Neil 35 Posted April 20, 2020 Share Posted April 20, 2020 Probably a dumb question but here goes. Just before lock down we came back from a few days away and I did what I normally do and put the house batteries on charge. It's a decent charger, galvanic isolated with multi step regulator etc (from memory I think it ends up in a sort of "maintenance state" or something like that). Ordinarily I remove the charger next time I go down knowing they are fully topped off... but...you know...COVID. Any issues with it being sat on the charger for months at a time? Or should the multi-step regulator keep it all in good shape? Thoughts anyone? I could get someone to switch it off at the shore end if needed but not sure it's a problem? BTW they are pretty new batteries, both same brand and 100 and something Ahrs each so they should be in good order to start with. BTW2 being at home all day means I get a lot of time to worry about stuff I probably shouldn't worry about! Quote Link to post Share on other sites
Black Panther 1,776 Posted April 20, 2020 Share Posted April 20, 2020 My understanding is the regulator takes care of that. But IT is the expert. 1 Quote Link to post Share on other sites
Deep Purple 530 Posted April 20, 2020 Share Posted April 20, 2020 I hope it's okay because I've got two C-Teks running out at the hangar. I had another charger on as well but as I couldn't establish it's maintenance ability so I disconnected it. I've just been told I'm allowed to do a maintenance run on the plane, no flying though , so i'll check them out this week. Luckily the boat has a very good solar system so thats not a worry 1 Quote Link to post Share on other sites
Island Time 1,313 Posted April 21, 2020 Share Posted April 21, 2020 Theoretically they can stay on a "maintenance" or "float" charge indefinitely. In my experience though, I've seen batts prematurely die with this regime - over years though, not months. I'm not sure why this is. On my own boat I use shore power to run the fridge at the dock, but leave the batt charger off - solar keeps batts full. 1 Quote Link to post Share on other sites
Deep Purple 530 Posted April 21, 2020 Share Posted April 21, 2020 1 hour ago, Knot Me... maybe said: If you have a real good charger you'll be fine, most these days are smarter than the users. We've been told this morning we can do short do not leave the circuit flights to keep currency but no more. But my medical fell off 3 weeks ago, bum! Automatic extension of medicals and BFR's til 24th June is in place Quote Link to post Share on other sites
mcp 36 Posted April 21, 2020 Share Posted April 21, 2020 19 minutes ago, Island Time said: In my experience though, I've seen batts prematurely die with this regime - over years though, not months. I'm not sure why this is. No temperature compensation in a hot boat would do that. Quote Link to post Share on other sites
Fogg 427 Posted April 21, 2020 Share Posted April 21, 2020 I’ve been plugged into shore power & charging 24/7 for years - the longest single stint being literally about 9 months whilst I was living outside NZ - and had no problems. But I was using professionally installed kit including Victron charger. I’ve had several Victron units over the years and I reckon they’re the real deal (although not cheap). 1 Quote Link to post Share on other sites
idlerboat 116 Posted April 21, 2020 Share Posted April 21, 2020 The batteries will last longer on than off. Commercial and emergency battery back up systems sit on a charger of some sort permanently . Letting the charge drop and then running it back up is hard cycling, which has a finite number in any battery system. 1 Quote Link to post Share on other sites
wheels 544 Posted April 21, 2020 Share Posted April 21, 2020 It's all a bit more complex.....as usual when it comes to batteries. Firstly, keeping a trickle charge on a battery is good. Can't go wrong with that part. But that is not the end of the story. Basically, it doesn't matter what you do, a Lead acid battery deteriorates in same way, even left fully charged. From the day the battery was born and accepted it's very first charge, the Chemical reaction that creates the Electrical energy, slowly eats away at the life of the plate. Also, once the plate voltage drops below 12.6V, the plates start to Sulphate. Trickle charging will stop sulphation from happening. Trickle charging is at a very low current and lower voltage than a normal charge voltage, so you do not have issues with a battery getting hot or boiling. BUT!!!!! Trickle charging does not mean the battery will remain in tip top health forever, being an eager slave just waiting to please the day the master switches on a load. FLA is the one battery type that needs the most maintenance. FLA's need to have the Electrolyte levels monitored and topped up when needed. Having special caps fitted to Deep cycles will aid in keeping the levels maintained for longer. But! in float charge, FLA's suffer from Stratification. This is where the denser Acid in the Electrolyte drops to the bottom leaving only water at the top of the plates. It is good practice once a month (ruffly, it's not critical to skip a month or two for some reason ) to apply an equalization charge which stirs the electrolyte up and also helps to balance charge across the cells. This is why Gel cell batteries tend to be used in remote backup power sites. They don't experience stratification of the electrolyte and thus a cheaper charger can be used. You may have noticed comments in the past about "surface charge". Trickle charging is when this issue tends to take place. A plate does not charge evenly when a current is applied. The charge starts from the surface and works its way into the depth of the plate. This is why a Battery takes time to charge. The Chemistry change has to work it's way into the depth of the plate. Sitting on a trickle charge for extended times does not mean the entire depth of the plate remains fully charged. Within the plate, the charge will start to decline and eventually the surface only holds a charge. Testing may show a fully charged battery. But if you place a load on the battery, it's charge will drop away quickly and the battery will be flat. So once a month, the battery really needs to be placed under a load for awhile to ensure the surface charge has been used up. Then the battery is placed under a full charge and once fully charged, placed under an equalisation charge. There are a few top end Chargers that do this automatically and this is where you discover why some chargers are damn expensive. They are also very clever. However, even on a tickle charge, eventually the battery will still die. The plate material slowly breaks down and the chemistry can no longer be maintained. 1 1 Quote Link to post Share on other sites
Island Time 1,313 Posted April 21, 2020 Share Posted April 21, 2020 Agreed Wheels, only thing I have to add is that the better chargers with temp sensors etc often have automatic equalisation cycle programs available. Quote Link to post Share on other sites
wheels 544 Posted April 21, 2020 Share Posted April 21, 2020 Yes absolutely. Is it worth you listing some Chargers that have all those kind of bells a Whistles IT?? Especially if you sell any of them Quote Link to post Share on other sites
Island Time 1,313 Posted April 22, 2020 Share Posted April 22, 2020 The victron multiplus units can do this, if the firmware is new enough. Yep, I sell various models that can do this.... Quote Link to post Share on other sites
bigal.nz 62 Posted April 25, 2020 Share Posted April 25, 2020 On 21/04/2020 at 12:41 PM, Deep Purple said: Automatic extension of medicals and BFR's til 24th June is in place How do you lot afford a plane and a boat? Quote Link to post Share on other sites
Deep Purple 530 Posted April 25, 2020 Share Posted April 25, 2020 15 minutes ago, bigal.nz said: How do you lot afford a plane and a boat? I don't have Sky 1 1 Quote Link to post Share on other sites
wheels 544 Posted April 25, 2020 Share Posted April 25, 2020 He runs behind a Taxi instead of a Bus 1 Quote Link to post Share on other sites
chariot 244 Posted April 26, 2020 Share Posted April 26, 2020 15 hours ago, Deep Purple said: I don't have Sky Who needs sky with a view like you have. Quote Link to post Share on other sites
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