Truma Solar Dual Battery Charger SDC 10/20

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.

https://www.truma.com/web/downloadcenter/files/truma-solar-dual-battery-charger-operating-instructions-2019-uk-en.pdf

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

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.

thanks, Hitch...that makes sense

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

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?

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. 

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

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.