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Post by Deleted on Nov 22, 2018 13:35:54 GMT
No idea of the age of the batteries or what the previous charging regime was, other than boat based in marina on mains supply and told batteries fairly new (they look it).
Other issue is that with running engine at 15k revs I'm still only getting 13.8v (seems low to me), this is with everything turned off other than the fridge (which I currently havn't worked out how to turn off) - new flooring cover seems to have been added after the fridge was installed....
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Post by Deleted on Nov 22, 2018 13:42:44 GMT
Is it a vitrifrigo fridge? I've got one on one of my boats it has the compressor separate under the floor so its more efficient. Might explain why floor is disturbed. To turn off just wind the dial inside the fridge anticlockwise until it clicks. The dial on mine is to the right of the ice compartment.  . 13.8 with engine at 1500rpm sounds a bit low. I wonder if there is some sort of external regulator with a hot/cold battery temperature selector or something. |
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Post by Deleted on Nov 22, 2018 13:51:10 GMT
Is it a vitrifrigo fridge? I've got one on one of my boats it has the compressor separate under the floor so its more efficient. Might explain why floor is disturbed. To turn off just wind the dial inside the fridge anticlockwise until it clicks. The dial on mine is to the right of the ice compartment. . 13.8 with engine at 1500rpm sounds a bit low. I wonder if there is some sort of external regulator with a hot/cold battery temperature selector or something. Fairly standard fridge and have done what you said with the dial, no change as I'd already done that.
MPPT controller is showing no load and batteries at 25 c - shows this no matter what I do or how cold it is - something not right there.
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Post by Deleted on Nov 22, 2018 13:58:29 GMT
No idea of the age of the batteries or what the previous charging regime was, other than boat based in marina on mains supply and told batteries fairly new (they look it).
Other issue is that with running engine at 15k revs I'm still only getting 13.8v (seems low to me), this is with everything turned off other than the fridge (which I currently havn't worked out how to turn off) - new flooring cover seems to have been added after the fridge was installed....
That sounds like an older type alternator. Some batteries like to be charged higher than that and most modern alternators charge at 14.4 to 14.6 amps. Might not be a problem in your case though. |
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Post by Deleted on Nov 22, 2018 14:05:54 GMT
Only going off the paperwork...
Alternators 1 x 50 Amp + 1 x 70 Amp Domestic
Sterling Battery charger 120 watt
Boat built 2004
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Post by Telemachus on Nov 22, 2018 14:13:49 GMT
Right so at face value, you batteries are knackered. This presumes that it is a compressor fridge not an absorption / 3 way type. If it can’t run on gas and makes a faint whirring noise sometimes, it a compressor type.
We have 440AH of batteries and overnight, the fridge doesn’t really make a noticeable difference to them (after all, you are not opening the door etc).
Other points: yes if your alternator only gets to 13.8v that is inadequate for charging the batteries properly. Get that sorted (new alternator, or at least new regulator for it) before you get new batteries, otherwise the new batteries will be trashed rapidly. You want to be charging at 14.4v minimum, and whilst the difference might not sound a lot, the effect is big.
The MPPT controller only measures current from the panels into the boat (batteries and/or loads switched on). It doesn’t measure current coming out of batteries into the boat. The “Load” thing on most MPPT controllers is a separate output that isn’t used - it’s designed for servicing a separate load light a light etc.
The MPPT controller will probably have a remote temperature sensor plugged into it (sensor to be located at the batteries). If it’s showing 25C maybe the sensors isn’t plugged in /working. Or maybe your particular MPPT doesn’t have provision for remote temperature sensing and the software is using a default value.
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Post by Telemachus on Nov 22, 2018 14:18:27 GMT
Finally, if you are serious about batteries and keeping them in good health, get some monitoring equipment. OK yoir MPPT gives you battery voltage but you really need a means of measuring current in and out of the batteries and preferably State of Charge or at least amp-hour counting.
Electricity is invisible and without adequate monitoring equipment, you are just guessing in the dark.
Well it will be in the dark when the batteries go flat prematurely!
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Post by Deleted on Nov 22, 2018 14:24:43 GMT
I'm not familiar with the sterling alternator controller but does it have temperature sensing or a switch?
The only device I have which has a temperature switch is a very nice high quality older True charge 20i charger. It has a 3 way switch for cold warm hot batteries. The result of moving this switch is that the charging voltage changes a bit.
That's a 230v charger.
I agree with Nick that your batteries appear to be fekked.
I'd consider just two batteries rather than 4. But then I am a very low power consumer and keep my beer cold in what is known as a "shop".
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Post by Deleted on Nov 22, 2018 14:30:31 GMT
Right so at face value, you batteries are knackered. This presumes that it is a compressor fridge not an absorption / 3 way type. If it can’t run on gas and makes a faint whirring noise sometimes, it a compressor type. We have 440AH of batteries and overnight, the fridge doesn’t really make a noticeable difference to them (after all, you are not opening the door etc). Other points: yes if your alternator only gets to 13.8v that is inadequate for charging the batteries properly. Get that sorted (new alternator, or at least new regulator for it) before you get new batteries, otherwise the new batteries will be trashed rapidly. You want to be charging at 14.4v minimum, and whilst the difference might not sound a lot, the effect is big. The MPPT controller only measures current from the panels into the boat (batteries and/or loads switched on). It doesn’t measure current coming out of batteries into the boat. The “Load” thing on most MPPT controllers is a separate output that isn’t used - it’s designed for servicing a separate load light a light etc. The MPPT controller will probably have a remote temperature sensor plugged into it (sensor to be located at the batteries). If it’s showing 25C maybe the sensors isn’t plugged in /working. Or maybe your particular MPPT doesn’t have provision for remote temperature sensing and the software is using a default value. Many thanks for the reply.
A couple of questions;
1. Would it be sensible to try to sort out the assumed alternator problem first before replacing the batteries?
2. Is there something I could be doing wrong either physically or not monitoring the correct readout when charging?
Compressor fridge unless I've got things very wrong.
Please remember I'm a newby so could be making some very simple mistakes (i.e. MPPT controller currently switched to solar rather than Batt or Off).
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Post by Deleted on Nov 22, 2018 14:40:54 GMT
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Post by Telemachus on Nov 22, 2018 14:43:26 GMT
1/. Yes definitely, as per my reply!
2/. The MPPT will only show current coming from the panels, not from the alternator. As far as I can tell you don’t have any other monitoring equipment so you can’t know the alternator current (which is important for knowing when your batteries are full / when you can stop the engine). The MPPT voltage reading may or may not be accurate. Best to get a multimeter / clampmeter which you can put directly on the battery terminals when charging, and directly on the alternator terminals when charging, to check that the 13.8v problem is actually an alternator issue and not poor wiring (or inaccurate MPPT readout). I always recommend the clamp-meter UNI-T UT203 as this can measure dc current as well. Around £30 from eBay (careful with buying other clamp meters, many don’t measure dc current). The clampmeter can also measure the charging current, though of course this is less convenient than having a properly installed monitor.
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Post by Deleted on Nov 22, 2018 14:49:47 GMT
1/. Yes definitely, as per my reply! 2/. The MPPT will only show current coming from the panels, not from the alternator. As far as I can tell you don’t have any other monitoring equipment so you can’t know the alternator current (which is important for knowing when your batteries are full / when you can stop the engine). The MPPT voltage reading may or may not be accurate. Best to get a multimeter / clampmeter which you can put directly on the battery terminals when charging, and directly on the alternator terminals when charging, to check that the 13.8v problem is actually an alternator issue and not poor wiring (or inaccurate MPPT readout). I always recommend the clamp-meter UNI-T UT203 as this can measure dc current as well. Around £30 from eBay (careful with buying other clamp meters, many don’t measure dc current). The clampmeter can also measure the charging current, though of course this is less convenient than having a properly installed monitor. I have a multimeter/clamp meter KT200, just don't yet know how to use it! |
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Post by Deleted on Nov 22, 2018 14:54:47 GMT
Select dc amps, press the zeroing button then clip it over one if the main charge wires. Only one. If you do it over both then the result cancels itself like +1-1=0.
Clamp meters are great tools.
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Post by Deleted on Nov 22, 2018 14:59:39 GMT
Select dc amps, press the zeroing button then clip it over one if the main charge wires. Only one. If you do it over both then the result cancels itself like +1-1=0. Clamp meters are great tools. Apart from when you might possibly of bought the wrong tool...... |
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Post by Telemachus on Nov 22, 2018 15:03:22 GMT
Select dc amps, press the zeroing button then clip it over one if the main charge wires. Only one. If you do it over both then the result cancels itself like +1-1=0. Clamp meters are great tools. Apart from when you might possibly of bought the wrong tool...... You bought the wrong tool. The KT200 doesn’t do DC current, so pretty useless on a boat. Can you take it back? |
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