Truma Solar Dual Battery Charger SDC 10/20

Grammarian47
Grammarian47 Forum Participant Posts: 14
edited April 2020 in Motorhomes #1


I bought a new Motorhome (Autoquest 175) last year (breaking my heart to see it sat unused on the drive).
It has a 100w roof mounted solar panel with a Truma controller.
It enables me to set the type of battery and the percentage charge that goes to the battery if more than one battery fitted. (I only have one battery, (liquid), so it automatically sends all the solar charge to that).I understand the first 2 settings and have set them for the battery type ie liquid, and charge allocation. The 3rd setting allows me to set a PWM charging frequency (whatever that means) of 25Hz (preset), 50Hz or 100Hz. How do I find out which of these PWM settings to use as the handbook is not helpful on this? Any advice you can offer will be very much appreciated.

Comments

  • young thomas
    young thomas Forum Participant Posts: 11,356
    1000 Comments
    edited April 2020 #2

    here you go....the exaxt same question on Motorhome Fun

    it didnt help me much...

    as it happens, i was looking at theis very controller (different forum) and i wouldnt have a clue as to the PWM setting...

    id leave it as the default.

  • young thomas
    young thomas Forum Participant Posts: 11,356
    1000 Comments
    edited April 2020 #4

    i read those but, while it showed how to change the setting,  it didnt show why you would need to.

  • hitchglitch
    hitchglitch Forum Participant Posts: 3,007
    1000 Comments
    edited April 2020 #5

    A PWM produces pulses which may interfere with other devices such as a radio etc. If this happens, change the frequency.  I am curious that you say that you have only one battery. Usually motorhomes have a starter battery for the engine electrics and one or more leisure batteries. The charger can then be set for either battery (cab or habitation) or both. 
    I am not sure about the setting for gel or liquid. A “sealed” battery could be gel or liquid but has an important different charging regime to a flooded liquid battery. Most domestic chargers have a “sealed” setting not a gel/liquid setting as this could be ambiguous.

  • young thomas
    young thomas Forum Participant Posts: 11,356
    1000 Comments
    edited April 2020 #6

    thanks, Hitch...that makes sensesmile

  • BrianDicks
    BrianDicks Forum Participant Posts: 1
    edited July 2020 #7

    The manual is not on the Truma website any more. You can find it here:

     

    https://www.manualslib.com/download/1251776/Truma-Sdc-10.html

  • Summer Lightning
    Summer Lightning Forum Participant Posts: 1
    edited January 2021 #8

    I have recently purchased an Elddis185 with solar panel, it has a Truma dual battery charger but only the leisure battery connected, question, can i connect the engine battery direct to the 2nd battery connection or does it need some additional circuitary?

  • Freedom a whitebox
    Freedom a whitebox Club Member Posts: 296 ✭✭✭
    100 Comments
    edited January 2021 #9

    I have connected a fly lead to the extra terminals on the Truma controller on my caravan and connect this to my navara to keep its battery charged while it’s not in use and this has coped since the first lockdown, without any problems. 

  • DavidKlyne
    DavidKlyne Club Member Posts: 13,859 ✭✭✭
    5,000 Likes 1000 Comments Name Dropper Photogenic
    edited January 2021 #10

    Sounds a bit like my Bailey motorhome. Same controller but only connected to the leisure battery! The way I got round it was to have a Battery Master fitted which basically pushes any excess charge in the leisure battery to the cab battery. You can do what you are suggesting but the usual split is 90/10 leisure/cab and some have found the 10% not enough to keep the cab battery fully charged. Obviously you could change the ratio but the more you do that the less charge is going into the leisure battery which might no be the best idea?

    David

  • cyberyacht
    cyberyacht Forum Participant Posts: 10,218
    1000 Comments
    edited January 2021 #11

    I had a dual solar controller on previous MH. I found the 90/10 ratio worked perfectly satisfactorily. The current MH has a Batterymaster which cuts in, I think, if the voltage differential is 1v. It's OK but doesn't keep the cab battery at 100% all the time like the previous arrangement.

  • DavidKlyne
    DavidKlyne Club Member Posts: 13,859 ✭✭✭
    5,000 Likes 1000 Comments Name Dropper Photogenic
    edited January 2021 #12

    I have had the device fitted on both motorhomes and it has proved very reliable in the last 7/8 years. It obviously works whilst on EHU which I have the van connected to for at least part of the day, everyday. On my vehicle the cab battery is not charged directly from the EHU. With a solar panel, if that is all that is being relied on to keep the charge topped up, especially in weather where there is not much charge I imagine that it might struggle.  The acid test is whether the engine starts when you want it to, so far so good!!!

    David

  • PhilnShaz
    PhilnShaz Forum Participant Posts: 16
    edited January 2021 #13

    Personally I don't understand why so many people want to charge their leisure battery more than the vehicle battery as the vehicle battery usually powers things like alarms and security devices as well as backing up the radio memory, whilst the leisure battery is usually turned OFF during storage, so I have my solar charger set at 90% vehicle and 10% leisure. Unfortunately I have not been able to go to the M/H since this lockdown to check how it is doing.

     

  • cyberyacht
    cyberyacht Forum Participant Posts: 10,218
    1000 Comments
    edited January 2021 #14

    Presumably that's just to keep you going until you plug in to a site EHU. That format wouldn't work very well if you were off hook-up.

  • PhilnShaz
    PhilnShaz Forum Participant Posts: 16
    edited January 2021 #15

    True, but it's only whilst the M/H is in storage.

    When we are using the m/h I have it set to 50/50.