Battery Charging experts...help needed

[Mr Googler]

On my new to me boat I have a victron Blue charger with 3 outputs.

I have 3 battery banks...port/starboard/domestic (2 physical batts for domestic))

The charger outputs went to port batt and domestic and seemed to work fine going from absorption mode to float. The starboard batt however went flat so after a bit of digging, I found the 3rd charger output tucked into some trunking with the ring terminator missing. Duely reconnected that to the starboard batt and it merrily charged.

Great....however, the charge now stays in absorption mode at 14.4v.

Does the charger use negative to sense when a battery is full? What I don’t know is if all the negative terminals are joined on the batteries (and as they have been on all my other boats) Was going to test but my voltmeter batt went flat of course! Could be the starboard batt is not connected to the negative on the batt charger but would charge go into it if it wasn’t?

Any thoughts greatly appreciated. Batt charger is off at the moment.

 

[matthewriches]

I believe all the sensing is done via the positives, certainly the Centurer models are.

Is the stbd battery good? Apsorbtion should only last for so long depending on what value the charger is programmed in to be.

 

[Mr Googler]

Hi Matt

Can’t be sure the batt is good as the boat is new to me. Absorption should be 8 hours max from memory from the manual. Pretty sure it’s doing more than that. I’ll have to get or borrow one of those batt tester devices I think.

If the sensing is done by the positives, that’s one question down

 

[VicS]

On my new to me boat I have a victron Blue charger with 3 outputs.

I have 3 battery banks...port/starboard/domestic (2 physical batts for domestic))

The charger outputs went to port batt and domestic and seemed to work fine going from absorption mode to float. The starboard batt however went flat so after a bit of digging, I found the 3rd charger output tucked into some trunking with the ring terminator missing. Duely reconnected that to the starboard batt and it merrily charged.

Great....however, the charge now stays in absorption mode at 14.4v.

Does the charger use negative to sense when a battery is full? What I don’t know is if all the negative terminals are joined on the batteries (and as they have been on all my other boats) Was going to test but my voltmeter batt went flat of course! Could be the starboard batt is not connected to the negative on the batt charger but would charge go into it if it wasn’t?

Any thoughts greatly appreciated. Batt charger is off at the moment.

The battery would not charge if its negative was not connected

If this this battery has been allowed to go flat and left in a discharged state it may now be unserviceable. It may not be charging fully, which is why your charger is staying in absorption mode.

Disconnect the charging from it again and see if things return to normal.

If your charger has recondition mode try reconditioning this battery on its own

 

[Mr Googler]

Thanks Vic

Glad you responded. I will do that and yes it does have a recon mode.

My charger is a victron blue power ip22

https://www.victronenergy.com/uploa...ry-Charger-(1)-(3)-IP22-EN-NL-FR-DE-ES-SE.pdf

The starboard battery wasn’t dead but not enough to start the engine easily.

All batts are wired to negative but not sure if all the negs are together and therefore whether all batts are wired to the charger negative. Just to confirm, if one batt wasn’t wired to the charger negative.....it wouldn’t charge?

Will get going with the volt meter tomorrow having bought a new battery for it today!

 

[VicS]

Thanks Vic

Glad you responded. I will do that and yes it does have a recon mode.

My charger is a victron blue power ip22

https://www.victronenergy.com/uploa...ry-Charger-(1)-(3)-IP22-EN-NL-FR-DE-ES-SE.pdf

The starboard battery wasn’t dead but not enough to start the engine easily.

All batts are wired to negative but not sure if all the negs are together and therefore whether all batts are wired to the charger negative. Just to confirm, if one batt wasn’t wired to the charger negative.....it wouldn’t charge?

Will get going with the volt meter tomorrow having bought a new battery for it today!

Thanks for the link to the manual. I find it helps to know exactly what equipment is involved. Minimal installation/ connection instructions though.

I would expect all battery negatives ( except when a battery monitor is installed) and all battery charging negatives to go to a common point / negative busbar.
(It's not clear from the Victron manual if it has three separate negative outputs)

 

[Mr Googler]

Hi Vic

The plot thickens!

All batts after 3 days standing read 12.86 ish across the terminals.

This following was all with isolators off.

All negatives have continuity so that’s good.

Strangely, the starboard positive has continuity with the domestic positives even with isolators off. The victron outputs go to the isolators. I disconnected the victron output previously reconnected to the starboard batt thinking if I have continuity between starboard and domestic....it will charge surely.......err no!

There’s a new split charging diode for starboard / domestic charging from the engine so I’m now thinking the previous engineer that fitted it has got something wrong. It was only replacing one that was already there.

I think the best thing is to trace the victron outputs and put them directly to the batts (do you agree?) I need to check all the isolators are actually functioning then check the wiring to the split charger diode is correct.

It was blowing 50 knots whilst doing this so gave up after 40 mins to tighten lines and save a friends yacht which was popping fenders for fun!