Battery Charge issues

[Ianburtoncamera]

Hi

I've an issue with my battery and or charge system on my 2001 B40 and would appreciate some advice.

They are, I presume the original batteries and charger from new. I had a marine electrician come on to test the batteries a few weeks ago as they were not holding a charge as long as they did in the spring just after we bought the boat in february, we found that lights were dimming or nav equipment was failing after a few days in Portpatrick with no shore power, we put it down to either the batteries needing changing, or to us putting more demand on the system and taking what worked well on a long cruise in April for granted and just piling on the power.

The electrician said that all three batteries (2 domestic, 1 engine) were fine although they were a little low in capacity, but he said this shouldnt affect us too much.

Last weekend I found that the lights were dimming whilst on a buoy, the next morning I put the hook down and found that even with the engine running the windlass just slowly and uselessly spluttered into nothing, not enough power to even lift the anchor off the seabed, as I say even with the engine running.

Can someone suggest how I test the system myself please? I have a volt meter and can test it, I just don't know exactly how to test it to find the problem...could it be the charge system, the batteries?

It's not the windlass I don't think as it's worked without a problem even without the engine a month ago.

for more info, we have the fridge running off the batteries when we are out, the lights on inside (obvs when it got dark), nav equipt, radio etc. It is on shore power 4 days a week when we are their. to me either the charge system from the engine is faulty or something similar, but i'm not an electronics fan so i'm out!

Cheers

Ian

[tiger79]

After 15 years, it's more than likely that the batteries need replacing.  I'd do that first then see whether you still have problems.

[Ianburtoncamera]

Thanks Tiger79. That's disappointing after spending a lot asking an electrician and him saying they were good.

Another question, Ive heard a lot about leisure batteries for boats, the theory seems to be that the term marine batteries actualy doesn't mean anything, and they are the same as normal leisure batteries for vans etc that cost a lot less.

Is this true?

Cheers

I

[tiger79]

There's a huge range of different batteries available, and to some extent you get what you pay for.  Cheap "leisure" batteries from a caravan shop will work fine, but perhaps not for as long as better batteries.  For the domestic batteries, I favour maintenance-free "deep cycle" batteries, as they are clean and spill-proof.  For the start battery, any ordinary car starter battery will do, but again a spill-proof maintenance-free design will be better.  AGM batteries cost more, but will accept charge more quickly so can be advantageous for the domestic bank - new Bavarias are fitted with AGM batteries as standard.

[MarkTheBike]

Hi Ian
Although not quite the same as you, we bought our B34/2001 a couple of years ago and her domestic batteries were completely shot. They were the originals but the previous owners hadn't used the boat for a while and just left her in the marina, plugged in to the shore supply with the charger always on. I understand that keeping them constantly charging is a recipe for 'cooking' older batteries if they are not able to discharge from time to time. Could this be the cause of the apparent sudden collapse in battery health?
Cheers

[sy_Anniina]

Hi Ian,

I'm pretty much in similar boat as you, this spring bought 2001 B40 and just recently found out house batteries are out. The only difference is that my house batteries were already at least once changed / upgraded to 3 x 180Ah. Based on age alone, I would assume your batteries are out as well.

Being a physicist and having worked with electrical systems for quite some time - my quick troubleshooting flowchart

• get a multi-meter capable of measuring either voltage or current, get familiar on how to connect / change lead positions for measuring voltage or current
• leave the boat on shore power, batteries charging, all consumption (fridge...) off
• return in a couple of days, measure voltage across battery terminals - this should be somewhere around 13.4V - 14.4V depending on your charger and if the battery is still accepting charge or the charger has reached the float charge state.
• if voltage is significantly below this, your charger may be defective, but it may as well be a completely dead battery consuming all the energy internally - check if the battery is hot, indicating possibly an "internal leak"
• disconnect shore power, wait a couple of minutes for the battery chemistry to settle down
• measure voltage accross battery terminals - this shoud be around 12.5V - 12.8V indicating at least 90% full battery - if less, your battery is not full, most likely never will be
• switch on navigation, steaming and anchor lights - assuming these are standard incandescent bulbs, you created a load of around 100W - corresponding to roughly 8A current
• measure voltage across battery terminals - this should now be around 12.3V - 12.5V - if less, your battery output is not enough, e.g. internal resistance is excessive due to aging
• if interested, you can now measure if the current truly is around 8A and you don't have any unanticipated consumption by connecting your multimeter in DC current measuring setup in series to the battery (=between battery positive terminal and the lead connecting to positive battery terminal)
• leave the lights on for 5hrs - now you have consumed 40Ah and should still have well >75% left of your battery bank
• switch off the navigation lights
• measure voltage across battery terminals - this should now be at least 12.3V indicating 70% of stated capacity still remaining - if less, your battery bank does not have enough capacity left

Hope this helps - but as stated above: the calendar age alone warrants for educated guess - you need to replace your original batteries.

BR,

Tommi

[Kibo]

...... I understand that keeping them constantly charging is a recipe for 'cooking' older batteries if they are not able to discharge from time to time. Could this be the cause of the apparent sudden collapse in battery health?
Cheers

Charger should have a feedback loop and controller so that once batteries are fully charged the charger switches off. If it doesn't then indeed over-charging will result and all batteries, not just old ones, will be fried.

Good advice from Tommi on checks to be made. I'm going to print that one out and laminate it next to my batteries for future reference

[Ianburtoncamera]

Nice one Tommi. Yes indeed Kibo that is great advice.

I think a battery change is in order. maybe add another leisure battery and have 3 leisure and 1 crank.

I hope it is just the batteries that need replacing and not the charger too.

looking online and maintenance free, deep cycle batteries range from about £60 to £250. are there any makes to avoid? Im struggling to find AGM batteries as suggested by Tiger79

[Kibo]

I have 4x 6V wired in series for the house bank. I am told 6V gives better balance of charge and discharge cycles. So called "Golf Cart "(or "Buggie" depending on US/UK English!) batteries is what they are generically called. I also have solar and wind generators too for top up. We live-aboard 4 months of the year so this is definitely worthwhile.

For stuff like this there are myriad recommendations and opinions; I tend to buy the median price ....... figuring cheap isn't worth it and expensive may be over priced, but that's just me. Others may have some better recommendations on makes and models.

[tiger79]

Im struggling to find AGM batteries as suggested by Tiger79

Try looking for Exide "Dual AGM" batteries, eg here - https://www.tayna.co.uk/Exide-Leisure-Batteries-S1254-1.html?ordering=&A-10=AGM

[Ianburtoncamera]

Thank you, they are expensive but I guess 'Buy Cheap, Buy Twice'

[Impavidus]

All.
I had a Bavaria 32 -2003 for 12 years. It was originally fitted with one Bosch 180ah on the domestic. As I added various electrical equipment such as Radar, twin plotters, inverter, I found that the battery life was much reduced. I then added a second lead acid flooded battery in parallel. Fine until I sold it in 2015. The charge splitter fitted to the boat from Bavaria was the diode type. These diodes have an internal resistance that cause a 0.5 volt drop through the splitter. Not much you may say but its enough to prevent full charging from the alternator.

I would recommend the Merlin alternator booster its pretty simple to fit but does require removal of the alternator and some soldering. The sense wire can then go to the domestic positive on the splitter on the battery side this overcome the volt drop and helps the alternator to achieve the correct voltage to fully charge the battery. the Merlin effectively turns you alternator in to a 5 stage charger adjusting the output from the field windings to give the fastest charge without damaging the battery.

Batteries will deteriorate with time. The cheapest may have 400 charge cycles and the more expensive may be 1000 cycles. But cold bad charging and over discharging will kill them quicker. Its not just down to the quality of the battery. all batteries will sulphate and this simply clogs the plates preventing the chemical reaction of charging and dis-charging from being fully effective. in short they loose their ability to hold the full charge.

I would recommend all boat owners to fit a battery desulfator and reconditioner like this one; http://www.ebay.co.uk/itm/252120721226?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
I used a Stirling version which worked well on the 32 they defiantly extend the life of your batteries by pulsing a high frequency (10,000Htz) through the battery(s) which breaks up the sulphate crystals.

Before you start to worry about chargers, test the battery. If its 5 years + old it will certainly be down to 60% of its stated capacity. Less if it has been heavily used, discharged below 40% of its capacity a few times or left at less than 75% charge for some time.

To test your battery it needs to have been fully charged and left to settle for at least and hour as described in the previous post. Voltage is not a good way to fully asses a batteries ability to provide power (amps) that's because the voltage can be high but the capacity low. you need to drop test the battery, apply a known load for a period of time to give you an indication of capacity.

You can use a drop tester. These are cheap say £30 or less from someone like machine mart (I have one if someone wants to borrow it) but better still is to apply a low load say 5 amps for 10 hours while measuring the voltage drop. The load should technically be adjusted as the voltage falls but for a simple test a 4-5 amp halogen headlamp bulb will probably do the trick or give you an indication of the capacity.

A new battery or one that's not old is not an indication of it's capacity. On my new Bavaria cruiser 37 (1 year old) I have had to scrap 2 of the Exide AGM batteries and replace them!! (£260.00 each). Even the de-sulphator would not bring them back. Exide batteries will not answer my mails or the two letters I have sent them. That should give you an indication of their belief in their product and why I will never buy another Exide battery.

I have replaced the two Exide withy AGM's from Ebay. 2 x 100 ah AGM's for £189.00 the pair.

My tips for long battery life would be;
You need twice the capacity you think you do.
Work out your daily consumption get twice the ah you use in your battery bank fitted
Get a NASA BM2 battery monitor with a 200 amp shunt fit it and keep an eye on your battery usage
Never discharge batteries below 11 volts or 50% of their capacity in ah
Use every opportunity to charge them
Get yourself a solar panel and use it (I have 2 x110 watt and they make a big difference)

I have an article half written on the woes of Batteries and the issues we had with them on Impavidus. I am just waiting a bit longer for a response from Exide or Bavaria before I publish.

There is lots of technical stuff I could add or explain but I have tried to keep it so the non electrical minded get an overview.
Hope this is useful


Ant.



 
     

         

[Salty]

For what it's worth, on my B36(2002), the 240volt battery charger was originally wired in with no switch to enable the charger to be turned off while the boat was plugged in to the shore. That has since been corrected, but a possible problem prior to my modification would have been that the batteries, as they got older and less efficient, were being continuously charged even when they did not need charging. This would result in them gassing off, and in the electrolyte becoming depleted and thereby reducing the capacity of the batteries as less and less of the internal plates remained immersed in the liquid. The batteries fitted were the original Bosch 140 A/H for the domestic services and a 100 A/H engine starting battery, and the cells were all accessible to enable the liquid levels to be checked. One can get battery rejuvenator pills from motor accessory stores, and whilst I was initially pretty sceptical about whether they would do any good or not, the cost of the pills was less than peanuts compared with the cost of new batteries. They worked, and as a result I got a further five years of battery life before going down with "I've got a get new battery fever" last year.
Also I'm entirely in agreement with Ant in his posting above regarding solar panels, though where to fit them can be a problem.

PS  One or two of the rejuvenator pills go into each battery cell, not down your own throat! 

[sy_Anniina]

Thanks Salty and Kibo, just realized one potential battery failure mode and root cause for my gassed / cracked sealed battery:

• Smart charger installed, this should cut charging from bulk (14.4V) to float (13.5V) when house bank is full = accepts no more charge
• Boat hooked to mains for a full week before a weekend cruise
• Fridge switched on - to keep the beer ready chilled 
• Fridge consumes power = charger sees current flowing in = maintains 14.4V bulk voltage
• At some point Batteries start gassing...

Getting ready to winter overhaul and planning on installing Nasa Battery Monitor along with new batteries next season. This should help me recognize when the batteries are full enough to cut the charging manually and prevent the chain of events above..

BR,

Tommi

[Salty]

And one other point, when the batteries start gassing, and as mentioned elsewhere within the forum, the hydrogen gasses coming off will also activate your carbon monoxide alarm if you have one fitted, despite that the gasses are not carbon monoxide.

What, you haven't got a CO alarm fitted ?? 

[Kibo]

And one other point, when the batteries start gassing, and as mentioned elsewhere within the forum, the hydrogen gasses coming off will also activate your carbon monoxide alarm if you have one fitted, despite that the gasses are not carbon monoxide.

What, you haven't got a CO alarm fitted ?? 

Mmmmmmm you've now given me new food for thought Salty. My CO alarm goes off very occasionally after motoring for a while. Its definitely not CO or Propane. I think I'll check my batteries to see if they re gassing significantly next time it happens.

[tiger79]

Thanks Salty and Kibo, just realized one potential battery failure mode and root cause for my gassed / cracked sealed battery:

• Smart charger installed, this should cut charging from bulk (14.4V) to float (13.5V) when house bank is full = accepts no more charge
• Boat hooked to mains for a full week before a weekend cruise
• Fridge switched on - to keep the beer ready chilled 
• Fridge consumes power = charger sees current flowing in = maintains 14.4V bulk voltage
• At some point Batteries start gassing...

Getting ready to winter overhaul and planning on installing Nasa Battery Monitor along with new batteries next season. This should help me recognize when the batteries are full enough to cut the charging manually and prevent the chain of events above..

BR,

Tommi

14.4v isn't enough to cause batteries to gas significantly, if at all.  Car batteries are subjected to 14.4v or more for hours on end without problems.

[Ianburtoncamera]

OK, just been told by an electrician that the batteries are not original to the boat from 15 years ago.

He said that they could be dead, but it sounds more like a charge issue from the engine, so I am going to ask him to have a poke about when I am next up there.

[Salty]

14.4v isn't enough to cause batteries to gas significantly, if at all.  Car batteries are subjected to 14.4v or more for hours on end without problems.

The odd few hours are not the problem, it's the boats that remain connected up to the mains with chargers operating for days, weeks and sometimes months while the owner is elsewhere. Yes, the charger, like those on cars, is supposed to go into float mode, just supplying enough current to keep the batteries topped up, but often as the threads in this forum have proved, what is supposed to happen very often doesn't.