Leisure Battery Not Recharging

[HazMeleri]

Help!
We had a faulty ( four cells dead) leisure battery that eventually gave up the ghost.
I replaced the leisure battery with brand new one, reconnected it up and power is working in the habitation unit.
However, there is no charge being sent to the leisure battery when the engine is running, and the Sargent control unit is showing 0.0v for the vehicle battery.
Can anyone point me in the right direction? It's an Autotrail Apache (2008) with a Sargent EC328PSU and a solar panel.

Also, we are traveling to north Wales from Cardiff on the weekend, is there a anywhere along mid Wales or along the borders with Wales where we can get someone to look at it. I'm assuming we'd need an auto electrician with experience with Motorhomes. Would a marine electrician be of any use?
Thanks

 

[grasscutter]

There should be a large 50amp fuse next to the vehicle battery assuming it’s the standard alternator charging.

 

[RogerIvy]

As Grasscutter said, probably a fuse. You may need to search in strange places, sometimes that fuse is places difficult to access (like “under” the EBL)

 

[GeoffnDee]

There should be an interface unit , either an EM40 or EM50 , behind the drivers seat and it could be a faulty fuse within it causing this problem..

 

[autorouter]

However, there is no charge being sent to the leisure battery when the engine is running, and the Sargent control unit is showing 0.0v for the vehicle battery.

Just so you know what is going on, the power to charge the leisure battery comes from the alternator/vehicle battery to the Sargent fusebox, to a relay inside the fusebox. There will be a big fuse on that wire somwhere, either next to the vehicle battery or in the EM40/50 box as GeoffnDee says.

The relay in the Sargent unit connects the leisure battery to the alternator/vehicle battery when the engine is running. Also that wire to the vehicle battery is the method used by the Sargent unit to measure the vehicle battery voltage, so if the fuse has blown that's why it's reading zero volts.

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[HazMeleri]

Thank you all for your help. The replies pointed my husband in the right direction and he found a blown fuse in the EM50 box for the vehicle battery.
Swapping this out fixed the 0.0v on the display and probably the split charging too.
As always he's gone a bit OTT on Amazon and got himself a voltmeter and a 250 piece box of replacement fuses

 

[autorouter]

Swapping this out fixed the 0.0v on the display and probably the split charging too.
As always he's gone a bit OTT on Amazon and got himself a voltmeter and a 250 piece box of replacement fuses

It's the start of a slippery slope, I'm afraid.

However it's a very useful diagnostic tool. A battery not being charged and not under load will have a voltage of about 12.0V (fairly flat) to 12.7V (full) depending on the exact type. If the voltage is 13.0V or more, then something is charging it. You can use that fact to find out if the split charging is working when the engine is running. About 14.0 to 14.5V is typical. It shouldn't be over 15V.

 

[Beryl]

Just as a precaution, it might be worth reading through this thread from Grommet regarding cheap bulk-buy fuses (clearly I don't know which ones you actually bought - they may well be fine!)

Broken Link Removed

 

[Tombola]

got himself a voltmeter and a 250 piece box of replacement fuses

thats a good idea, a voltmeter can get you all sorts of answers easily.

Amazon product ASIN B07TKXT1V6these are good too...(there are cheaper) whens his birthday

 

[Lenny HB]

voltmeter and a 250 piece box of replacement fuses

I hope he bought branded fuses and not cheap Chinese junk as they can be a liability & fire risk.

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