flat leisure battery,main battery weak.any suggestions?

[hogggman]

hi,
just been out to the bongo and found the main battery very low,struggled to start the engine,and the leisure battery was flat.all fuses ok,possibly a poor connection somewhere.only a week since i got the split charging circuit working,so may be a teething problem from that.
any ideas anyone?
thanks
jamie

[Aethelric]

hi,
just been out to the bongo and found the main battery very low,struggled to start the engine,and the leisure battery was flat.all fuses ok,possibly a poor connection somewhere.only a week since i got the split charging circuit working,so may be a teething problem from that.
any ideas anyone?
thanks
jamie

Could be the radio. There is a wire which normally goes to the ignition, so it gets powered down when you switch the radio off. If that is reconnected to the leisure battery it draws current even when the radio is switched off. Mine was taking 0.4Amps. Thats around 10ampere hours a day and would make the leisure battery over discharged within a few days. I put an extra switch in this line and it works fine now.
If the split charge circuit is connecting the batteries together too soon, then the leisure battery will be sucking a huge current from the main battery as the main battery is trying to start the engine. It would struggle.

Dave

[moonshine]

Could be the radio. There is a wire which normally goes to the ignition, so it gets powered down when you switch the radio off. If that is reconnected to the leisure battery it draws current even when the radio is switched off. Mine was taking 0.4Amps. Thats around 10ampere hours a day and would make the leisure battery over discharged within a few days. I put an extra switch in this line and it works fine now.
If the split charge circuit is connecting the batteries together too soon, then the leisure battery will be sucking a huge current from the main battery as the main battery is trying to start the engine. It would struggle.

Dave

That seems a lot for a radio to drain, Dave. Surely the permanent live feed to the radio is just for the memory which keeps the pre-set channels active. I have no leisure battery in my Bongo, as it is mainly used as an MPV, but I do have a very old radio with pre-set channels. The Bongo is often not used all week while I am working, but I don't have any problem starting it when I need it.

Regarding the split charging, I have this on my boat and it is the simplest of systems. The split-charge relay is energised when I turn on the ignition and I have never had any problems with that either.

I would suggest that Jamie has a short circuit somewhere which is bypassing the split-charge relay, or he has battery problems.

Colin

[Aethelric]

Could be the radio. There is a wire which normally goes to the ignition, so it gets powered down when you switch the radio off. If that is reconnected to the leisure battery it draws current even when the radio is switched off. Mine was taking 0.4Amps. Thats around 10ampere hours a day and would make the leisure battery over discharged within a few days. I put an extra switch in this line and it works fine now.
If the split charge circuit is connecting the batteries together too soon, then the leisure battery will be sucking a huge current from the main battery as the main battery is trying to start the engine. It would struggle.

Dave

That seems a lot for a radio to drain, Dave. Surely the permanent live feed to the radio is just for the memory which keeps the pre-set channels active. I have no leisure battery in my Bongo, as it is mainly used as an MPV, but I do have a very old radio with pre-set channels. The Bongo is often not used all week while I am working, but I don't have any problem starting it when I need it.

Regarding the split charging, I have this on my boat and it is the simplest of systems. The split-charge relay is energised when I turn on the ignition and I have never had any problems with that either.

I would suggest that Jamie has a short circuit somewhere which is bypassing the split-charge relay, or he has battery problems.

Colin

It is a lot Colin, but thats what I measured. I was very surprised. Its a new radio which I put in to replace the bongo one. There are two power wires, one which goes directly to the battery (for the preset channels, and one through the ignition. The radio switches off if this one is disconnected. But when its connected, it draws 0.4A even when the radio is switched off.
Have you ever had to start your boat with a flat leisure battery Colin?

Dave

[dandywarhol]

My Sony 6 disc changer/radio draws 0.5 amp when left on standby

I need to remember to fully switch it off these days

[moonshine]

It is a lot Colin, but thats what I measured. I was very surprised. Its a new radio which I put in to replace the bongo one. There are two power wires, one which goes directly to the battery (for the preset channels, and one through the ignition. The radio switches off if this one is disconnected. But when its connected, it draws 0.4A even when the radio is switched off.
Have you ever had to start your boat with a flat leisure battery Colin?

Dave

Seems I misunderstood you, Dave. The radio draws 0.4A from the ignition-controlled supply even when it is switched off?? I thought you meant from the permanent live. What on earth is drawing power? Sounds to me like you may have a faulty radio, as I would have thought that it would draw no power at all when switched off, except the memory circuit drawing a few milli-amps from the permanent live.

Regarding starting my boat with a flat leisure battery, I have never had to start it with the leisure battery completely flat, as I have 220ah leisure battery capacity, but even when very low I have no problems starting at all. However, if I did, I could always turn off the main isolator on the leisure battery to stop the starting battery draining into it when I switch on the ignition. Usually though, the batteries are only connected together through the split-charge relay for less than half a second before I turn to the start position, so it is immaterial. Once started, both batteries charge up normally, and everything is ok. On a car, the relay feed could be connected to the accessory terminal on the ignition switch, rather than the ignition feed as on my boat. (It has no accessory terminal). The accessory terminal goes dead on most vehicles when the key is turned to the start position, so the relay would drop out until the engine fired and the key was released.

Colin