Hi all, my 70a split charge relay has packed up, this was already fitted into the van when i bought it 2nd hand years back from another windy, this used to read 14.4v on the controller when the van was running. Anyway i already have a controller that has got a charger inbuilt, and i could wire this up. BUT i was wondering if this will give me enough charge? OR if a split relay charger will be better in giving me a faster top up charge, because my round is tight with not to much driving. I use Yuasa EFB 100ah batts, 1 rotated daily, whilst the other batt is sitting ready on a mains charge at home using a 15ah victron energy charger. So the question is: What will give me a faster top up charge? Spilt Relay? OR would it be much difference than just using my (already have) easier controller option. Thanks m
Your Spring controller is also a split charge relay probably controlled with a voltage sensing circuit.
I have just looked at the fitting instructions of the Spring controller that has additional leisure battery charging and honestly, it won't do much as a leisure battery charger. My reasoning is that the protection fuse from the starter battery to the controller is 10 amp as is the protection fuse from the controller charge wire to the leisure battery.
So really you are replacing a 70 amp relay with a 10 amp relay. The saving grace would probably be the wire size restricting the 'flow' of current into the leisure battery. (Like trying to supply the needs of 4 households with water through a 1/2" hose pipe.)
A good split charge relay should be fitted with a minimum of 70 amp battery cable; 110amp would be better with a heavy duty Durite 140amp VSR (voltage sensing relay.)
However, as you don't do much mileage that relay isn't really going to do that much for you, even with extra heavy duty cabling.
A fellow window cleaner in the same village as us has a 2 man wfp system in his van but has no SCR. He swaps batteries as you do and has operated this way for some 14 or so years. His batteries are 85amph ones.
So really having a basic SCR or VSR isn't the best value for money investment as it has very little input back into the battery a day.
However, my first SCR paid for itself when we had a battery failure miles from base on a big clean. We were able to finish the clean with the engine running.
On the current van I decided to replace the VSR with a Sterling BB1260 battery 2 battery charger. (I didn't need to do this as my 62 plate van doesn't have a smart alternator or regenerative braking.) Once you start adding electronics into the charging process you will find that your leisure battery will get a better, quicker recharge. Alternators are truly terrible battery chargers.
I have always supplemented my VSR charge shortfall with a 'bench' charge every second night with the old van in summer and every night in winter. Doing the same mileage with the Sterling unit I have been able to run all week and end up with still a 98% fully charged battery. Driving to the bank on a Saturday morning of around 10 miles will top that up to 100%.
A standard relay (SCR or VSR) hasn't the electronics necessary to 'fool' the battery into accepting a faster recharge. But a Sterling unit with new HD charging cables and fuses does a really good job, but comes at a cost.
