Chrisgriff Posted June 6, 2018 Report Share Posted June 6, 2018 Hi fellow boaters. been on my boat for over a year now. we took her out for a trip to bath the other day and moored up for one evening then came back to Bristol. On the way to bath our battery seemed fine & fully charged. but once we arrive about 3 hours later the battery was dead. Then on the way back to Bristol the battery just didn't seem to be charging at all. since we have been back and have connected back to shore power our inverter charger seems to be constantly on battery charge mode...... Which it never used to do all the time. I dont really understand why when we are on shore power that the batteries are constantly trying to charge? Does anyone one think they have any clues to this problem? Knackered batteries? cheers, chris Link to comment Share on other sites More sharing options...
Robbo Posted June 6, 2018 Report Share Posted June 6, 2018 Do you have a amp meter of some kind? This will help in diagnosing the issue. Link to comment Share on other sites More sharing options...
Chrisgriff Posted June 6, 2018 Author Report Share Posted June 6, 2018 Hey! yes it's reading at 13.3 and the lights on the inverter say it's: -charger on on float charge mode - shore power online, battery charger active. cgeers Link to comment Share on other sites More sharing options...
Robbo Posted June 6, 2018 Report Share Posted June 6, 2018 (edited) 20 minutes ago, Chrisgriff said: Hey! yes it's reading at 13.3 and the lights on the inverter say it's: -charger on on float charge mode - shore power online, battery charger active. cgeers When off shore power, take a note of what it’s saying when engine not running, and when engine running anything more than idle. Also take note of the battery voltage. Basically trying to see if you have something on like a immersion running from your inverter and/or if your alternator is working. also check the temperature of each battery, if one it warmer than the others (when charging) it may have a short dragging the others down. If one is hot stop charging immediately. note is 13.3 the amps or the voltage? Edited June 6, 2018 by Robbo Link to comment Share on other sites More sharing options...
nicknorman Posted June 6, 2018 Report Share Posted June 6, 2018 Can you specify which inverter charger you have? Normally when an inverter charger (Combi) is plugged into the mains, the battery charger is on constantly and after a while will be in float mode. So the inverter lights seem normal to me. The figure you quote is I suspect the voltage, not the current. It sounds like your boat’s alternator isn't charging. With the shore power unplugged and the engine running, what is the voltage? It also sounds like you batteries have very low capacity, but let’s think about the charging thing first! Link to comment Share on other sites More sharing options...
Chrisgriff Posted June 6, 2018 Author Report Share Posted June 6, 2018 Shore power off : 13.2 Shore power off & engine on : 13.9 Will attach picture of step up. also..... Just found a lead which had dropped down the back of our electric board with this note on: "This wire must be removed when the domestic battery positive lead has been connected to the terminal post. WARNING: do not run engine without this wire in place or without the domestic battery positive lead connected otherwise alternator damage will occur" we we have never seen this lead before until now........ Got a feeling that's why we have had problems since our outing to bath? cheers Link to comment Share on other sites More sharing options...
nicknorman Posted June 6, 2018 Report Share Posted June 6, 2018 (edited) 13.9 is low for engine running. Possibly an old style alternator with a low regulation voltage, or a more modern alternator that is partially damaged. It will never be much good for charging batteries whilst cruising. However that doesn’t explain why the batteries went flat whilst you are cruising. When you have the opportunity, try unplugging the shore power, keeping an idea of what is being powered, and recording the voltage from time to time, along with the time. Plug the shore power in before the voltage reaches 12v. That way, we can get an idea of whether the batteries are goosed or not. Edited June 6, 2018 by nicknorman 1 Link to comment Share on other sites More sharing options...
Chrisgriff Posted June 6, 2018 Author Report Share Posted June 6, 2018 Ok perfect. thanks for all the information. when crushing the battery didn't die completely..... The main lights in the boat remained on but the voltage was very low.... All other electrics turned off. Also the boat is only 10 years old so have a feeling it has a more modern alternator? So have a feeling that's probably damaged and the batteries don't hold much power! chris Link to comment Share on other sites More sharing options...
nicknorman Posted June 6, 2018 Report Share Posted June 6, 2018 6 minutes ago, Chrisgriff said: Ok perfect. thanks for all the information. when crushing the battery didn't die completely..... The main lights in the boat remained on but the voltage was very low.... All other electrics turned off. Also the boat is only 10 years old so have a feeling it has a more modern alternator? So have a feeling that's probably damaged and the batteries don't hold much power! chris Yes that could well be the case. Do you know how old the batteries are? But the important thing is to fix the alternator charging issue before getting new batteries. Failing to properly charge batteries is the fast way to kill them! Link to comment Share on other sites More sharing options...
Chrisgriff Posted June 6, 2018 Author Report Share Posted June 6, 2018 I'm not sure how old the batteries are but for a guess I don't think they are that old. i just looked at the alternator and it's a Barrus alternator. i understand that the inverter is important for charging th battery when engine is running but what j don't understand is why the battery is constantly charging when we are hooked up to shore power? Does the current have to still run through the inverter? sorry for all the questions!! Electrics isn't my strong point! Link to comment Share on other sites More sharing options...
Tony Brooks Posted June 6, 2018 Report Share Posted June 6, 2018 3 minutes ago, Chrisgriff said: I'm not sure how old the batteries are but for a guess I don't think they are that old. i just looked at the alternator and it's a Barrus alternator. i understand that the inverter is important for charging th battery when engine is running but what j don't understand is why the battery is constantly charging when we are hooked up to shore power? Does the current have to still run through the inverter? sorry for all the questions!! Electrics isn't my strong point! Only if you have a Travel Power mains generator on the engine and even then its the battery charger function that is important. I am sure that 13.3 is a voltage reading and not Amps and as Nick says it implies the alternator is in trouble. Perhaps the first thing to do is to remove all the battery terminals, clean them to bright metal, including the posts, and refit. Corroded battery cnnections can "fail" while in use Link to comment Share on other sites More sharing options...
Chrisgriff Posted June 6, 2018 Author Report Share Posted June 6, 2018 Ok thanks for that. so in guessing that the batteries just can't charge properly even when engine off & connected to shore power which is why the inverter charger is constantly trying to charge the batteries...... so must be the alternator. c Link to comment Share on other sites More sharing options...
Chrisgriff Posted June 6, 2018 Author Report Share Posted June 6, 2018 Any info on this blue wire with the note? it also mentions this in the Barrus shire engine manual..... this is has never been connected, and was not connected when we went for a cruise a couple weeks ago....... Seems odd that I have to attach this lead every time I want to go for a cruise..... c Link to comment Share on other sites More sharing options...
Richard10002 Posted June 6, 2018 Report Share Posted June 6, 2018 I have the same/similar Sterling inverter charger, (mine is a Pro Combi S 2500W). When shore power is on, the battery charger function is on, unless I switch the inverter charger off. If I was connected to shore power 24/7, most of the time the inverter charger would be charging in float mode... so being in float mode is normal, and not a problem. In fact, the Sterling actually goes into float far too soon for my batteries, and I have to keep resetting it to charge in absorption mode, until the tail current is low enough, and the batteries are full. I suspect you dont have a battery monitor, and no facility to monitor Amps being drawn by the batteries. Link to comment Share on other sites More sharing options...
Alan de Enfield Posted June 6, 2018 Report Share Posted June 6, 2018 7 minutes ago, Richard10002 said: When shore power is on, the battery charger function is on, unless I switch the inverter charger off. If I was connected to shore power 24/7, most of the time the inverter charger would be charging in float mode... so being in float mode is normal, and not a problem. In fact, the Sterling actually goes into float far too soon for my batteries, and I have to keep resetting it to charge in absorption mode, until the tail current is low enough, and the batteries are full. I'm guessing that whilst the OP understands the meaning of the individual words, when they are strung together they become meaningless. Link to comment Share on other sites More sharing options...
Chrisgriff Posted June 6, 2018 Author Report Share Posted June 6, 2018 Thanks for your reply. it just seems to be always on float charge mode and the fan never stops! when on shore power (which is 99% of the time) we leave it on power saver auto. if we turn the inverter off then all electrics (fridge, plug sockets) except for the main lights turn off. if we have it as power saver mode then it just does the same as auto, and just stays on float charge mode.... Link to comment Share on other sites More sharing options...
nicknorman Posted June 6, 2018 Report Share Posted June 6, 2018 (edited) 1 hour ago, Chrisgriff said: I'm not sure how old the batteries are but for a guess I don't think they are that old. i just looked at the alternator and it's a Barrus alternator. i understand that the inverter is important for charging th battery when engine is running but what j don't understand is why the battery is constantly charging when we are hooked up to shore power? Does the current have to still run through the inverter? sorry for all the questions!! Electrics isn't my strong point! When on shore power the inverter charger passes the shore power through to the boat, so your sockets etc are powered directly by shore power. The battery charger side of things is designed to be on permanently when on shore power. As the battery becomes fully charged the current falls to near zero. So it isn’t actually doing much nor using much power. What it is doing is keeping the batteries fully topped up (there is a small degree of self discharge over time) and also running whatever 12v services that are being used on the boat. when you turn the Combi off, it will shut off the pass-through of mains shore power as well as the charger. So leave it on, this is how it is designed to be used! pretty sure the power saver function is only relevant when the shore power isn’t plugged in. It determines how the inverter behaves when there is no load on it. Edited June 6, 2018 by nicknorman Link to comment Share on other sites More sharing options...
Richard10002 Posted June 6, 2018 Report Share Posted June 6, 2018 11 minutes ago, Alan de Enfield said: I'm guessing that whilst the OP understands the meaning of the individual words, when they are strung together they become meaningless. perhaps, but as he sees them more, does a bit of googling, and has the odd "light bulb" moment, things will become clearer.... Link to comment Share on other sites More sharing options...
George and Dragon Posted June 6, 2018 Report Share Posted June 6, 2018 29 minutes ago, Alan de Enfield said: I'm guessing that whilst the OP understands the meaning of the individual words, when they are strung together they become meaningless. That's a problem I sometimes encounter Link to comment Share on other sites More sharing options...
Dr Bob Posted June 7, 2018 Report Share Posted June 7, 2018 (edited) As with a lot of these charging threads, the is a lot of guessing going on as we don't know anything about currents, or for the OP - Amps. The best answer is to get a battery monitor or at least a D.C. Clamp meter so we know how it's charging. Looking at the story so far, what do we know? The combi is working fine in float mode giving 13.3v when on shore power, just as it does. It therefore suggests the batteries are full ish ....as it is on float. But why is the fan running all the time. My chargers aren't running a fan on float. The blue wire in post 13 sounds a red herring as the combi is working so should be connected to the battery +ve. Off shore power with engine running we have 13.9v. That's too low for best charging but will get the batteries up to reasonable PROVIDING the Amps are high enough. We ran our boat for 4 months with a charge voltage of 13.9v before we put a sterling AtoB on and that would not account for a sudden death problem unless the batteries were totally shot. It sounds to me that there could be a number of options. 1) Tony's solution of cleaning terminals above. 2) You had some electrical stuff running in the trip to Bath, viz immersion heater, coffee machine that drained the batteries so this is a one off and your batteries are now back to full 3) Your batteries are heavily sulphated ( i.e. Shot) due to the low charge voltage over a period of years and now have little capacity so 3 hrs of light use knackered them. You can check this easily by doing what Nick said in post 7. Take it off shore power and run something that puts around 10A load. (You didn't say how many batteries you have and what capacity- useful for us to know) or just run stuff and report back the voltage over a 5-10 hr period. If the capacity is down, this will show up. As Nick says, as voltage drops, put it back on shore power before it gets to 12.1 V If it is (3), then get a battery monitor and sort out the charging before you buy new batteries. A DC clamp meter is circa £35. Edited June 7, 2018 by Dr Bob Link to comment Share on other sites More sharing options...
Richard10002 Posted June 7, 2018 Report Share Posted June 7, 2018 Definitely get a battery monitor! Not a Smartgauge in this particular set of circumstances..... I have a NASA BM2, which tells me voltage and how many amps are flowing at any particular time, and how many amp hours have been used since resetting the counter. Link to comment Share on other sites More sharing options...
MtB Posted June 7, 2018 Report Share Posted June 7, 2018 12 hours ago, nicknorman said: 13.9 is low for engine running. Possibly an old style alternator with a low regulation voltage, or a more modern alternator that is partially damaged. 13.9 is an odd voltage. I'm fairly sure when I had an alternator with an expired diode it was giving me 12.9v on the DVM. I'd say this is down to a 14.4v regulator and several not-very-good connections between it and the batteries. Depending that is, on where/what that volt meter has been connected to! (Can anyone here confirm what voltage an alternator with a goosed diode generally chucks out?) Link to comment Share on other sites More sharing options...
nicknorman Posted June 7, 2018 Report Share Posted June 7, 2018 55 minutes ago, Mike the Boilerman said: 13.9 is an odd voltage. I'm fairly sure when I had an alternator with an expired diode it was giving me 12.9v on the DVM. I'd say this is down to a 14.4v regulator and several not-very-good connections between it and the batteries. Depending that is, on where/what that volt meter has been connected to! (Can anyone here confirm what voltage an alternator with a goosed diode generally chucks out?) It’s a good question and I’m not sure, but the other thing is that I’m sure it varies a lot with load. The OP’s test took fully charged batteries off a mains charger and onto the alternator, so the charge current at 13.9v would have been near zero. If the batteries were at 50% SoC, perhaps the voltage would have been closer to 12.9v. Link to comment Share on other sites More sharing options...
Chrisgriff Posted June 7, 2018 Author Report Share Posted June 7, 2018 "3) Your batteries are heavily sulphated ( i.e. Shot) due to the low charge voltage over a period of years and now have little capacity so 3 hrs of light use knackered them. You can check this easily by doing what Nick said in post 7. Take it off shore power and run something that puts around 10A load. (You didn't say how many batteries you have and what capacity- useful for us to know) or just run stuff and report back the voltage over a 5-10 hr period. If the capacity is down, this will show up. As Nick says, as voltage drops, put it back on shore power before it gets to 12.1 V" thanks gor this...... I will check when back in the boat this evening & report back! Link to comment Share on other sites More sharing options...
cuthound Posted June 7, 2018 Report Share Posted June 7, 2018 When was the 13.9 volts measured? If the batteries were very flat, the alternator may not have come out of current limitation, and thus only be giving 13.9 volts. After checking for loose or corroded connections, the OP needs to measure the battery voltage with the engine running immediately after the charge has been switched off when the charger has been in float for a while. Only then can we decide if the alternator is faulty. Link to comment Share on other sites More sharing options...
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