Power problems, lots of questions.

[SaltyPipe]

On 02/01/2020 at 18:32, SaltyPipe said:

New engine battery at about 12.57 volts before starting (rested I assume)

@Tony Brooks Starter battery measuring 12.79 volts this morning

[Boater Sam]

Getting some amps then, good to see the OP now knows how to use a multimeter. He will find it a great help in the future.

[1st ade]

17 hours ago, Boater Sam said:

You are rare creature, we are lucky to have you around.

Seconded! - I hope someone as helpful as Tony is around if I'm ever in the claggy....

[Tony Brooks]

1 hour ago, SaltyPipe said:

@Tony Brooks Starter battery measuring 12.79 volts this morning

Good, near enough fully charged.

[Boater Sam]

23 minutes ago, 1st ade said:

Seconded! - I hope someone as helpful as Tony is around if I'm ever in the claggy....

We would be here for you!

(Unless its Winter then I'm 8000 miles away)

 

There are a few on here who would rally round and sort you out.

[SaltyPipe]

Hopefully this is a Split Charge Diode...

 

The very dirty red wire goes to the leisure bank (yay), the two brown wires go in the direction of the Alternator - not eyeballed directly but the alternator has a similar gauge/colour wire attached to it. Another similar wire goes up behind the main control board, hopefully to the regulator.

 

Anyway, does this look like a split charge diode? My googling shows me similar gadgets that claim to be!

 

Cheers,

 

SaltyPipe

 

 

[Detling]

Yes I used to have one but changed for a relay much better charging.

[Tony Brooks]

Well done. Yes, a passive split charge diode that probably drops up to 0.7 volt across it and thus badly compromises the charging unless you have a battery sensed alternator (you do not) or an alternator controller that converts the alternator to battery sensing (you do when its working).

 

 The cable on the middle terminal looks a bit thin to me and I suspect that is because your ammeter looks as if it is a "vehicle" type moving iron one and they tend to have been supplied with thinner than ideal cables. The problem with thin cables is you get even more voltdrop (loss of charging voltage).

 

I agree with Detling - if this were mine I would fit a decent VSR (voltage sensitive relay) but I would connect the alternator main output and any other charge sources to the domestic bank and then us the relay to connect the domestic bank to the engine battery when the system is taking charge from any source so both banks are charged. I would also fit a shunted ammeter shunt in the main negative on the domestic bank to monitor charging current and thus know when the bank is more of less fully charged.

 

[SaltyPipe]

9 minutes ago, Tony Brooks said:

if this were mine I would fit a decent VSR (voltage sensitive relay) but I would connect the alternator main output and any other charge sources to the domestic bank and then us the relay to connect the domestic bank to the engine battery when the system is taking charge from any source so both banks are charged. I would also fit a shunted ammeter shunt in the main negative on the domestic bank to monitor charging current and thus know when the bank is more of less fully charged.

Thanks again @Tony Brooks (and @detling), will definitely look at fitting the VSR and shunted ammeter.

 

SaltyPipe

 

[WotEver]

4 hours ago, Tony Brooks said:

The cable on the middle terminal looks a bit thin to me...

I was thinking that all 3 looked a bit thin. They certainly don’t appear to be 25mm