Felshampo

Had a word with an electrician yesterday and have arranged for him to come and look at my system. You hit the nail on the head there Tony. I am out of my comfort zone here. I understand the advice being given and once someone shows me what to do I am fine but have limited knowledge of the systems on a narrowboat.

Soryy for being ambiguous. The generator is a beta marine installed one.

Thanks again Tony The charger is a MasterVolt combi 2500. So it could well be a split charger. Having talked to someone else about this they suggested that the generator could be charging the starter battery. Do they do this or just provide the 240v supply? If so that could account for the 14.4v.

I have AGM batteries which are supposed to float at 13.8v I think. I wondered if the going to float too soon was the problem also

I need to have an electrician look at this as I am not sure how to find out what set up I have. But thanks I now know what to ask and understand the effects.

OK. Still getting a reading of 14.4 to the starter and 13.8 to the domestic Bank. The monitor shows 31amps. Does this mean it is 14.4 for both? Shouldn't it automatically change over at some point?

I have just looked at the dip switches and they are bloody small but I think they are set for fixed float at 13. 8v. I have switched everything off and I am waiting for the mass combi to cool down and then I will change the dip switch. Why they were set like this I don't know unless the original owners were in a marina and plugged in all the time?

I have been looking in the manual and you can set the dip switches to give a constant float of 13.8v I wonder if this is the setting I have. Why would they be set like that? Is it easy to check the dip switches and if they are set up like that can I just change them?

I have just looked at the batteries this morning. They were at 12.4! I have put the generator on to charge them and I don't know why but I hadn't noticed this before. The starter battery is being charged at 14.2v but the home bank is being charged at 13.8v. The starter battery was at 12.8v this morning so didn't need to be charged really. I am know seriously worried that this has been the problem all along. Does anyone know what I should do to correct this?

As it happens .. no. I will try this next time....... Thanks.

Yes I read that. Before we had the new batteries that is what we got. How do you do a factory reset? The charger is showing the third and then the fourth LED. So both are absorption. I have got it to the first float LED a couple of weeks ago but that took about 8 hours and for half of that it was showing less than 10amps and 100% (I know)

The manual for the mastervolt reads as if all is preset with dip switches. I don't see how to change the charging voltage. Could the charger be using the float voltage? The manual is here https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.mastervolt.com/products/mass-combi-12v/mass-combi-12-2500-100-230-v/&ved=2ahUKEwiFvvXDt-biAhVTtnEKHctfC2EQFjAAegQIAxAB&usg=AOvVaw1Jdam_DAACcxzSTqFAve8k&cshid=1560428104826 I will check the charging voltage with the supplier

This morning the monitor read : 95% 85ah used 12.49v I switched everything off and waited about ten minutes and the voltage read 12.61v The toilet is still working today! I've got the mastervolt 12 / 2500 100 combi and the masterlink BTM III Thanks for everyone's help so far.

I have replaced AGM with AGM but I checked and the battery monitor is on Gel which is correct for AGM. The manual for the inverter/charger says the charging voltages are set. (in the software? ) I can do a factory reset of the battery monitor but not the charger, as far as I know, which should as you say be 14.4v. But the only way I know this is because that's what the monitor tells me. Should I do a factory reset of the monitor. The manual suggested I should wipe the battery history when installing new batteries - which I did.

I will switch everything off in the morning and check

Thanks WotEver. I have read this post, several times. And I actually understand some of it now! As I said above my mastervolt inverter charger shows 13.9v when in absorption mode since I had the new batteries. With the old batteries it was 14.4v. Any ideas why this is?

As I said above I have 6 x 160 ah batteries. That is 960ah. So I assumed (wrongly?) that once the amps were down to 10ish Amps the batteries were fully charged. So is it 2% of one battery eg 3.2amps or 2% of all six which is 18.2amps. I have left the charger on all day a couple of weeks ago to see what would happen and it went into float mode but still showed 4 amps. One thing I have noted is that the voltage showing on the battery monitor during absorption charging is 13.9v. Shouldn't it be 14.4v. I've also read that AGM batteries have different voltages when fully charged. Eg. 12.8 = 100% 12.6 = 75% 12.3 = 50%

So am I right in assuming that at the moment the voltage reading this morning of 12.5 v was under the resting reading because I still had the inverter on, fridge and maybe a couple of lights. If so how long do you wait after switching everything off to get a realistic reading? I have had the generator on for the past four hours and the charger was down to 10amps so I switched it off. I have waited an hour, switched every thing off and waited a few minutes and the reading is 12.8v.

OK. What about in the morning. If I switch everything off. Light fridge invertor etc. Will the mastervolt battery monitor give me a truer reading?

Yes I have read that before. I have got a chart of volts to % charged. OK. This is what I can explain. Batteries were charged by the engine for about 7 hours cruising yesterday. Monitor showed 100% (I know) Voltage was 13.9v We watched some TV and charged a couple of phones and had a 230v fridge on all the time. In the morning the monitor said 94%. 12.5v and 85ah used. We have 6 x 160ah AGM batteries. I have not got a multi meter with me, we are cruising, so can't measure resting volts. (or can I? I presume that is the reading with everything switched off) Fair enough

I thought that at first. But the electrician at North Kilworth marina said as they were AGM's they should have lasted longer. I have no idea how they had been treated. The one thing I do know is the mastervolt inverter was only a year old because the previous one had gone wrong. Apparently its almost cheaper to replace than repair them, something to do with the nearest service centre being in Holland? So the previous owner said. Anyway he gave me the receipt and the guarantee. So this could have damaged the batteries but like so much I know about the boat it's based on educated guesses.

I think they died and that's why they went down to 11volts. The new ones, which are used more than the old ones, are on 12.5 or more in the morning and that's with the temp higher so making the fridge work harder overnight (it's on the lowest setting before you ask). But I am still paranoid about batteries. I don't know if they were knackered when I got them or if they were OK and I killed them. Or if I treated them well but there is something wrong with my charger, generator, alternator or solar panel and one of them killed them. They were 7 years old but the boatyard that put in the new ones said they should have lasted 10 years or more.

Yep

Looked at the switch as that was my first thought and it's OK. But it doesn't turn on the water in the toilet. I wonder how that works. Is it a relay operated valve? Still wonder why switching on the generator cured the problem.

The batteries were showing 94% according to the MasterVolt battery monitor with a voltage of 12.5v. We never let them down much lower than this and charge them every day either through the engine or generator. I know I need a volt meter to test them properly across the terminals. Since the last lot died I am a bit paranoid about them. The water pump works fine as does the boiler, which was the first thing to stop working when the old batteries got flat. All the toilet switch does is open the tap into the toilet, I presume, because when it is on the water pump can be heard working. I tried the switch only a minute after putting the generator on so the batteries would still be low?