Hi, I know there's been a few threads regarding split charging leisure batteries and was wondering..... I have a 110amp leisure battery and I've been looking on flea bay for a relay. A lot of the cheaper ones are 30amp, can I use one of these or do I need to get a bigger one say a 140amp relay which are obliviously bigger bucks. Ta in advance
there was an excellent article on the type2.com site about split charging and cable size...it's tempting to use larger cable, thinking that it will charge more effectively...it won't. I'll try to dig out the thread and post it here...
You could go for R20B from here http://www.vehicle-wiring-products.eu/VWP-onlinestore/relays/relays.php £1.87. Though I always like to over spec things so you could get R40B or R30AF with a built in fuse.
I was thinking 30amp, but the reason I asked is because a seller on flea bay stated in his blurb, you would need a bigger amp relay for our kind of vehicles and batteries, because a 30amp would overheat.
For some reason I always had problems with the standard relays, my batteries would go flat after about a week and my leisure battery would'nt charge so I got one of these and its been fine ever since works a treat http://www.ebay.co.uk/itm/SPLIT-CHARGE-RELAY-12V-30AMP-INTELLIGENT-SELF-SWITCHING-/200713031524?pt=UK_Campervan_Caravan_Accessories&hash=item2ebb6dcf64
A good 30amp relay not a £3 one will be plenty big enough I use the one shown in the kit shown in the how too i get it from VWP and it comes with a built in 30amp fuse and costs around £9 i have fitted loads of these and never had a problem. My current van has a 110amp/hr battery and has been running for 2 years with one. Some people have had problems with smaller relays braking or fuses going but when you look into it they have taken the feed from the coil so draw megger amps when they start up.
It is pretty simple earth the leisure battery. Take a feed from positive to a fuse box (fused at battery end) Then you can connect anything you like to the fuse box. I put mine under the rock and roll but some prefer it up front.
I dont have one of the intellectual relays but believe they are good and get over any mis-connection issues or the relay being energised on startup potentially causing an overload accross the relay blowing the fuse if there is one or frying the contacts. Sometimes they get welded shut and the batteries are permananetly connected together pos to pos. Not the best idea. If you are fitting a standard accessory relay it needs to pick the coil feed up from something that is live when the engine is running rather than on start up (as it would be when fed from the coil) on a type 4 that is easy as (from memory) you tap into the blue wire from the alternator to the contol unit on the lhs of the engine bay. I dont know about 1600s but they must have an equivalent. Dynamos then no idea! So in effect a standard relay connects the positive terminals of both batteries together when the engine is running and they share the charging output from the alternator. When the engine is off the relay drops out disconnecting the batteries from each other to prevent load sharing and draining your main battery. A feed from the live terminal of the leisure battery goes to a fuse-box which feeds your camping accessories. Simples
The issue with the automatic ones is the cut in and cut out voltage is quite high around 13.5 v The regulators on our van cut in at around 12.2 volts so you may not be charging on tick-over or just above or if your battery is suspect.
I got this one: http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=130443910121&ssPageName=ADME:L:OU:GB:1123#ht_1561wt_905 cut in 13.5v cut out 12.5v seems to work fine with my alternator, puts out more than 13.5v at idle under normal circumstances The way I understand it is that if the voltage is being pulled down too low for the relay to cut in due to engine idling and a very low main battery, that the LB wont be charging, probably a good thing in my view? I'd want all the charge going to my main battery in that instance and the LB can wait until I get rolling.
Was someone on here selling some sort of kit for the split charge fuse box the lot ? Had a quick look but can't find it now
