every time but preferably with two 13kg gas bottles on board - one refillable and one Calor as back up. When Eberspacher is good it's very good but when it plays up it is a real pain as you nearly always need a service agent to sort it out and they are few and far between - even more so abroad. Link to comment Share on other sites More sharing options...
Bill Ord Posted October 21, 2009 Share Posted October 21, 2009 Hi, Unless I've missed something here you will not get 210 AH out of a 210 AH battery. More like 60% as it is unwise to totally discharge the battery and there are so many variables that the 60% figure is more realistic, perhaps Clive will come along and explain although he must be getting a little weary of repeating himself. Bill Ord Link to comment Share on other sites More sharing options...
Clive Posted October 21, 2009 Share Posted October 21, 2009 I don,t need to repeat myself as Brambles, Bill and co have covered it very well. For heat use gas. Its that simple. (Diesel if you must!) Mind you battery cooked toast and microwaved snacks have been known. But such heavy loads are only sustainable for a few minutes without clobbering your battery. Save precious electrical energy for important items - like the lights, controlling the heating, fridge, water pump, cooker ignition and TV!! C. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.