Battery Issue

[Ratty & Moley]

Hi Folks,

 

We had a flat battery over the weekend after mooring up in the middle of nowhere. So I disconnected the starter battery and connected the leads to the leisure battery and we managed to get under way. Can anyone recommend something that doubles up as a jump starter as well as a charger so I don't have to go through this again - well not soon anyway. I need to get the leisure battery charged - it's a dual purpose multicell, whatever that means. There seems to be different types of chargers for different batteries and I'm getting confused with all the technical jargon, so any help would be greatly appreciated. thanks

[grahame r]

I don't quite understand, did your domestic battery/ies go flat or your starter battery? If it was your starter battery then either you have a charging/alternator problem or your battery needs replacing. If it was your domestic then you really need to look at how much power you intend to use and what size battery bank would be suitable and then how to charge it. I don't think a portble jump starter type device is a practical long term solution.

[Paul C]

A simple pair of jump leads, in fact if your negative connections are good then you'd only need the one, would allow you to temporarily bridge between the leisure bank and the starter battery. If the starter battery is really knackered then it may pull down a part-depleted leisure bank and not provide enough voltage for starting though.

 

The simplest thing is to replace the starter battery as soon as it starts flaking out.

[Ratty & Moley]

Hi Grahame

 

I'm not really sure to be honest. I think that they batteries may have been the wrong way round as the one that is flat and was originally connected as the starter battery that is the dual purpose multicell SFL 110ah leisure battery ( thats what the sticker on the battery states) then the other battery which is now connected as the starter one, is a smaller battery, not sure exactly as its on the boat and I'm at home now. What is the difference between a starter battery and a leisure one and how do I know which is which - what size should they both be ?? we have a little 30ft springer, no inverter, and no major need for massive amounts of leisure use other than the lights in the evening as and when we are out ??

[bottle]

Hi Grahame

 

I'm not really sure to be honest. I think that they batteries may have been the wrong way round as the one that is flat and was originally connected as the starter battery that is the dual purpose multicell SFL 110ah leisure battery ( thats what the sticker on the battery states) then the other battery which is now connected as the starter one, is a smaller battery, not sure exactly as its on the boat and I'm at home now. What is the difference between a starter battery and a leisure one and how do I know which is which - what size should they both be ?? we have a little 30ft springer, no inverter, and no major need for massive amounts of leisure use other than the lights in the evening as and when we are out ??

 

That may be the biggest, little question that anyone can ask.

 

Some would say that there is no difference between the two, other than the label and the price.

 

Your start battery needs to similar to a start battery in a car and of suitable size for your engine.

 

Your 'leisure' battery(s) needs to of suitable size to cope with your usage. Remember that it/they should never be discharged to lower than 50% SOC (State of Charge)

 

If your start battery went 'flat' then either it is 'dead' and needs replacing or the alternator is not charging it and needs looking at.

 

or

 

I suspect you have only one alternator and a split charge system (diode or relay) and that the alternator charges both batteries (Start and Leisure).

 

If the split charge system has failed and depending on how it is wired that could also be a reason one of the batteries (start??) is flat.

[grahame r]

Hi Grahame

 

I'm not really sure to be honest. I think that they batteries may have been the wrong way round as the one that is flat and was originally connected as the starter battery that is the dual purpose multicell SFL 110ah leisure battery ( thats what the sticker on the battery states) then the other battery which is now connected as the starter one, is a smaller battery, not sure exactly as its on the boat and I'm at home now. What is the difference between a starter battery and a leisure one and how do I know which is which - what size should they both be ?? we have a little 30ft springer, no inverter, and no major need for massive amounts of leisure use other than the lights in the evening as and when we are out ??

Did the engine not turn over or did the lights go dim?

[Ratty & Moley]

The engine turned but not enough to turn over completly. And we do have a split relay to the alternator which as you suggest may not be working properly. I think I'll check the connection as may have loosened. What do most folk carry on board to help them out of this kind of a situation ?? a charger and if so which one ?

thanks

[Arthur Brown]

A typical "jump start" battery may not cope with a diesel as found on most boats, Something from http://www.machinemart.co.uk/shop/search/filter/clarke-jump-starts/type/any/module/shopcategory/page/1 may be better but will be more expensive.

A jumpstart battery will need regular charging to be ready for use.

 

My first suggestion would be to check the charging circuit throughout. The Start battery should never get below 95% SOC and should last for years.

 

This time of year a solar panel will provide lots of free electricity. A DC clamp meter will tell you where the current is going and not! I'd guess that something in the starter battery circuit has a failed (dirty) connection or something similar.

 

In simple theory a single jump lead from House +ve to Starter +ve should be enough to let the system charge both batteries.

[Chris Pink]

Hi Folks,

 

We had a flat battery over the weekend after mooring up in the middle of nowhere. So I disconnected the starter battery and connected the leads to the leisure battery and we managed to get under way. Can anyone recommend something that doubles up as a jump starter as well as a charger so I don't have to go through this again - well not soon anyway. I need to get the leisure battery charged - it's a dual purpose multicell, whatever that means. There seems to be different types of chargers for different batteries and I'm getting confused with all the technical jargon, so any help would be greatly appreciated. thanks

 

You would be better off buying a new battery rather than a 'jump start' battery.

 

If it's too flat to start the engine a day after a cruise and you are reasonably confident your charging is working then it's knackered.

 

Do you know whether your charging is working (voltmeter?)

Edited June 5, 2013 by Chris Pink

[Arthur Brown]

If you are still in the middle of nowhere then it's up to you to determine whether the start battery was flat from it's own demise or from a death in the charging circuit. The start battery is one of the most critical parts of a boat so the charge circuit needs to be right and working. As a reasonable start in warm weather should only use one or two% of battery capacity you could have 50 starts in a full battery so any fault could have happened a while ago.

[grahame r]

Chris Pink is probably right about your battery, if you've just bought the boat then the old owner is unlikely to have renewed it recently. There are numerous threads on here about battery charging and battery capacity calculations. If you have halogen or other high energy lighting then changing them for LEDS should be high on your priority list.

[smileypete]

The engine turned but not enough to turn over completly. And we do have a split relay to the alternator which as you suggest may not be working properly. I think I'll check the connection as may have loosened. What do most folk carry on board to help them out of this kind of a situation ?? a charger and if so which one ?

thanks

For diagnosing any problems like this it's good to have a half decent multimeter as a bare minimum.

 

The problem itself could be one or more of: failing batt(s), defective alternator, failing starter, bad batt isolator, defective or undersized split charge relay, corroded or loose batt terminals, poorly made or corroded crimp terminals, broken alt or split relay connections, undersized wiring so on....

 

Trying to diagnose the problem via a forum without any voltage or current readings whatsoever is really not the best way to go.

 

In the longer term it'd be good to fit a half decent panel voltmeter, and at least get some idea of what readings to expect when things are working normally.

 

cheers, Pete.

~smpt~

[Ratty & Moley]

Thanks Pete..... Purchased the voltmeter today

[smileypete]

OK sounds good, was it a multimeter or a panel meter?

 

When the engine is running you should see up to 14.2V - 14.4V at the batts, if they need a good charge it could take while to get there. If the voltage doesn't ever get to this level or it takes aaaages there could be an alternator/isolator/split relay/wiring problem. Once the batts have been charged at 14.4V for a good long time then the start batt should start the engine next time with no problems.

 

When the batts are being used, if the voltage at the batts settles to 12.2V with no loads on then they're at about 50% and it's time to recharge. If they're being well used each day it's good to ensure they get a good long 6-8hr charge about once a week if poss, continual daily shortish charges may cause some capacity loss due to 'sulphation'.

 

When charging from 50%, if the voltage at the batts jumps up to 14.4V right away, it could be the batts aren't taking a charge very well due to the dreaded sulphation, or maybe they're just on the way out. A series of good long charges may help things, or some 'equalisation' charging which could be a topic for another day.

 

When working around the batts, be sure to follow the safety recommendations in The Battery FAQ at http://www.batteryfaq.org. The Battery FAQ is also a good definitive source of info, but also well worth a look is Tony Brooks course notes at http://www.tb-training.co.uk and the course itself. Don't forget to check/top up the unsealed batts.

 

Hope this all makes sense OK

 

cheers, Pete.

~smpt~

Edited June 7, 2013 by smileypete

[Ratty & Moley]

Hi Pete, thanks for all the info ... I certainly have something to refer to now the volt meter is a digital multimeter.... Took us a while to figure out which setting to put the dial on but hey ho - I also bought a battery charger and popped the the battery on charge overnight - it's taken about 22 hours to get to 14v now so hoping all will be ok. I'll check the other batt once I'm back on the boat- thank you so much for all your help - much appreciated :)

[Nightwatch]

What has happened to us (caught us out)has been the electric isolater thingymajob.we have the heavy duty one, not the little red key type.

 

If it doesn't make good connecton it gives all the symtems of a flat battery(s) I took it apart and cleaned all the bits and bobs and hey presto it worked. It wasn't the batteries at all.

 

Just a thought.

 

Martyn.

[Ratty & Moley]

Thanks Martyn .... That's handy to know for future ref. in this case it was the battery. I now have to start the process of elimination as to why ...... Could take us a while

[Nightwatch]

One thing on a boat I just can't get myself to understand is electrics. All this talk of gadgets and multimeters and diagnosis just throw confusion into the ring.

 

I'm the bloke who just takes things apart and hopes for the best.

 

Hope you find the problem sooner rather than later.

 

Martyn

[Arthur Brown]

battery on charge overnight - it's taken about 22 hours to get to 14v now so hoping all will be ok.

 

That's a good sign - the battery progressively accepted charge so it was flat rather than dead.

 

IMO there is an issue with the charging system and may have been for a while. Something is stopping the battery charging. a full battery will start the engine several times but get flatter each time til you are stuck again.

[Ratty & Moley]

Ok folks so it would seem the alternator is not charging the batteries. A friend checked the current supply over the w/e and all connections etc are receiving what they should from the batt. Roughly how much does a new alternator cost and where should I buy it from ??

[Chris Pink]

it doesn't sound like you've eliminated the alternator yet. The keys to diagnosis are 1. does the red light stay on or go out (and does it light before you start the engine) 2. what voltage at the batteries when the engine is running and 3. what voltage at the alternator main terminal (big one) when the engine is running.

 

If you post those results we can tell you whether your alternator has had it.

 

If you need to replace it, first take it to an alternator repair specialists. Or get one of eBay, considering at the same time whether it is worth getting a more powerful one (there's not much difference in price)

 

But, as I say, you haven't given enough information to write off your existing one yet.

[Ratty & Moley]

Hi Chris

 

The red light does come on as soon as I turn the key and no the light doesn't go off at all even after a couple of hours of cruising.

Not sure what the voltage the batts are when the engine is running but will check next time we are out there.

 

Regards

A

[Chris Pink]

If the light doesn't go off then you're probably right about the alternator broken.

 

Sometimes you have to rev really hard to get it to go out, time is irrelevant, if it doesn't go out immediately then it won't later.

 

As I say, your cheapest option is to get it repaired, whereabouts are you?

[Ratty & Moley]

Hi Chris

 

Wer'e on the tow path opposite Gayton Marina.....

[Chris Pink]

So forum members in the area, reputable vehicle electrical specialist in the vicinity of Northampton?

 

 

Google produces two (random);

 

www.jsb-autoelectrical.co.uk/‎

 

www.northantsautoparts.co.uk/‎

 

I know neither, not my area, but worth a ring.

You have tried revving hard to make the light go out?