My split charge relay has gone bad..

[slowcoach]

ive noticed my leisure battery not relay getting charged up any more, and have traced it to my split relay, only properly linking the batteries while i press down reasonably firmly onto the top of it with my finger once the indicator LED on it has lit, causing the clunk of the connection noise (its screwed into the engine firewall under the back seat, a nice amplifier in itself) , to tell me that the relay is closed. so its sensing the voltage at the right time, just the closing of the relay is fudged up. ive found that out with a multimeter and behaves correct with my finger pressure. doesnt seem to a be a relay earthing prob either. the model is a REDARC 100a unit, voltage sensing (off at 12.4v, on at 13.4v ish), original i think to the van.
looks roughly like this, though mine is a much older model:
http://redarc.com.au/static/files/SBI_1_Page_Spec.pdf

so was wondering if anyone can recommend for/against this one:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 430wt_1139

is it actually voltage sensing? doesnt state any volt specs for closing. does it even matter? ive a 125ah leisure batt.
thanks!!

[kevtherev]

This doesn't help but....
I opted for a very simple alternator triggered 70 amp relay cost pence from maplin and charges to 75 amphour batteries plus the starter

[Oldiebut goodie]

I've used one of those - they seem to be OK. I hear it clicking away as the sun appears from behind a cloud and the solar panel charges. I have never bothered to check what voltage they actually switch at though. The only drawback with them is the fact that you cannot adjust the switching voltage (but then not everyone needs to do so).
Just ensure that your wiring and fuse is up to using 100A.

[slowcoach]

thanks guys, the wiring does look pretty chunk, i dont have an ammeter/multimeter that will measure that high, would be interesting to see whats coming out of the alternator besides voltage.

i get about 14.1v from it before the leisure batt is in the loop. Once that is in the loop, it drops to about 13.8, at idle speed. but this will vary depending on how flat each battery is and what the alt decides to put out, right?

[Oldiebut goodie]

Yep, your voltages are OK.