Understanding caravan battery charger

Baymare
Baymare Forum Participant Posts: 69
edited July 2020 in Caravans #1

Hi,

    After fitting motor mover decided to replace 75amp battery with 110amp.

Not being good with electrics I would ask how would you know if your caravan had an on board battery charging facility and more importantly how do you know it's working.

I have refurbished a coachman Amara 2001 which has a power centre but there is nothing that states battery charger.

A. How can I check it works and is charging the battery when on 240.

B. If it is not working what are good alternatives to opening up the power centre and easy to install. Or should I just take a liesure battery charger with me and charge  if and when required.

I've been at this refurb all winter and have had it for now.

Baymare

 

 

 

Comments

  • no one
    no one Forum Participant Posts: 216
    edited July 2020 #2

    A simple and quick way is to measure the voltage across the battery (12-13.3v) with a volt meter. then power up your 240v, if there is an auto charging system fitted, the battery voltage should increase, even if the battery is already charged, normally to between 14.2 and 14.5v

  • ocsid
    ocsid Forum Participant Posts: 1,395
    1000 Comments
    edited July 2020 #3

    Given it is a 2001 caravan the likelihood is that it will not have a "smart" charger, so the voltage doesn't rise to the suggested 14.2>14.5 volts.

    Whilst it may be fitted with such a charger it probably has a rudimentary power supply unit regulated to a maximum of 13.8 volts.

    This however will recharge the battery, and be a clear indication the electronics are working by lifting from a rested battery voltage of about 12.7 volts, when the EHU is connected.

    If you have not a multimeter to measure the battery volts, then if any lights are the older filament type they should get noticeably brighter as the EHU is connected, and dim a little when it is removed. Not a test with much finesse, but a pretty good basic indicator things are working.

  • Baymare
    Baymare Forum Participant Posts: 69
    edited July 2020 #4

    Hi and thanks,

    It would appear it has neither as the the little battery indicator is sitting just below 13 volts but doesn't rise when hooked up to the mains.

    Any experience of solar battery charger the appear very easy to fit on, but don't have a clue if they are any good.

     

  • KeithL
    KeithL Forum Participant Posts: 114
    edited July 2020 #5

    Have you considered something like a CTEK charger? They come in various charging capacities and also have a supply function.

    They also have a useful connection plug you leave attached to the battery and plug the charger into it, dead easy if you take the charger out of the van for security or to use elsewhere. 

  • Baymare
    Baymare Forum Participant Posts: 69
    edited July 2020 #6

    Have just read the manual and it does have a charger in the power centre.

    However, I don't know if it works my understanding is to find out I will require a volt meter to test the voltage is 13.8 at the battery when hooked up to the mains.

    Somebody gave me one years ago and it could be in my toolbox but a retired blacksmith doesn't really have the brains to use such instruments.

    If not one of these cetec things might be the answer.

    Baymare

  • EmilysDad
    EmilysDad Forum Participant Posts: 8,973
    1000 Comments
    edited July 2020 #7

    A reasonable voltage tester or multimeter can be bought for a few quid ..... obviously you can pay somewhat more for a Fluke  .... and even a retired blacksmith can be re-trained to use one. 😉 They're a handy thing to have.

  • Amesford
    Amesford Club Member Posts: 685 ✭✭✭
    500 Comments
    edited July 2020 #8

    Do a search on you tube it will show you how to use a multimeter to check your battery etc. I should think a van of that age will be fitted with a Zig unit

  • Baymare
    Baymare Forum Participant Posts: 69
    edited July 2020 #9

    Eureka I've found the thing. I'll turn on the mains and see what voltage I get at the battery I'm presuming it should be around 13.8 if the charger is working.

    If not I'm not opening that electrical power box 

  • Baymare
    Baymare Forum Participant Posts: 69
    edited July 2020 #10

    Well at least I know now that the power centre isn't charging the battery. Using the voltmeter with being hooked up to the mains I only get 12.7v at the battery. My understanding is that being hooked up I should see approximately 13.8v. I have a trickle charger I could wire in or get a solar unit as an option.

    Thanks to all any further advice is always welcome as every day is a school day.

     

     

  • ocsid
    ocsid Forum Participant Posts: 1,395
    1000 Comments
    edited July 2020 #11

    You are right in that if you are not seeing something close to 13.8 volts whilst on an EHU then the battery is not getting charged.

    With modern smart chargers you could more, and academically you would get a painfully slow charge with a little less, but I suspect no caravan charger maker ever went that route?

    Solar is brilliant as a charging means supporting off EHU camping in the summer months, but it would be very challenged to provide a comparable alternative solution to a mains powered charger/PSU.

    The solar array you would need would cost way more than simply changing out your defective charger unit.

    A trickle charger is as it is named a trickle charger, given time it will recharge the battery.

    There are companies that rework caravan chargers and do exchange units; without being rude your 2001 charger is going to be a pretty cheap and by todays standards basic unit; I would just replace it with a reworked one and move on.

  • Baymare
    Baymare Forum Participant Posts: 69
    edited July 2020 #12

    I don't mind cheap ocsid this is a refurb job, is it easy to replace the charger. If it's a unit out and unit in I could manage that but it's in a right awkward place behind the gas heater and is there anything that might give me a shock, obviously I'll disconnect the power but I'm not sure if there are capacitor things in the unit.

    Names of companies who deal with this kind of stuff would be welcome.

    And thanks for all your and everyone else's advice this refurb started as a wee protect to keep me busy but this is the last bit of the job.

     

  • hitchglitch
    hitchglitch Forum Participant Posts: 3,007
    1000 Comments
    edited July 2020 #13

    I wouldn’t recommend buying a free standing charger because you would not be able to run the 12 volt system at the same time. On older caravans the power supply was fixed at around 13.8 volts as it’s enough to keep the battery charged and yet not too high a voltage for the 12 volt system. It’s a compromise because a fixed voltage like that will not properly recharge a flat battery, it’s really for topping up. A CTek is an intelligent charger which is designed to give up to around 14.3 volts (more on pulsed mode) so is great if you want to disconnect the battery and charge it properly. This is why newer vans often offer smart chargers that take the battery off-line on EHU and give it a multistage charge.

    As suggested above, a refurbished or replacement caravan power supply is the sensible option and it will give you your dc system as well as keep the battery charged on hook-up.

  • no one
    no one Forum Participant Posts: 216
    edited July 2020 #14

    If left powered down for at least 1/2 an hour with mains and battery disconnected, any capacitance will have discharged so should be ok to play with.

  • Baymare
    Baymare Forum Participant Posts: 69
    edited July 2020 #15

    I used a mates voltmeter just to double check things. It turns out that with the battery terminals disconnected and running an extension cable from the house and connecting to the van I get a reading of 12volts at the terminals. Which is still well short of 13.8v. will this 12volts mean the battery will discharge when it's all hooked up normally.

    I knew I should have stuck in at school instead of leaving to bend metal and shoe horses😄😄.

    Either way I think I need another charger but can safely chuck my voltmeter in the bin.