[Anonymous]

Hope somebody can help.
I have a bav30 (2006) .The battery charger is conected to both the starter and service batteries. Both hold there charge.However the charger only charges the starter batt.To charge the sevice battery I have to run the engine.All the 12v sevices work. I have checked all leads and cables.Is there a fuse that may have blown?

[Anonymous]

Assuming the charger is correctly installed there should be a fuse on the positive feed from the charger to each of the batteries. So you will most probably have two fuses (or a block with two fuses on it) somewhere between the charger and the batteries. On my Bavaria 32 the charger is very close to the batteries so perhaps it is the same for you. The fuses should be easy to find.

It can only be:

1. blown fuse

2. loose connection at the charger or battery

3. internal fault in the charger causing the relevant output to fail. There is probably another output you could use for the service battery in that (very unlikely) situation.

Actually I had the opposite problem … my batteries were not charging properly when the engine was running. It took a very long time to stumble upon the problem … it was a loose connection at the split charging diode in the engine compartment. So now, each time I do any servicing, a tighten up the three nuts holding the thick cables onto the posts on the split charging diode.

[bobclements]

A bit of advice.  Ditch the splitter diode and replace it with a Sterling A to B charger.  You’ll get far better charging from the alternator.

[IanJCulley]

Bob

Can you explain in a bit more detail what the ‘A to B’ charger does.  Is it different to Sterling’s alternator regulator devices?

 

Ian Culley/ B32 ‘Another Fantasy’

[Anonymous]

Hi jonathan
First of all thank you. I will investigate all your points. The charger is next to the starter battery,the service battery is on the opposite side of the boat.I Cant recall seeing anything looking like a fuse but ill take another look. Thankyou again.
John

[bobclements]

Hi Ian

The diode splitter is basically a dumb device which splits the charge between the two battery banks.  One of the problems with them is that you suffer voltage loss through them of anywhere between 0.5 and 1.5 volts.  On my boat, I was only getting 12.9v out of the diode splitter, but the alternator was pushing out 13.6v.  As you can imagine, 12.9v is pretty rubbish.  If you have a modern alternator, you can just replace the diode splitter with a VSR, which basically does the same thing but without the voltage loss.

The Sterling A to B is an altogether different beast.  What it does is very clever.  It treats the battery banks completely separately. It charges the engine battery first, pretty much as you would get if the alternator was attached directly to it.  What it then does for the house bank is to drag the voltage at the alternator down so that the alternator produces maximum amps.  It them boosts the voltage back up.  The net result is that you get massively more charge going into your house batteries.  It also acts as a proper 4-stage charger, so will pause the fast charge every so often for a few minutes to let the batteries settle and cool, and once the batteries are fully charged it will put them onto a float charge.

It’s a really easy unit to install, as it just uses the same 3 connections as the diode splitter (so it’s a simple swap-out), and you just need to run a return cable to the battery negative system.

It does put a fair bit of load onto the alternator and can generate black dust off the belt, so you need to replace the belt every year or two, but it’s a complete game-changer when it comes to charging the house bank, especially if you have an older alternator like a 60a Valeo that was fitted by Volvo.

[IanJCulley]

Bob

Many thanks for the useful feedback.  Having just replaced the batteries on Another Fantasy (after some 10 years trouble free service – really!) I’d be a bit worried that if I fit one of these devices it will fry my shiny new Varta’s.  Should I worry??

 

Regards  Ian C

[bobclements]

Far from it.  It will look after your batteries far better because it carries-out proper intelligent charging, so there’s no chance of cooking them.

My current house batteries are 12 years old now and still going strong (but they are 6v Trojans).

Have a read – data sheet here

Instructions (talks about how it charges) here

• This reply was modified 4 years, 1 month ago by bobclements.

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