snigsnig Posted March 29, 2015 Report Share Posted March 29, 2015 Hi guys I recently replaced 3 x 110ah batteries for my domestics with 3 x 135ah, but now the alternator barely seems to be charging the battery bank at all. I have a Beta 1903 with twin alts - could the one charging the domestic bank now be too small (but would it stop working almost completely this way??) or is there something else I'm overlooking. Ran the engine for a couple of hours today but stored power ran out within half an hour or so. The same batteries had previously lasted 2.5 days after a full charge from shoreline. Thanks for any help! Neil Link to comment Share on other sites More sharing options...
mrsmelly Posted March 29, 2015 Report Share Posted March 29, 2015 Hi guys I recently replaced 3 x 110ah batteries for my domestics with 3 x 135ah, but now the alternator barely seems to be charging the battery bank at all. I have a Beta 1903 with twin alts - could the one charging the domestic bank now be too small (but would it stop working almost completely this way??) or is there something else I'm overlooking. Ran the engine for a couple of hours today but stored power ran out within half an hour or so. The same batteries had previously lasted 2.5 days after a full charge from shoreline. Thanks for any help! Neil Hi Neil Do you have any kind of battery monitoring system to refer to such as victron bm or Nasa or ampmeter? Tim Link to comment Share on other sites More sharing options...
snigsnig Posted March 29, 2015 Author Report Share Posted March 29, 2015 Nope, nothing! N Link to comment Share on other sites More sharing options...
mrsmelly Posted March 29, 2015 Report Share Posted March 29, 2015 Nope, nothing! N Well I am not the best at lectrics but your 1903 will easily charge the batteries despite the slightly larger capacities. I had a 1903 with standard set up that easily did more batts than you have. You need to check what the alternator is putting out or you will have nowhere to start with your problem. Some leccy boff will be along soon but as aliveaboard of long standing I must say some monitoring device is just about essential. Cheers Tim Link to comment Share on other sites More sharing options...
Arthur Brown Posted March 29, 2015 Report Share Posted March 29, 2015 (edited) LOTS more info needed! Battery actual volts before charging, current during charge, volts during charge. Have you checked that the connections in the charging circuit are good and clean and tight. Has this situation only started since the batteries were changed. However you should only need to replace the power/energy used from the batteries, but a full charge is likely to be a bit longer than before. Edited March 29, 2015 by Arthur Brown Link to comment Share on other sites More sharing options...
snigsnig Posted March 29, 2015 Author Report Share Posted March 29, 2015 Cheers Tim. I've really only just got around to starting to sort my battery bank, so thanks for your advice. I did assume the alternator could cope fine, so hoping I've just go a loose wire! Neil .... typing from a rapidly dimming cabin LOTS more info needed! Battery actual volts before charging, current during charge, volts during charge. Have you checked that the connections in the charging circuit are good and clean and tight. Has this situation only started since the batteries were changed. Only started since changing the batteries, yes. I have no way of giving any exact numbers and figures, just welcoming any obvious things I may have missed... the first being checking again for loose connections first thing tomorrow! Thanks. N Link to comment Share on other sites More sharing options...
nicknorman Posted March 29, 2015 Report Share Posted March 29, 2015 Neil, as I often say on this forum, electricity is invisible and so you need adequate test/monitoring equipment to know what is going on. When everything is working, that is all fine and dandy, but when it isn't it is like trying to fix your engine with the lights out - you are just stumbling around in the dark UNLESS you have proper test/monitoring equipment. Anyway, the good news is that there is nothing intrinsically wrong with your setup - the engine / alternators should be able to charge the batteries quite happily, so there is clearly a fault that needs fixing. How to find that fault? Well, you need .... (Fill in the dots!) Link to comment Share on other sites More sharing options...
Alan Saunders Posted March 29, 2015 Report Share Posted March 29, 2015 Chances are that your 'new 135Ah batteries were supplied at <80% SOC and already 'sulphated'; ideally you would have immediately recharged them to 100%. The cure, apparently, is 15.5V for a few hours but few of us can achieve this. After I totally discharged my new 'leisure' batteries several times, due to a failed alternator, a long (12h!) charge/cruise seems to have recovered much of their capacity but I expect to replace them sooner than annually. Good luck, Alan Link to comment Share on other sites More sharing options...
bottle Posted March 30, 2015 Report Share Posted March 30, 2015 Hi guys I recently replaced 3 x 110ah batteries for my domestics with 3 x 135ah,No problem there but now the alternator barely seems to be charging the battery bank at all. I have a Beta 1903 with twin alts - could the one charging the domestic bank now be too small No (but would it stop working almost completely this way??) or is there something else I'm overlooking.Probably Ran the engine for a couple of hours today but stored power ran out within half an hour or so.Batteries were not charged and are now completely flat and in a bad condition to be left in The same batteries had previously lasted 2.5 days after a full charge from shoreline. Thanks for any help! Neil Check and double check all connections are in the correct position, clean and tight. My thought is it is a bad/missing connection, check the back of the alternator a wire may have become disconnected even though you never went there when changing the batteries. Check any multi connectors, pull apart and check they are clean and re-connect, again may have been moved when fitting batteries. Then it's into meters and checking the alternator is working. Link to comment Share on other sites More sharing options...
Keeping Up Posted March 30, 2015 Report Share Posted March 30, 2015 You could try giving the battery isolator switch a waggle (when the engine is not running) because some types are notoriously unreliable. Link to comment Share on other sites More sharing options...
Sir Nibble Posted March 30, 2015 Report Share Posted March 30, 2015 Is there a possibility the battery connections may have been reversed however briefly? Link to comment Share on other sites More sharing options...
snigsnig Posted April 8, 2015 Author Report Share Posted April 8, 2015 (edited) Thanks everyone. Had a mooch, bit of a fumble, gave things a waggle, and lo and behold it started charging fine the following day. All connections seem tight and clean, but she's quite an old boat so something must have just needed a bit of a nudge! Edited April 8, 2015 by snigsnig Link to comment Share on other sites More sharing options...
Theo Posted April 8, 2015 Report Share Posted April 8, 2015 (edited) You could try giving the battery isolator switch a waggle (when the engine is not running) because some types are notoriously unreliable. Really important that you do this with the engine stopped. With the engine running you are certain to blow the alternator regulator. N Edited April 8, 2015 by Theo fat fingers Link to comment Share on other sites More sharing options...
pete.i Posted April 8, 2015 Report Share Posted April 8, 2015 Really important that you do this with the engine stopped. With the engine running you are certain to blow the alternator regulator. N Yep need to re-iterate this. I blew my alternator regulator because my starter battery isolator switch had gone intermittent which meant it occasionally went open circuit. If I hadn't got volt meters permanently connected to each set of batteries I wouldn't have known and quite possibly could have blown up a battery. The voltage went up to 16.5 volts across the battery terminals by the time I actually noticed it. Link to comment Share on other sites More sharing options...
Theo Posted April 12, 2015 Report Share Posted April 12, 2015 That's interesting. I was under the impression that regs normally failed open circuit so that the alternator stopped working rather than the opposite. N Link to comment Share on other sites More sharing options...
Tony Brooks Posted April 13, 2015 Report Share Posted April 13, 2015 That's interesting. I was under the impression that regs normally failed open circuit so that the alternator stopped working rather than the opposite. N It need not be the regulator that failed. If the voltage surge blew one or two field diodes open circuit you are likely to get a higher charging voltage. Link to comment Share on other sites More sharing options...
Phil Ambrose Posted April 13, 2015 Report Share Posted April 13, 2015 Cor! this boating lark is a bit if a worry, random things going wrong etc. Glad your problem is sorted, now you just need to find the culprit and then get a decent monitoring system. Phil Link to comment Share on other sites More sharing options...
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