Bongo Fury

Just after some info about the Willinton kit operation, my Bongo came with this kit already fitted, very poorly might I add, whoever fitted it left the original fuses in as well as the wiring to re route the interior electrics meaning the starter battery & leisure battery were always connected together in parallel, once I rectified this I found the relay was not clicking it to charge the leisure battery when the engine was running, this turned out to be a poor earth connection at the relay as it was bolted to the coated metal bracket, a new earth connection & it sprung back into life & is charging the leisure battery when the engine is running.
However I decided the other day to stick volt meters on both batteries to check it was working ok (don't really trust these voltage sensing relays for split charging) & found the leisure battery is not being charged all the time when the engine is running, the relay seems to be regularly cutting off for a few minutes at a time, revving the engine or turning on or off electrical loads makes no difference, it can do it when idling at lights or going along doing 60mph. The charge rate on the main battery never drops below 13.8 volts minimum but normally over 14 v so the alternator is not the problem. I managed to get a look at the relay when it wasn't charging the LB when I was stationary & the little green LED on the top of the relay was not on.
So my main question is, Is this normal operation of these voltage sensing relays ? do they monitor the voltage in the leisure battery & switch the power on & off as necessary ? I assumed it should stay switched on as long as the input voltage is over the set amount regardless of the LB voltage ?
Does anyone know where I can get a replacement relay without buying a full new kit ?

Not sure of the exact relay you have but generally they work by sensing the alternator voltage and when it reaches a set level the relay turns on. When the alternator voltage drops it will turn off, possibly after a short (up to 10 seconds) delay. To test it, I would disconnect the output side (the wire which links from the relay to the leisure battery) then connect a voltmeter to this terminal and ground. With the engine off this should show no voltage. Then turn on the engine and (possibly after a couple of seconds) you should see the alternator voltage on the output of the relay. If no output try revving the engine up a bit to get the alternator up to voltage.

The relay should not drop out while the engine is running at decent revs (say 1500-2000), it just depends on the input voltage. If you see it turning on and off then recheck all the connections and earths as it sounds like it was not fitted very well originally.

I used one of these and it works fine -
http://www.ebay.co.uk/itm/181160779910

wire a multi meter into the alternator supply so you can read it while your travelling, or to the starter battery lead. just to make sure its not an intermittent alternator fault, if output drops the relay could be sensing this and dropping out, then as it rises again comes back in.

ive known a few of those go faulty, so i use these myself.

http://www.ebay.co.uk/itm/SPLIT-CHARGE- ... 4d160c8ed0

Other things to check would be the fuses - there will be a wire from the starter battery through a fuse to the input side of the relay (if not you should add on as soon as possible, I would recommend you do not use the vehicle without!) - sometimes people use the cheap clip-on fuse holders and the wires in this may be loose. That would give you a flaky feed into the relay and could explain why it's intermittently dropping out.

Just take care when disconnecting/reconnecting on the output side as the relay may stay on for several seconds after the engine stops so the output side may still be live.

The other thing to do is email the maker - Martin Bird - and ask. He's extremely helpful, and I'm sure that he can advise the best solution.

PM me for his email address.

He is no longer making these kits but you could contact for help.

Martin Bird
125 Willinton Road
Knowle
Bristol
Avon
BS4 1HY
United Kingdom

Phone: 01179|535985
Email: [email protected]

I'm 100% confident the alternator is working properly, like I said I've had voltmeters on both batteries at the same time & the charge rate at the starter battery never drops below 13.8v minimum at any time with the engine running. After seeing how badly it had been fitted I went over every single connection myself, the positive cables from the relay gong to both batteries have been fused at the battery's with decent strip fuses with bolted connections. I have even volt drop checked the cables under load & the are fine. When the LB stops getting charge to it the little LED on the relay goes out aswell.
I would say it looks like a faulty relay but was just looking for confirmation that its not supposed to cycle on & off like the way it does. I'm going to fit an isolator switch between the two positives as a backup in case the relay fails completely.

Before you replace the relay you could see if it has an adjustment - mine does - which will change the voltage at which it cuts in and out. You could try lowering the voltage just a little to see if that helps (although not sure how you can tell which way is which on the adjuster, may have to be trial and error).

I seem to recall several people had that sort of problem and it appeared that he had a bad batch of relays, he replaced them as far as I am aware so might be worth a call to see what he says.

I wonder why he stopped making them?

Having made and sold kits myself, you simply get worn out! It gets very tedious putting together the same item after several years

He still does other stuff - e.g. battery cables, fuses etc

I got some bits from him recently, excellent accurate and fast service....

Just to update a bit.
I'm looking for a replacement relay for my willinton kit, it would appear the relays are modified to make them voltage sensing so googling the part numbers just brings up a standard heavy duty 100amp relay. I'm aware the maker doesn't manufacture the kits anymore but have tried contacting him via email and his eBay account to see if he can just supply a replacement voltage sensing relay but have not had a reply from either email or eBay.
Can anyone else on here manufacture the 100amp voltage sensing relays ?

Martin MAY be producing a new relay I recently (and stupidly) screwed mine up and Martin sold me a new one he "had been working on" .

He was certainly very prompt in replying to my enquiry, as he always has been.

Is this any good...


http://www.ebay.co.uk/itm/221175131555? ... 1423.l2649

You could always go down the Piggyback route, IE 30amp VSR £10.00 and 100 amp relay £12.00.=£22.00