Strange battery problems !!

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safariofhowth

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Having strange ( to Me ! ) problems with batteries

Have 1 x 96 Ah Starter Batt and 3 x 130 Ah Trojan Deep Cycle Batts, all 5 seasons old. Have solenoid that connects Serv Batts to Starter Batt for emergencies. Have 2 Alternators. Had 30 amp mains charger.

In Barcelona engine would not start even tho’ plugged into mains.
Started eventually having used solenoid to bring in Serv Batteries
Local expert checked everything and said all ok.

In Menorca after 5 days on anchor engine would not start – did eventually.
Went to Almerimar and had completely checked again. Told no probem – batteries ok. On recommendation had new 60 amp Battery Charger installed.

Motored tp Almeria. There bow thruster would not work and Cetrek autopilot gave low battery fault. ( both run from Serv Batts )
Back to Almerimar. All rechecked. Told to switch off fridge when using bowthruster. Batteries getting old !

In Lanzarotte engine would not start after 4 days on mains and new charger. Eventually started using solenoid / Srv Batteries

New charger gives 13.7 volts but Starter and Srv Batts show 12.7 v – how do I get 13.6 volts required by new SSB ??

Any thoughts ??
 
Usual questions - are you testing bat volts after allowing them to rest with no load? 12.7 sounds reasonable after charging, but does it hold its charge OK?

Have you checked the electrolyte if they are open lead-acid?

Do your alternators kick out the required volts? You should be able to get about 14.6V at the batts with a smart regulator.

What is the condition of your charging and starter cables and terminals? Poor contacts and cable voltage drop will make a big difference, especially with tired batts.

Sure that the SSB requires 13.7V from a 12V supply?

It does sound like the batts are on the way out though, and a good marine multi-step charger goes a long way to keeping good batts good for a long time.
 
sounds like bad batteries not holding the charge or a bad connection stopping the charge getting to the batteries. Try cleaning the battery connections and then measuring the voltage at each connection from the charger out to the battery terminal post. If it's 13.7 on the battery cable and 12.7 on the terminal post after a few hours charging, the battery has had it. It should get hot confirming its inability to hold a charge.

The SSB should operate down to 12V. Unless it is on low power setting it will draw enough amps to drop even a good battery down to 12 anyway. If you want 13.6 you will need to run the motor but on our boat that generated so much noise on receive that it was better to use the batteries.
 
as well as the usual suspects mentioned above and the low voltage does point more in that direction but one other thing that may be worth checking is your starter,had a similar problem with mine ,seemed like flat batteries coupled leisure up etc,it happened a few times,in the end took the starter apart,2 brushs worn and an accumulation of crud,cleaned it and replaced brushs all ok now.
are you charging the start battery directly from the charger or through a split charging diode as they wil give up to a 1v drop.
 
"Normal leisure will last a year for liveaboard "
there must be something wrong if you can only get 1 yr out of your battery mark dj, i expect at least 4-5 years with a standard 100 amp.battery proper maintanance charging is the key,do you think livaboards are made of money,
my last set lasted 6 -7 years and i only changed them as i was selling the boat,
my battery bank is 400amp service100 a start
 
The new battery charger is to big, your 30 amp was better, but to late to change.
Can you advise make and type of battery charger, how many outputs etc.
Put you voltmeter on the engine battery, and get someone to start the engine, check what voltages you see at battery terminals and make a note. Check engine charge volts, check both batteries.
Check the service battery volts, put some load on, say 20 plus amps, and watch the battery volts for say 30 / 60 minutes, make a note of the voltages say every 5 minutes.
Make a note of battery volts, and put the battery charger on, check volts at both battery bank terminals, and at battery charger ouitput. Make a note of volts say every 15 minutes for each bank, and amps if you can.
Come back with that gen, and an informed opinion can be reached, at the moment you are a bit short on detail.

Brian
 
Firstly, it sounds like you have had too many "experts" on board who don't know enough. "Turn off fridge when using bow thruster" - the advice should be turn off bow thruster when using fridge! The fridge draws about 6A, the bow thruster 100A+.
But I digress.
You say the engine wouldn't start. Does that mean it wouldn't crank? Or only lethargically? Under other circumstances did the engine need a lot of cranking?

You say you have motored for hours and used shore power charging for hours yet neither the starter battery nor the serv batts are properly charged or not holding their charge. The question to pose is whether this is both sets of batteries dying at the same time or is there a problem in the system which means the batteries are not really getting charge from both the alternators AND the shore charger. Hmm - need to know how they are wired up.

Let's separate the issues. Starter battery. You say you have 2 alternators. This normally means 1 for the starter battery and the other for the serv but it is not clear as to whether the shore charger has a second output which connecs to the starter battery, sometimes they are not because usually there is not a longterm draw on the starter battery and it is quickly recharged from the alternator. In any case if you have 12.7v at rest then you can assume the battery has taken about as much charge as it can.

As others have advised, 12.7v is fully charged and at rest with no charging device turned on. Make sure your emergency bridging switch is OFF. If you can measure 12.7v at the starter battery at rest, try measuring it when cranking the motor. It may drop to 12v or so but not much further if the battery is still good. If the voltage is still good across the battery terminals when cranking but the cranking is slow or weak, get the voltmeter right to the starter motor terminal and engine block to see what voltage is there. If it is lower, you have a cabling/connection resistance problem. Don't forget this could be in either the +ve or -ve side of the wiring and could be as simple as the connection of the -ve cable from the battery to the engine block. If it is still 12v then you most likely have a starter motor problem, either the internal solenoid/contactor or brushes or windings - a service/rebuild should fix it.

Service batteries. It is curious that they don't charge from either the alternator or the shore charger. It is possible that faultfinding the starter circuit you may find a wiring/connection problem which is common with the service batteries, such as a -ve return issue. That could also explain all charging is poor but failing that I think you have to reckon the batteries themselves are bad. You could try the same on-load test with a big load such as the bow thruster. Measure at the batteries at rest then when the bow thruster is on. It should tell the story quickly.

I had to replace my batteries, starter and 3x140Ah serv after 4 seasons of liveaboard use. They were only normal wet lead/acid but I think I caused them grief in the early days by using them too far down the discharge curve. If they have been discharged to below 12v (approx 50%) often then they will have a shorter life. As to why the starter battery died, I don't really know but it is common for car batteries to last only 3-5yrs these days so I take it as part of the game.

In short, I would sort out the starter battery first then move to the serv.
Ray
 
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