Battery Life

Hi,

What kind of Victron batteries?
Which charger? Is the charger correctly adjusted for the batteries? Overcharging with the wrong charger will kill the batteries.
Battery maintenance is an art!

I have exactly the same feeling about my AGM Victron 165 AH from year 2011.
We got a new charger installed and the installer did not put the settings via laptop for battery type etc, but I do not believe that this is the reason as they were not "cooked". Maximum charging is 14.5 Volt which is line for AGMs. Now the charger goes to absorption and float within minutes. As we have no shore power I can not use the float for a couple of hours to see if they fully charge.
After charging it shows 12.6 and falls to 12.4 within 20 minutes without load of course.

So I guess they are done. The bow and starter battery, also AGM seem to be fine.
We charge, by engine every weekend, several times when the engine is used. Maybe 4 to 6 times a weekend, maybe around 200 short cycles a year.

Any opinion would be appreciated.

HanaFe

If the settings on the charger are wrong (i.e. not for the right battery type), then 2 things will happen: it will shorten the life of the battery and you will likely not get the full charge from them. So, first thing to correct if it's wrong is the battery type settings. Then see what charge you get from them and lastly replace if necessary.

Note that any boat with a standard alternator/regulator (just like that used in a car) can only use lead-acid batteries. IF you want to use AGM, you need to install a smart charger or smart alternator or similar - Balmar has them, Sterling supplies different styles of converters as well. So if you're upgrading, do the whole system, not just the batteries. I have a 2007 400e and just continue to use rather inexpensive lead-acid (heavy duty, deep cycle) as they're a lot cheaper than the newer technologies. So far, I've got 4-5 years out of most of them....

good luck

These are the general principals as far as I understand.

Battery capacity always reduces over the course of time. If it is well looked after, it can last five years or more before either the capacity has reduced to an unacceptable level for house battery purposes, or it has insufficient power to turn the engine sufficiently fast for it to start.
The standard engine alternator will recharge the battery from 50 % to about 85% capacity in around two hours! but could take a further five hours plus for a further 10%. The reason is that the charge builds up on the battery plates surfaces and takes time to migrate into the plate. This "queue" fools the alternator into thinking that the battery is more charged than it actually is, so it reduces the amount of charge and the battery never actually attains full charge. When a battery is not fully charged, it sulphates, which is a coating on the plates which hardens over time and prevents any charge going into the plates. Therefore the progression of never being fully charged and and increasing sulphates gradually reduces capacity. A smart charger overcomes the "queue" to a large extent and also the soft sulphates before they become too hard, but battery capacity will reduce over time but not to the same extent over a given period. Therefore, the advice would be to use a smart charger all the time; if this is not possible, use one at least monthly; and make sure it is adjusted to give the correct charge for the battery type, as others have said.

Ersgill I am sure you 2011 yacht will have a smart charger connected when you are connected to shore power. You will need to read the manual to see that it has been set correctly for your batteries. If you really do have a much reduced capacity, it sounds as if your batteries may need replacing.

Do you have a battery monitor, which is a great help for monitoring batteries. If you do, you will notice that when you use the battery, it's capacity seems to fall very quickly initially and this is because the current is being taken from the surface of the plate and it then takes a while for the current within the plate to reach the surface - when you then stop drawing current, the battery capacity seemingly starts to increase because the current within the plate reaches the surface and equalises through the plate; you can then measure the actual battery capacity. When you recharge a battery, the converse is true, that is, you will only get an accurate state of charge if you let the battery rest for an hour or so.

Charles

Ok...... Let me weigh in here

We have a 2010 Hanse 400 with a yanmar engine 40hp, 30 amp Sterling charger, three vitron AGM batteries, one 60 am house and two 120 amp each for house, all factory installed. We purchased the boat in late 2012. I noticed then but didn't think it significant that the batteries would never charge to full capacity. Last summer while on a trip everything started to shut down. Eventually no power. Fortunaly the starter battery had a charge and we could get the engine going. We pulled the house batteries and had them checked professionally, both were toast! This was odd as they were virtually new. We replaced them and all seemed fine until at the end of the summer we noticed the batteries were again not charging the batteries to full capacity. I also noticed that the two red warning lights on the charger came on a short time after tuning it on. The manual indicated that the red lights signaled overcharging and overheating. Having installed new AGMs I felt strongly it was the charger. Of course the warranty had expired. We contacted Serling who were sympathetic and ask the charger be sent to them for analysis. We did and they said it tested fine and the red lights functioned as designed. I had a similar problem with a different Sterling charger on a different boat two years previous. They replaced that charger with a different type and all was fine. Unfortunatly, they declined this time as it was out of warranty. I am currently in the process of replacing the existing charger with one similar to the replacement charger on the other boat. The replacement charger is also a Sterling product. I am a little disappointed Sterling didn't replace the charger as I believe it is a manufacturer issue but I guess that is part of boat ownership and seasonal use. By the way my Hanse broker was great all through this and did what they could and more. I'll post the results next month after the new charger is installed and the boat is again in the water.

Tenacity

Edited by Nigel Fontaine - 24 March 2014 at 16:14