Page 1 of 2 12 LastLast
Results 1 to 10 of 17
  1. #1
    Join Date
    Aug 2002
    Posts
    41

    Default \"Pulsing\" Battery Charger

    I have a 10+ years old battery charger - Tecsup 24V 40A - installed. But alas no manuals, specifications etc. It appears to be a multi stage charger. When charging from the mains, everything is fine until it tries to switch to the lowest stage which I assume is a trickle charge. The charger then "pulses" (approx. 2x a second) as it tries to switch down - the last red indicator flashes on and off. This does not happen when charging from the generator. The only difference between the generator and the mains is that the generator is not earthed into the boat's common ground.

    Before I spend lots of money on a replacement charger - simpler than trying to repair an out of date old fashioned charger, any ideas on what the problem might be?




  2. #2
    VMALLOWS is offline Registered User
    Location : Emsworth, Chichester Harbour, UK
    Join Date
    Oct 2001
    Posts
    387

    Default Re: \"Pulsing\" Battery Charger

    I assume the charger is 'new-to-you', and not that its behaviour has suddenly changed.

    The pulsing may be the deliberate way in which it reduces the charge (mobile phone chargers work that way once the battery is fully charged). Have you measured the voltage across the battery when the charger is in pulsing mode? If it has reduced to a lower figure (around 14v) then it is probably working as intended.

    I cannot explain the difference when on the generator......can only guess the AC input to the charger is lower (and not pure sine-wave) and the charger is never reaching its switch-over point.


  3. #3
    Join Date
    Aug 2002
    Posts
    41

    Default Re: \"Pulsing\" Battery Charger

    The battery charger is the original one fitted at new - 1992. I bought the boat some 4 years ago. The problem did occurr once or twice only some time back and I thought nothing of it. However, after the boat was out of the water for a couple of months six months ago, it became a persistent feature immediately on return to the water. Had had some work done on the gearbox and prop shaft but do not think that this is inter-related in any way. Previously, I have rewired the batteries, installed a new distribution board, installed a dedicated DC/DC converter to run all 12V equipment, upgraded the alternator and fitted an ADVERC controller, replaced the instruments and autopilot, overhauled the windlass and main in-mast furler, etc. No problems!

    I am currently off the boat and thus cannot remember exact voltages. I have tried recharging at different battery voltages down to as low as 23.6V. After charging at 27.6 volts, the house bank voltage rapidly reduces to 25.6 where it stays before then reducing further. Although "apparently fully charged", the voltage falls quite quickly with a fairly light load. The engine bank is fine and holds its voltage well. The house batteries are 2 plus years old whereas the engine bank is at least 5! When charged from the alternator (with the Adverc controller) the batteries appear to hold a much higher charge and do not need to be recharged for some while longer. The Adverc charges at 28.4 volts - I think it has been set for GEL batteries whereas mine are sealed maintenance free. Any idea how to reset the ADVERC?

    I have looked for a "leak" but have been unable to detect one. The ammeter shows no current draw. Mind you it only reads to 1 decimal point! It is shunted on the negative between the bus (all DC equipment have separate negatives) and the common ground with the AC circuits. I have also measured for current draw at various different points on both positives and negatives from the batteries and elsewhere with a digital clamp meter but have found nothing!

    I don't know whether this throws more light on the matter or just confuses.

    Grateful for your input and assistance.

    Regards


  4. #4
    VMALLOWS is offline Registered User
    Location : Emsworth, Chichester Harbour, UK
    Join Date
    Oct 2001
    Posts
    387

    Default Re: \"Pulsing\" Battery Charger

    If the charging voltages you quote are correct, they're all far too low and your batteries are probably never being adequately charged. How long are you charging for??

    27.6v is the float voltage to maintain a battery indefinately that has already been fully charged. At 23.6v you would be maintaining the battery in a near-discharged state. Even 28.4v from the Adverc is really only a 'maintain' level (equivalent to the charge voltage on a car). It would takes days to get the battery anywhere near charged. All these voltages must be measured at the battery terminals.......not the charger output.

    Are the batteries open-vented?......can you check the SG with a hydrometer?

    Unfortunately I suspect your domestic (house) batteries have 'had-it'. The starter battery(s) get very little use and probably manage to just-about recharge themselves.


  5. #5
    Join Date
    Aug 2002
    Posts
    41

    Default Re: \"Pulsing\" Battery Charger

    Normally only takes ½ to ¾ of an hour for the charger to get down to the float charge! Under engine can be charging for ¾ of an hour upto 4 or 5 hours. Never any problem there!

    The voltmeter reads from the panel for the house bank and from the battery terminals for the engine bank.

    Batteries are sealed low maintenance lead acid! Can’t get at ‘em to measure the SG.

    I will only be back aboard in mid October. If it is the batteries that are the problem – although this doesn’t explain why the “pulsing” doesn’t occur using the generator – I will run some more checks as well as recording voltages - at the batteries - and if agreeable to you will get back to you directly. It may be that I have two problems, one relating to the charger and the other spent batteries.

    Many thanks –again - for advice and guidance. If you have any other thoughts, ideas or suggestions on additional checks, these would be greatly appreciated.



  6. #6
    Guest

    Default Re: \"Pulsing\" Battery Charger

    Many chargers in such as Radio Control Models etc. have a pulsing style .... basically being a 12v 0r higher and pulsing the charge to reduce it to the required levels even as low as the 1.5v required for Glow-plug igniters etc.

    I have seen an old battery charger exhibit the same, but that was an old one my father had !! As another postee has said ... check the voltage as it si probably reached nera charged state and is now just keeping it topped up ....


  7. #7
    Join Date
    Aug 2002
    Posts
    41

    Default Re: \"Pulsing\" Battery Charger

    The "pulsing" is not a natural state for this charger - and it also affects other AC equipment. The AC lights also "pulse"! As mentioned before, I will investigate further on my return to the boat next month and will measure voltages at the terminals. I will also try and check the state of the batteries to see if they have had it!

    Thanks again for input, All greatly appreciated


  8. #8
    Join Date
    Sep 2001
    Posts
    18,505

    Default Re: \"Pulsing\" Battery Charger

    This sounds more like a shorepower problem, than a boat one, especially as you mention the lights and the fact that it doesn't happen on genny. Could you get the marina to check there supply?

    If I agreed with you we'd both be wrong.

  9. #9
    VMALLOWS is offline Registered User
    Location : Emsworth, Chichester Harbour, UK
    Join Date
    Oct 2001
    Posts
    387

    Default Re: \"Pulsing\" Battery Charger

    OK Hutch. Look forward to your further input in October. This one is quite intriguing. As Colin comments, it is looking as if it may be partially related to the shore power (a very high resistance feed? .. a faulty protection device?).


  10. #10
    Join Date
    Aug 2002
    Posts
    41

    Default Re: \"Pulsing\" Battery Charger

    Thanks for all the input! Given me a lot to think about - and to follow up when I am back aboard next month. Hadn't considered the possibility of a shore power problem. Thanks for that thought, Colin. Marinas in Thailand are renowned for not having properly earthed supply!

    Watch this space!


Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •