Ring rsdc30 as B2B only

Londonboii

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42
I have a ring rsdc30 and currently use it as a solar controller and B2B. However I want to add more panels to my roof which will be more that it can take so I have bought a victron solar controller.

I would rather not have to spend more money buying a sterling so I was hoping to leave the Ring connected and use it to charge the batteries when driving only.

Are there any issues with using it solely as a B2B alongside the victron? Would the 2 devices clash at all if I was say driving on a sunny day or any other issues that may come up?
 

Edina

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I did the same and tbe ring is working fine as a b2b only. My solar controller is the Victron smart mppt.
 

Okta

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532
I do not have one but out of interest googled the instruction manual. I noticed that there is a setting to give priority to solar, which can be turned on and off. Having disconnected the the solar panels I would expect the B2B to work fine but you might want to have the solar priority set to off, to save it looking for something that is not there.
 

Edina

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25,629
I do not have one but out of interest googled the instruction manual. I noticed that there is a setting to give priority to solar, which can be turned on and off. Having disconnected the the solar panels I would expect the B2B to work fine but you might want to have the solar priority set to off, to save it looking for something that is not there.
There is really no point in ever setting solar priority on in a setup like mine, because the alternator will always give more than the panels.
 

CriftinsCampers

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59
It works perfectly ok in either isolated role.

The give priority to Solar setting is there to stop the thing going into a hysterical loop when using a a chassis battery trickle charger like the Sterling BM12123.

Without using that setting when the chassis battery rises above the B2B cut in threshold the charger can switch over to B2B mode until the voltage drops below the threshold, this counter productive hence the setting.

It's a shame the Ring isn't a bit more intelligent it also a shame there is not a remote display for it either as its still a pretty good value bit of kit with a very unique feature, very few combined Mppt/B2B units support more than around 25-30Voc the ring supports 50Voc and that the primary reason I bought mine it allows virtually every size panel on the market to be used.


@Londonboii

The Ring is rated at 30A output, that max current is only ever drawn when a battery is heavily discharged and even then during a relatively very short period of time during the bulk charge phase.
Which for a typical 12v lead acid battery peaks at around 14-14.6V hence the ring can support around 440W of solar to achieve that output.

In reality Solar charger rarely reaches max current I would be almost inclined to say never!
A 440W array flat on a roof will never produce 440W
Even if it could on a bright sunny day in midsummer a heavily discharged battery bank will have probably completed the highest current part of the bulk charge long before mid day.

Hence imho you could probably hang 600-1000W off the thing via say a 25-30A fuse on the PV input (just to be safe) and it would work perfectly ok and well within it capabilities.

In fact this technique works extremely well late summer through to early spring where PV is not particularly good but is the time of year when we need every bit we can get.

The exception to the above suggestion is if you do something like run a 2kw kettle via an inverter midday with the sun directly overhead.

Then that massive hit on the batteries might knock the voltage down to the point the controller will switch to bulk charge and could either pop the PV input fuse or show error E3 but in all honesty at that time of year your typical single 300W panel is usually more than enough.
 

wildebus

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3,138
There is really no point in ever setting solar priority on in a setup like mine, because the alternator will always give more than the panels.
Never looked at the Ring unit so can't talk about that, but there are some Combo units that allow both Solar and B2B functions to operate in partnership for maximum effect. The Redarc BCDC Dual is such a unit ... it prioritisies charging from the PV Panels and makes up the difference with the B2B side of the unit upto the current capability of the unit or charging demand from the battery (whichever is less) .
The idea being that the solar input is free and the lower the demand on the alternator you can get away with the better (fuel consumption).

How much difference in reality reducing the alternator demand makes is hard to be sure but the concept is sound.
 

CriftinsCampers

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59
Yep the Renogy Dcc50s works in a similar way max is 50A from the alternator unless it detects any pv input then it derates to 25A from the alternator plus whatever is coming via PV sad thing about the unit is the low max voc at 25v so limited to three or four 150-175w panels wired in parallel max
 
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