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Hello
I’m a new member and hope you can help me.
I have an Optima 65 GE 2017 and can’t get my head around the charging system?
I’ve got it hooked up to mains but the battery charging starts Ok but after 2-3 days the battery voltages go right down below 12v and the charger just doesnt kick in?
Does anyone know why?
The instruction manual says about the battery getting down to 8V but surely thats not correct?
Thanks
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Hi Adam,
That reference to the battery charger only working when the battery voltage is below 8volts cannot be right. As you say it is recommended that you don’t let a lead acid/AMG/Gel battery drop below 50% charge, so about 12.2 v or so. The charger should cut in as soon as you are on EHU and will remain on charge or float at all times. I leave my MoHo on EHU all the time when at home and the charger is “smart” so it just trickles any additional charge that the solar is not doing.
I don’t sound as though your charger is working or your battery is completely goosed. Either way you should be able to find out by using a volt meter on your battery ie voltage with EHU and charger on at about 14.5 volts or so initially dropped back to about 13.4 volts when the battery is fully charged. You could try fully charging the battery then disconnecting it and see how is retains the charge over several weeks. A good battery should hold up at say 12.5 v over 2 months with no load on it.
Obviously I don’t know how confident you are with electrical issues or what exact set up you have in your MoHo. But if your MoHo is a recent purchase from a dealer and you are having problems with it, your first move is to get them to sort it. If they are not familiar with the Hobby kit then they should be the ones engaging a competent electrician to sort it, not you worrying about it.
It is quite common for MoHo’s to sit around in dealers yards for a while and the battery’s go flat or good ones are swapped to other vans etc. If you push you may well find the dealer will replace the battery for you at the very least.
Final though, have you checked the fuses and connections relating to the charger? The electrical system can seem complicated but just take things logically from the EHU – ECB- fuses- charger- wiring connections- battery- control panel. Checking the Voltage and Amps as you go. If all else fails or it is overwhelming , just give your dealer a hard time until he sorts it.
Hope some of that helps.
Peter
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Hello Peter
Many thanks for your response.
From my manual it mentions that the battery is only charged if it has a minimum voltage of 8V, well I have always thought that batteries should preferably stay at a minimum of 12.5 volts and above, and that if allowed to get below this is damaging to the battery. I don’t really understand why the charger doesn’t just maintain the voltage from 12.5 upwards. As far as I know nothing is switched on, but I find that both batteries will go down to less than 12.5 volts in about 3 days, even when hooked up to the mains.
I think I will try contacting Hobby directly to try and find out what the correct charging strategy is, and find out the logic to it.
When I approached the dealer I bought the motorhome from they didn’t seem very knowledgably about my particular hobby, so I’m reluctant to get them involved since I’m not confident they have the relevant expertise.
Regards, Adam -
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Hello Paul,
Your van is newer than mine so some of the electrics will be different. However from what you you say it sounds a though your battery charger is not working. Normally on hook up (assuming your external electrical point is live, your cable and connections are good and your MoHo ECB is on ) you should be seeing about 14.3 volts going into your habitation battery. After your battery is fully charged and you disconnect the EHU the full voltage will settle at about 13.5 volts after a couple oh hours. dependant on your battery type.
If your battery charger is charging ok and your battery is loosing voltage over a couple of days, you either has something switched on that is drawing power or your battery is in need of changing. Have you checked that the light in the garage or Waldrobe have not been left on for example?
Another issue is that lead, gel or AGM batteries should not be discharged below 50% or they will be damaged and their life severely shortened. Therefore if the batteries have been often run down or left in a discharged state, they may well be finished.Final though, do you have a volt meter and an amp meter. They make calf finding so much easier.
Hope some of that helps and I am not trying to teach my Grandmother etc etc.
Cheers
Petef
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