Jack Posted March 18, 2021 Share Posted March 18, 2021 The motorhome is a Hymer B544SL The panel is a DT201 and the electrics are controlled by a Elerktoblock 101 and finally the battery is a DETA DG80. The battery is at least 7years old but could be the original 14years! it has never given any indication that it it is about to die, it is on electric hookup and has a solar panel feeding the batteries also. Off grid camping has been our usual use, not since end of 2019. Now to the issue: The habitation is showing 13.8v but the Ah is showing 40 along with an indication to "charge!" Is this an indication that the battery is performing at half its capacity? Therefore, should I be thinking of changing? Supplementary question, if so what would be a suitable replacement? Many thanks Link to comment Share on other sites More sharing options...
Brian Kirby Posted March 18, 2021 Share Posted March 18, 2021 If these readings are with either the solar, or mains charging, operating, you'll need to turn off both charging sources as you're probably reading the charger (whichever it is) output voltage. Then, leave the battery to stand with no load for 4 hours or preferably more, and have another look at what the panel says. I suspect you'll then see a significantly lower voltage reading. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted March 18, 2021 Share Posted March 18, 2021 Jack I notice that you mentioned your DETA DG80 leisure battery here in 2014... https://forums.outandaboutlive.co.uk/forums/Motorhomes/Hints-and-Tips/Hymer-Battery/36228/ Given the age of the battery (7 years minimum, but possibly much older) I would have thought replacement would be well overdue. This Exide gel equivalent would be a strong contender. https://www.tayna.co.uk/leisure-batteries/exide/dg-80/ (My 2005 Hobby motorhome had as standard an Exide G80 gel leisure battery. It provided good service for 7 years and charged OK, then died with little warning. A battery specialist told me 'sudden death' was not uncommon for gel batteries.) Link to comment Share on other sites More sharing options...
StuartO Posted March 18, 2021 Share Posted March 18, 2021 To answer your question about what 40ah on the display means, the EBL101 with DT101 displays a figure for remaining battery capacity which is calculated using current flow in and out of the battery so assuming the battery’s maximum capacity was set correctly when the battery was installed, it takes two or three days of use to acquire a calculated reading and the figure is displayed with a “?” until that figure is ready for display. While on EHU it would show the battery’s maximum capacity. I agree that your battery should be replaced an an Exide gel G80 would be a good choice. If you go for that make sure the little switch for gel or lead acid is in the gel position. My Exide G80 was still going at ten years old. You could save money as I did (as favoured by the late Allan Evans) by replacing with a Varta LFD90 (half price but a shorter life) but in that case the little switch should be set to lead acid before battery installation. Link to comment Share on other sites More sharing options...
plwsm2000 Posted March 18, 2021 Share Posted March 18, 2021 I have a DT220 panel that will display the "Charge!" symbol if you change the battery capacity in the menu. I think you have to hold the menu button down for a few secsonds to do this so could be done by accident. If you "OK" it in this menu, the display will default to HALF of the capacity and display the "Charge!". This will happen even if your battery is in good condition and fully charged. Assuming your battery capacity was set to 80Ah, this will give the 40Ah and "Charge!". Leaving it on charge for a couple of hours normally resets it back to 80Ah (or whatever) assuming your battery is still ok. Although it might not be a faulty battery causing this, it is quite old and probably needs changing soon in any case. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted March 19, 2021 Share Posted March 19, 2021 StuartO - 2021-03-18 6:13 PM ...You could save money as I did (as favoured by the late Allan Evans) by replacing with a Varta LFD90 (half price but a shorter life) but in that case the little switch should be set to lead acid before battery installation. Replacing a DETA DG80 gel battery with a conventional wet-acid battery (eg. a Varta LFD90) means that - although the LFD90 is ‘non-maintainable' (like the gel battery) - the LFD90 is designed to accept a vent-tube. I’m well aware that Allan Evans used to suggest that a Varta LFD90’s potential for ‘gassing’ was minimal IN NORMAL USE, but it’s nevertheless the case that, unless the LFD90 is in a well ventilated locker hermetically sealed from the motorhome’s interior, a vent-tube should be fitted. (And even if a LFD90 is in a well ventilated locker hermetically sealed from the motorhome’s interior, fitting a vent-tube would still be wise). The online cost of an Exide gel battery is around £158 and of a Varta LFD90 around £99. Probably simpler to stay with gel (and forget about venting) unless Jack wants to double-up the batteries to a pair of wet-acid type as he enquired about doing in 2014. Link to comment Share on other sites More sharing options...
ageingandrew Posted March 19, 2021 Share Posted March 19, 2021 StuartO - 2021-03-18 6:13 PM You could save money as I did (as favoured by the late Allan Evans) by replacing with a Varta LFD90 (half price but a shorter life) but in that case the little switch should be set to lead acid before battery installation. That really is a false economy. The LFD is about £100 and the Exide gel around £160, but the gel will last many years longer than the LFD; it will provide more recharge cycles and can be discharged a greater depth than the 50% limit of the LFD. I think the Exide product literature states that it can be discharged up to 80% of its capacity. The gel has so many advantages over the LFD (no fluid checks needed, no risk of leaks, repeat deep discharges...and more) that I cannot see any circumstances where such a downgrade to the LFD would make sense if you're going to keep your van any length of time. Link to comment Share on other sites More sharing options...
Jack Posted March 19, 2021 Author Share Posted March 19, 2021 Thanks for all the replies. I will do what Brian suggested and see what reading I get. However, I can see I have been well served by the Deta battery and does not owe me anything! Thanks again. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted March 20, 2021 Share Posted March 20, 2021 I suggest you don’t rely on the control-panel for diagnosis of your leisure-battery’s health. Make sure the battery is fully charged, which should occur if the motorhome is connected to a 230V mains power supply and its onboard battery charger has been operating for at least 24 hours. Next disconnect the motorhome from the 230V power supply and turn off the supply from the solar panel (or cover the panel). Now place a significant load on the leisure-battery by switching on all the habitation-area lights and the gas space heater and see what happens. If the battery can cope with that load for a while it may still have some useful life left in it but - given its age - there’s a good chance it will stagger very rapidly. I’ve had batteries that would charge OK and hold a reasonable ‘no load’ voltage, but crash dramatically when any sort of load was placed on them. Link to comment Share on other sites More sharing options...
Jack Posted March 21, 2021 Author Share Posted March 21, 2021 Just to keep your interest going... or not :-) Having done what Brian had suggested (24hrs) and as he expected the battery has dropped 12.9 but the Ah has dropped to 29! Given that reading I have not subjected the battery to the stress load that Derek advised. It seems to me the DETA is calling it a day . Now I was all set to purchase an Exide gel equivalent but I have been presented with a bit of a quandary. A friend has offered me an unused Lion leisure battery 110LB. (bought for his caravan but not installed) which has been kept charged using a trickle charger periodically. I am assuming it is not a gel battery but it is sealed. Accepting this is perhaps an inferior battery to the one I was considering, I can't see any down sides to using this gift, am I missing something? Link to comment Share on other sites More sharing options...
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