Leisure battery fast discharge

[MYndServe]

Hi everyone,

 

I have a 2003 Fiat Bessicarr E760 motorhome that I was stupid enough to purchase from a company called.....South Yorkshire motorhomes. .....It can with a (long) list of issues that I have had to repair myself. Anyway, a problem I have always had is the leisure batteries either not charging, or discharging within a couple of hours regardless of load. I have the following systems

 

x1 100w solar (with reg panel)

Sargent EC200 mains management.

X2 (now) leisure batteries. (daisy chained).

3000w inverter (now disconnected).

 

I do have a fair knowledge of mechanics (luckily) and electrical/electronics too. But even I am stumped.

 

The previous owner had xx leisure batteries attached. All were faulty so I replaced with x2 deep cycle ones. But I can drive for hours and when I pull up the batteries go from 12.2v to poor within a couple of hours. Even with nothing running. I disconnected the inverter and have even fitted an isolator between them So I can manually charge both, or just 1 at a time.

 

I can switch over to the engine battery via a panel. But this is not a great idea as we all know. There is a split charger next to the mains controller. And a black resin block under the bonnet with a led that is sometimes green, and other times red. God knows what it is though.

 

Finally, If I charge via the hookup the batteries will actually last 2 days, even with the over_sized inverter attached.

 

Please anyone......give me a new angle on this. I am planning to fit a 2nd solar panel. But seems little point at this stage.

[Tracker]

Welcome to the forum where everyone is an expert - except me!

 

You may have a split charge relay attached just under the edge of the bonnet close to the battery and it is very common for all the road muck and water to corrode the terminals and fuse holders which disrupts the current flow from alternator to leisure battery.

 

Not charging is one thing but early discharging is often quite another thing so you may well need to resolve two issues which always makes it more interesting.

 

Have you considered contacting the last owner via the V5 to ask about how it is wired up - assuming he did it and he knows?

 

Personally I prefer to wire two leisure batteries with the + & - input/output cables one to each rather than both to one. That way both batteries work equally rather than one as slave to the other. Might not make any difference but I think the batteries last longer that way - but I could be wrong!

 

Inverters take current all the time they are connected so always make sure it is left disconnected when not in use.

 

You sound as if you know your way around so are all the battery and fuse connections clean and tight?

 

Do you have a digital multimeter and know how to check voltages and low current discharge amps?

 

Dunno what the black resin box is - is it an alarm?

 

 

[Brambles]

Well the easy bit is you are not charging from the Alternator. Your batteries should, under charge, reach 14.2 or so volts and then when not being charged settle back to around 12.8 volts. (NOT 12.2)

 

So, you need to check out the split charge relay and circuits and its quite possible previous owner as mucked around with the system. I would start by checking out all the posible fuses ralated to alternator charging. There is probably a 40 Amp fuse near the batteries or near the engine battery. I am not familiar with the arrangement on your vehicle but would not be surpised to find some fuses and relays near the engine battery which are for split charging and the fridge to power up on 12 volts from the alternator. However the EC200 system may have them enclosed in a comtrol unit...I wil need to look it up. On the sargent website you can download wiring dagrams for many vehicles so I will see what I can find and post back...or someone else might 1st.

 

1st thing though, check your battery voltage is over 12.6 volts or they will be deteriorating through sulphation...get some charge into them by using your hook up lead.

 

 

[Robinhood]

..the split charge/fridge relay(s) and fuses are most likely on a bracket hidden under the black plastic (Fiat) shroud at the top rear of the engine compartment.

 

The most useful wiring diagram for your vehicle can be found here:

 

http://www.sargentltd.co.uk/Swift_Motorhome_schematics_2004.pdf

 

(I know it says 2004, but the 2003 motorhome link delivers caravan schematics - this 2004 version should be (virtually) the same as yours).

 

The black box is possibly a "battery master", as in this link here:

 

http://www.vanbitz.com/product/battery-master/

 

...where the function is described.

 

If there is a fundamental "on-road" charging problem, which leaves your vehicle battery low as well, the battery master (if it is such) will attempt to correct this by draining the leisure batteries, so, as John says, a check of the alternator charging circuits to both sets of batteries is probably the first point.

[Solomongrundy]

Do you have, or could you take, a picture of the resin block thingy?

 

I had what could be a similar device hidden away in the garage of a Knaus and I though it was some sort of live tracking device and because my batteries wouldn't keep their charge we got rid of it.

 

We never did sus out what it actually was or what it did but the battery performed better.

[Robinhood]

...the red/green led is what leads me to think it could be a battery master.

 

http://www.outdoorbits.com/Brochures/Battery_Master_Customer_instructions.pdf