PGA Posted July 15, 2013 Share Posted July 15, 2013 Like so many, I am afraid I am starting my forum career asking for advice. We have a 110 ah pb/acid battery with a Sargent EC155 PSU on a 2013 Renault Master. We get our Waeco CR80 compressor fridge down to temperature on EHU but are having problems managing off EHU for more than about 6 hrs. We are told we should be alright for 24-48hrs. The fridge starts and runs normally up to X 3. The current rises above 6amps and then slowly drops as I have been told it should. Next time the compressor starts but drops out after a few seconds as the amps rise to about 5. The cycle repeats, cutting out at progressively lower amps, coinciding with a volt drop to 11-. A failed battery was diagnosed and replaced under warranty but the problem has recurred. The electrical system has been pronounced OK by the convertor. They have arranged for Waeco to check that the fridge is OK. The 2nd battery holds voltage off load. Recently it was 12.88v. I put it on EHU for 18hrs. The EC155 charges at 12amps at 13.8v, so I hope that was enough. After 45mins off EHU the p.d. was 13.18v. I then plugged in a cool box drawing just over 4 amps, checked via battery fuse. Within 2.5hrs the low voltage cutoff operated. Off load the voltage went to 12.47. On load it dropped fast to 9.3v. I then put it back on EHU. Is the 2nd battery faulty, fluid covers plates in all 6 cells, or are we expecting too much from the system? Advice from all the knowledgeable folk on the forum would be appreciated. Link to comment Share on other sites More sharing options...
Brian Kirby Posted July 15, 2013 Share Posted July 15, 2013 Just for completeness, did you have anything else drawing current at the same time as the fridge? There has been some problem with Waeco cool boxes, I think mainly concerning models fitted to "high end" cars, so I guess a duff coolbox is possible. I think it may help if you were to turn off the fridge, fully charge the hab battery (say 24 hours), leave it to stand with no load for about 6 hours, and then take a voltage reading. After that, turn on lights to create a load of say 5A (if you van has tungsten lamps, three 20W spots, or whatever else you have to provide a known load in about the same range), and leave them on, but check and note the battery voltage every couple of hours, and see how it changes. If the battery is a genuine 110Ah (not all are what they claim to be, so it might help if you can say what make and model the battery is) you can reasonably expect to take 55Ah from it without causing damage, so the test should run for about 10hrs +/-. If the battery is duff you will see a far quicker rate of voltage drop. Hope this helps to get the ball rolling. :-) Link to comment Share on other sites More sharing options...
colin Posted July 15, 2013 Share Posted July 15, 2013 Not necessarily an answer to your problem, but something to consider. Have you got a solar panel? On our old van we had an electric fridge and a solar panel and they worked very well together, as generally, the sunnier and hotter it is the harder the fridge has to work, but also the more the panel outputs. Link to comment Share on other sites More sharing options...
crinklystarfish Posted July 15, 2013 Share Posted July 15, 2013 Shouldn't need one to compensate for that amount of use. Something is definitely not right. Fridge and coolbox current seem plausible and ball-park so suspect bad luck with batteries. I'd personally start with a known good battery to at least eliminate that as a cause. Link to comment Share on other sites More sharing options...
PGA Posted July 16, 2013 Author Share Posted July 16, 2013 Thanks for the replies. The present battery is labelled 'SLB 110 Weekender Marine/Leisure battery'. I can't see any specific manufacturer's name and Google doesn't bring anything up about it. The original was an Elecsol but it may have been abused before we collected the van. As it happens, I was running a 2nd test while posting yesterday. I had charged the battery for 48hrs and then put on a number of lights, which gave a current of 2.16 amps, measured via the battery fuse again. The voltage on load fell from 12.69 to 12.57 over 3hrs. Sometime between 3 and 4.5hrs it dropped below cut off level, 9v on the EC 155. Off load at that point it was 12.6 but as soon as I put it back on load it fell rapidly and was below 10.3 when I aborted the test. Although I had not left it for 6hrs before starting the test, I have left it off load and EHU for days in the past and it has only lost about 0.04v/day, keeping up around the 12.9-13.0v mark. We certainly may consider a solar panel in the future, but want to get this short battery life sorted first. I'm glad the original figures I gave sound sensible, reassuring when previous electrical measurement experience was decades ago. Looks like we may be looking at another new battery but a recognised name this time. I see Varta, Banner and Exide recommended. Link to comment Share on other sites More sharing options...
Brian Kirby Posted July 16, 2013 Share Posted July 16, 2013 I think the verdict is inescapable, and the battery is a dud. I would add that from what you have said it was probably never suitable for the intended use, and I rather doubt it is actually 110Ah capacity. The makes you mention should all be good, but I suggest you see what you can get, and then come back here for further advice before buying, as there are a couple of forum members whose depth of knowledge of batteries, and their technology, is immense. If you have not come across the firm before, do a "Google" for Tayna batteries, or follow this link: http://tinyurl.com/2vrtptd They have a reputation for giving a reasonably honest appraisal of the batteries they sell. The simplest clue to quality for leisure batteries seems to be weight - the heavier the better for any given claimed capacity. The weight comes from the thickness of the lead plates, the thicker the plates the longer the battery is likely to last, and the more likely it is that the claimed capacity will be an accurate statement. If you wish to do a little preparatory research, use the forum search facility above, select "Motorhome Matters" as the forum to search, set "Date Limit" to All posts, in "Filter by author", enter Brambles, and under "Keywords" enter leisure battery. You will get loads of stuff, including a virtual battery master-class in this string: http://tinyurl.com/mvu9rpx. Link to comment Share on other sites More sharing options...
PGA Posted July 21, 2013 Author Share Posted July 21, 2013 Thanks for the search tip Brian. Masses of interesting information to digest there. Link to comment Share on other sites More sharing options...
Tracker Posted July 21, 2013 Share Posted July 21, 2013 Welcome top the madhouse PGA and don't worry about asking as that is how most of us started on here! As your van is 2013 I assume that everything is under warranty? If so maybe it's time to start being firm with the supplier? It is not at all unusual to have to try several allegedly new leisure batteries before getting a good one as the quality and consistency of many makes of them leaves a lot to be desired. Personally with a compressor fridge I would want 2 x proper 110 ah leisure batteries with as big a solar panel as I could get, with regulator and for good measure, a split charge system to keep the engine battery full as well. This earlier thread might help give you an insight? http://www.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/Leisure-Batteries-Con-/31156/#M366279 Link to comment Share on other sites More sharing options...
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