Leisure battery and split charge relay

[Eratosthenes]

We have a year 2000 V6 and 5 or 6 years ago fitted a Rooster split charge unit and a Leisure battery. The LB hasn't really had much use over the years.
The 2 connections to the split charge unit are from fuse box locations 1 and 8 (cabin lights and mirrors radio and cigar lighter sockets). I noticed when retracting the mirrors they almost struggled to close and later putting the cabin lights on there was virtually nothing from the LED's.
I checked battery voltages, main one 12.4 and leisure about 9 with engine off and when running the main battery showed 14 but the LB still showed around 9. I removed the connections from the split charge relay and replaced the original fuses. Everything seemed to work fine. I am thinking that the LB has come to the end of its life, it wasn't an expensive one and if I remember was guaranteed for 3 years - so it hasn't done too bad.
So my question is until I can replace the LB should I disconnect from the split charge relay from the LB as I am not sure if it will be detrimental to the alternator trying to charge a duff battery?

[g8dhe]

Yes your likely to be "overcharging" the LB as it may be offering less resistance to charging, on the other-hand if its sulphated up then it will be a lack of charge! Whatever order a new one ASAP Tayna batteries do an excellent service, just measure the tray dimensions and height available and then identify a new LB that will fit with the correct terminal orientation which has the largest AmpHour capacity. https://www.tayna.co.uk/leisure-batteries/

[Eratosthenes]

Geoff,

Thank you for the reply and link to Tanya.
I will disconnect the LB and measure up the tray and order a replacement from Tanya.