veletron Posted January 13, 2016 Share Posted January 13, 2016 Hi Anybody care to offer comment on the following: Leoch 160AH AGM: http://www.alpha-batteries.co.uk/leoch-160ah-agm-leisure-battery/ £179 Exide 140AH: Lead Acid: http://www.alpha-batteries.co.uk/140-ah-exide-caravan-battery/ £139 I can accommodate the extra height of these batteries, they will be paired, and I have no space to fit more than 2. As per previous thread, I am a heavy user of 12V power as I always wild-camp. - The on-the-move charger is a 50A Sterling Power B2B with a 14.7V/13.65V AGM setting (this has a temp sensor on the battery) - The mains charger is a nordelettronica 143 which has a gel setting - not ideal, but I very rarely use hookup (no battery temp sensing exists) - The solar charger controller is a fully programmable epsolar with remote LCD, I can change bulk/float voltages to suit AGM as necessary. This has a temp sensor on the battery. Total solar = 200W (or about 0.1A in winter!!) The battery will be located under the bench seat in a panel van, next to the truma combi heater (no other choice). It can get hot in here - maybe 40 degrees. If VARTA did an LFD140 making use of the additional height that would be a good option, but 2xLFD90's taken down to no more than 50% DoD are not going to fit my requirements. So... AGM (Leoch) or Open Lead Acid (Exide) ?? Nigel Link to comment Share on other sites More sharing options...
aandncaravan Posted January 13, 2016 Share Posted January 13, 2016 Your primary issue seems to be the temperature? Victron energy list their AGM Deep Cycle battery as having a 7 - 10 year life at 20 degrees but only 2 years at 40 degrees. This applies to most AGM batteries. The Exide will also get a hard time. Many AGM battery manufacturers state that the battery will tolerate high temperature use, but don't say the impact it will have on life. Even gel and AGM batteries can lose fluid at these temperatures and unless specially designed for sustained high temperature use can really pressurise the battery? That is especially so if also fast charged at high temperature. A Leoch is a quality battery, but in our experience batteries operated at temperatures of just 30 degrees suffer significant swelling and not unknown to burst. 40 degrees is a big ask of any battery? Received an email on the 9th Jan 2016 from Irene Stewart that said, "We have a " Schaudt. Electroblock EBL 269-3 Q060984 which was destroyed when a battery exploded in our van.....". People have questioned it happening, but we think it is becoming a more common event? A High Silver content wet battery will still 'suffer' at the higher temperature, but the impact on life can be less dramatic, plus the shorter life less costly. Maybe with the Exide you have the option of replacing any lost fluid? Battery temperature sensors work much better on a wet battery, as the free flowing acid moves up the plates by convection carrying away the heat from the Plates and bringing in fresh cooler acid. This generally means that the temperature on the external side of the Casing is relatively close to the Plate temperature. The Acid in an AGM or Gel battery is much less mobile so the temperature at the Case can be 10 degrees (or more) different to the plate temperature, which is obviously the critical point. So with use, your 40 degree case temp might actually be 50 degrees where the battery chemistry happens? You can maximise battery life at higher temperatures by drawing and charging at the lowest current you can. Note also that at most battery types will be less efficient at these temperatures, you are likely to lose 15% of storage capacity, a 100Ah battery may effectively be only 85Ah? A spiral wound AGM might work better at extreme temperatures? Tricky one. Link to comment Share on other sites More sharing options...
veletron Posted January 13, 2016 Author Share Posted January 13, 2016 Looks like the exide then - at least this is open, and I would vent via a tube through the floor - eg its not going to explode. Its a daft place to stick a leisure battery - the Mfr could have used this space for a drawer (eg for clothes), and turned the drawers to the rear of the van under the bed into a cooler location for batteries - or shifted the truma there instead. The exide would appear to be a quality battery anyway so I guess I go with that. Can we get Varta to make LFD's in more sizes?! The exide is listed as 'low maintenance' so I guess it can be topped up - it deffo has a vent tube location on it. Since my last post, the 2x 6 month old banners that I have have degraded further - down to 12V (no load) from 12.8V start after drawing just 40AH - they have had it. I have quit using the inverter. If I could get 2 years out of a pair of leisure batteries, I would be well happy! Nigel Link to comment Share on other sites More sharing options...
Tracker Posted January 13, 2016 Share Posted January 13, 2016 How practical or effective woyld it be to install a couple of silent low wattage computer fans to circulate warm air out of the locker and cooler air into it? Link to comment Share on other sites More sharing options...
veletron Posted January 13, 2016 Author Share Posted January 13, 2016 Tracker - 2016-01-13 1:28 PM How practical or effective woyld it be to install a couple of silent low wattage computer fans to circulate warm air out of the locker and cooler air into it? Pretty easy - good idea. I also believe that some of that silverised bubble insulation could be used to keep the heat from the boiler on the boiler's side of the under seat void. The boiler already has a huge vent hole in front of it as well as one to the rear. I have just ordered the Exide's I will be sure to report back on my relative experiences with these vs the banners. I got them for £115 ea after a discount for membership of the wild camping forum. Nigel Link to comment Share on other sites More sharing options...
aandncaravan Posted January 13, 2016 Share Posted January 13, 2016 If you can get the space down to a more reasonable 25 degrees, you could gain another 20Ah + capacity as well as longer life?. Link to comment Share on other sites More sharing options...
thebishbus Posted January 13, 2016 Share Posted January 13, 2016 Yes the fans sounds like a good idea, you could even have them temperature controlled so they only run when required. Brian B. Link to comment Share on other sites More sharing options...
aandncaravan Posted January 13, 2016 Share Posted January 13, 2016 Sorry, an error in my text, capacity does not drop as temperature goes up, Doh. Capacity goes down when temperature goes down. Apologies. Link to comment Share on other sites More sharing options...
Tracker Posted January 13, 2016 Share Posted January 13, 2016 aandncaravan - 2016-01-13 7:38 PM Sorry, an error in my text, capacity does not drop as temperature goes up, Doh. Capacity goes down when temperature goes down. Apologies. Thanks for the correction Alan! That's a relief! My batteries too are in the same compartment as the Truma boiler and I have just spent a while looking at how best to move them to the far end of the ajacent locker - but now I don't have to - even though it would have been quite a simple operation as the harness is plenty long enough! Link to comment Share on other sites More sharing options...
veletron Posted January 14, 2016 Author Share Posted January 14, 2016 Indeed, but longevity can suffer at high temps especially with high charge/discharge rates, and I dont believe the AGM's would like it overall. At least an open battery is unlikely to explode. In truth neither should an AGM, rather, the pressure valve should have opened to release the pressure build up. Anyway, when the exides turn up, I will do the same run down test i did before, and report the results vs the 6 month old banners. Ditto in another 6 months such that there is a reasonable comparison. Nigel Link to comment Share on other sites More sharing options...
veletron Posted January 18, 2016 Author Share Posted January 18, 2016 Hi Exide 140's received and fitted (Alpha batteries, £115ea after the wild-camping forum discount). Very tall as expected, had to modify my self-made battery tray to fit the 2nd battery. Went up to Glenshee this weekend skiing. Pulled 76AH net from them over the weekend, with the off-load voltage showing 12.6V by the end of the weekend. Consistently sub freezing with lows of -8 so they had plenty to do. My 7-month old banners would have been under 12.2V after a similar power draw. Pleased so far, but lets see how they are in 6 months time! Nigel Link to comment Share on other sites More sharing options...
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