ROBDEN
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Posts posted by ROBDEN
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Where is this 0.7V drop of which you speak?
On the live side of an unused fuse holder, for a freezer.
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May I just drop this in.
!5.5v is needed at the batteries not the PDAR.
Yes I know.
I have a cunning plan!
PDAR battery sense(?) wire connects to a point where there is a voltage drop of about 0.6 or 0.7.
It then reads it as only 14.2v and 'tells' the alternator to kick it up to 14.9v. When in fact at the batteries it was 14.8/9v and goes up to 15.5v.
Rob....
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You really do need to be able to charge at 14.8 (or even a little more) and you really do need to be able to equalise by some means.
Trojans will need topping up now and again and this could be as often as once every couple of months, so reasonable access is required.
If you can meet these requirements then Trojans appear to me to be excellent for an off grid liveaboard boat.
They will take a fair bit of abuse too; they can cope with a some sulphation and still recover with a good equalisation. This is handy if you don't want to do a long engine/generator run every week.
..............Dave.
Thanks Dave.
I'm pretty sure I can trick the PDAR into giving out 15.5volts. Is that enough to equalise the batt's?
Rob....
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The only difference in charging requirements is that they like a high finishing voltage. The 14.9 you get is just perfect. Like any batteries they don't like repeated undercharging. There are lots of folk who CC off grid with Trojans, DMR is one for example.
That's good to know. Thanks for that.
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We've had 2 sets of ordinary wet leisure batteries on our boat. They both had very limited life and were what I would technically refer to as "rubbish". Not too surprising really as it seems this type of battery is effectively a rebadged starter battery.
We now have Trojan T105s and they are in a different league, definitely fit for purpose. I would never ever ever ever go back to ordinary leisure batteries! So that would be my recommendation.
Yeahbut. Thinking about them, I have the room but not sure I could meet their charging requirements. Ccing and no hook up.
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Looking at the voltages without the Sterling yesterday they did not exceed 14.5V. Now I am wondering why you changed the regulator and did you adjust the voltage on the regulator when you fitted it?
It was a gift and was in better condition than mine.
Left the voltage as per 'open lead acid' as it supposed to be the fastest charging.
This how the original one was set and did well for over 4 years.
Using this setting for sealed batteries was brought up on a thread here, a couple of years.
It was thought by many on this forum that all would be well and indeed there are a few members that do run like this.
It served me well on the last set of batteries.
How time flies. Found the invoice for the batt's. Not 4 months ago but 8 months.
Now thinking of getting new batteries but haven't decided which to go for yet.
Rob....
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Do you know what the maximum charging voltage was, with the old alternator controller?
Same as this one 14.8 - 14.9v. That's with the sense(?) wire on to the batteries.
But putting the wire on one certain point (with a voltage drop) I could get it to 15.2v.
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When was the sterling regulator installed?
Graham. Late to bed or up early?
I seem to be having a bit of a problem with internet signal at the moment so answers may be slow.
This one was fitted in late December but just replaced an earlier model that had been in use for about 5 years. Why?
Rob....
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As the information ties up with other knowledge I have I am quite happy with it. I asked for it from the company for Rob's sake so that he is not having to believe forum experts
Also I have an educated guess as to what caused the problems, but waiting for Rob to confirm something
Been out but back now.
Thanks for the info' Graham but what do you need me to confirm?
Rob....
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Restarted engine.
SG...86%
14.5 @33amps. After about 5 minutes back to 14.5 @0-1amp.
I'd better see if I can find the batteries' invoice.
Rob....
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Unfortunately those are the figures I would expect for a low capacity battery.
Ref the last reading that looks like something on the DC boats circuits is switching on, maybe a fridge or waterpump or the like and the charger is just adjusting to the demand.
I think it is unlikely that you will be able to see the water level in the battery, it depends on the construction and whether they have used a gel in a surrounding envelope etc. Do be careful if you do attempt to remove the battery top, there is acid and that battery will still have a lot of energy in it if shorted etc, safety glasses and clothing please
Oh if you see this in time. Stop charging wait 30 minutes and restart the charger and see what the figures are
Thanks for your concern Graham.
Just going to stop now.......back in 30.
Rob....
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Morning all.
This mornings strange charging figures.
The PDAR is disconnected.
SG reads 12.2v. 60%.
Engine run at 1000 revs
Start. 14.05. @62amps. SG….60%
+20 minutes. 14.2 @47amps
+20 minutes. 14.25 @35amps
+20 minutes. 14.5 @10amps
+20 minutes. 14.5 @2amps SG….76%
+20 minutes. 14.5 @ jumping between 3 and 8amps. SG….80%.
Still running.
Later today I’ll see if I can remove the top from one of the sealed batteries
to check the water level.
Rob.... -
Advanced Digital Alternator Regulator Pro Reg DW (waterproof) PDARWThe Sterling thingy will only reduce a portion of the recharge time. It can do nothing early in the cycle and then it has to decide how long it can safely boost the absorption charge voltage without damaging the batteries. It is likely to be conservative with that bit so will probably drop to float earlier than maybe it should. Just saying this so you are aware it may not be as effective as you think and seeing a float voltage may not mean the batteries are fully charged. (depends on which Sterling thingy).
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I feel like it
Rob did you take the voltage reading before you started charging?
12.25v.
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To get 440AH of batteries from 60% SoC to a tail current of 1-2A (less than 0.5% of capacity) should take many hours. Perhaps 8-10 hrs.
From 60% SoC the bank should be able to easily absorb the max alternator output for quite some time. But the OP reports 14.9v at only 63A after just 5 minutes. This is not normal battery behaviour, such a bank should take much more current at that voltage. In our case the current would only fall to 63A as the SoC was around 85%, and that would be at perhaps 14.2v.
These things point to either incorrect figures, or batteries seriously knackered.
We have had many such threads where the OP has disliked the Smartgauge reading. In every case that I can remember it has transpired that the SG has been correctly indicating a problem which the OP didn't really want to hear. I suggest this case is no different.
However, it shows that your batteries are way down on capacity, much less than 50%.
I DO NOT dislike the SG reading and if there is a problem I DO want to hear it. I am not an Ostrich!!
The whole idea of having the Sterling thingy is to reduce the charging time.
The next time I'm on 60% I'll disconnect the Sterling and using the same setting as today I'll see how
long it takes to get to 99%.
If I'm not satisfied I'll look into getting the batteries replaced (under the three year guarantee) Yeah right, or buy new ones.
Rob....
Rob
Sorry I lean with Nick, 60% of 440 is 264Ahs. to charge that in 2 1/2 hours the current would have to have been over 180A for an hour and then it would take more than an 1 1/2 hours to reach the 99%
Taking a blind guess say the average current was 50Amps for 1 hour (50Ahs) my educated guess is the batteries bank total capacity at this time is 250Ahs.
Sorry
Sorry?? Why? You haven't nicked my amps have you.
Rob....
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It's taken about 2.1/2 hours from 60% to SG now reading 99%@1-2amps.
So now (sod's law) SG and ammeter are about right correct?
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When I have finished this run, to about 1 or 2 amps, I'll set SG to 100% and see how the readings go then.
Rob....
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Like a lot of things about batteries it depends on exactly how you do them and control things. I would suggest that starting something like at 20% of capacity controlled by a good regulator which is battery sensing as the Sterling is the trade off is not much. With a lot of the older style regulators yes that would not be a good thing. However I would not recommended going above 20%.
Rob,
It is on that basis that I have said things seem set up OK for your batteries.
What are the batteries as a point of interest ?
Alphaline sealed calcium 110 amp.
Rob....
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It's what I did with the last set of batteries (same make and power) and they lasted over 4 years.
That's getting on for 1500 cycles....not too shabby I think.
Rob....
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The voltage and current readings you give here are more "believable" however you started at 60% SoC and within 5 minutes had 14.9v at 63A, that means the batteries are totally shagged. Perhaps as Graham said they are out of water. To confirm this, we are still missing the vital information which is roughly how long did it take to go from 60%SoC to the 1-3 Amps condition?
Basically what you are saying is correct in that once the current is down to 1-3A (presuming this is measured accurately) the batteries are fully charged. The Smartgauge tends to "see" the nature of the charger rather than the nature of the batteries during charge, and so it's charging algorithm is more along the lines of a voltage time integral, ie if you hold the voltage at X volts, starting from y SoC, it must be charged after z hours:minutes. However if the batteries are badly damaged this tends to not work very well. The designer was known to have said that the SG starts to not work well once batteries are damaged to below 50% of their original capacity, although in my experience it remains reasonable until well below this figure.
Have you noticed a significant reduction in the time it takes to get to the 1-3A condition and/or the SoC declining much more quickly than it used to? Both are indicative of knackered batteries.
Thanks for that. I'll let you know after this run.
Rob....
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This from post 13:- " Either way concerned the new batteries are seal and the old were floods and there could be battery damage and life shortening"
Not unless you used Graham's name for #13 or the forum screwed the names up.
I beg you pardon Tony.
Rob....
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This the same set up as my last set of batteries. They lasted over 4 years and were charged/discharged every day.
Batteries are sealed due to access.
Vetus 4.17 engine. 100 amp Iskra alternator with a Sterling reg' thingy on. ( Can get 100 amps at start up but have to rev to about 1400revs.)
Current measured with multi-meter and engine ammeter....both read the same.
SG fitted directly to battery posts.
I'll start the engine now and give you the readings.....back in a tick.
Right then. SG reads 12.25v/soc60.
Engine at 1000 revs. After 2 minutes 14.5v@78amps. After 5 minutes, 1000 revs, 14.8/14.9v@63 amps.
Anyway. What ever condition the batteries are in, if they can't take any more power ie: reading 1-3 amps, shouldn't the SG read 100% soc?
Regardless of whether 400 amps or 100 amps available?
Rob....
Rob,
My suggestion the next time you charge
Note the SG reading at the beginning of charge, end of charge and an hour or so later
Note the voltage at the battery if possible at start of charge, end of charge and an hour or so later
If the SG has not reset itself I would do a reset and watch for a repeat next time you charge
Sorry I do not understand your comment why would I need advice?
I think Tony has you confused with me......Bless.
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SG fitted about 5 years ago.
New batteries 4 months ago.
Voltage before charging was 12.25v.
Voltage an hour or two after charging (dark outside) 12.75-12.8.
Rob....
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I have 4 x 110amp batteries. They are charged via the alternator.
When charging starts, the alternator reads 14.8v-14-9v and about 80-90amps.
Over time this gradually drops to around 14.4 volts and the current drops to
1 - 3 amps. Fully charged?
After turning off the engine the SmartGauge is only showing about 80-85 soc.
Which is correct?
Should I just re-set the SG?
Thanks for any help/advice.
Rob….
Another Smartgauge question.
in Boat Equipment
Posted
Now comes the hardest part
That's what I will do but you asked where I found it.
Anyway. Now for the hardest part.....having to persuade SWMBO that we NEED Trojans.
Rob....