Yep agree with @Drover.
I suspect pulling them out and charging individually will bring them back to life, and then correcting the wiring will solve the charging issue.
I suspect pulling them out and charging individually will bring them back to life, and then correcting the wiring will solve the charging issue.
Hi @Boots in Action,
I agree with you
Hi @Drover,
I agree with you that from the photo the right battery would be getting more charge when the charge current is high. But eventually, once that battery gets charged its voltage will go up and eventually the second battery will get charged as well. The key word is 'eventually'.
Similarly, on discharge the right battery will deliver to most of the load. Especially when the load is high. But, again, eventually the voltage of that battery will go down and proportionally more of the load will come from the other battery.
I also agree with you that it is not ideal. However, I still suspect other things may also be wrong. But I might well be mistaken.
Here are my thoughts:
Firstly, it could be that some of the connections around the battery are actually dodgy.
Secondly, I don't know what size fuse is in the cable that joins the batteries together. If it has blown, then the second battery is not connected at all.
Thirdly, since the current coming from the solar panel, 7.5A, is roughly half of what I would expect, it could be that one panel is not connected properly or is faulty. Otherwise, the size of the cabling may be limiting what current can be delivered to the solar regulator and subsequently to the battery.
Fourthly, the batteries seem to be not being fully recharged by the Setec between trips. Since there is a week or more between trips, this seems quite odd. So, that also needs to be investigated.
You have just reminded me of something I missed. @aspiremr, when you remove the batteries, clearly mark which is left and right.
It is frustrating trying to sort this out from afar.
cheers
Mike
Hi @Bellbirdweb ,I think you are being a bit optimistic about full or even partial recovery of one or both batteries as it appears that they have been in a discharged state for some time and have only been partially charged if at all. I doubt that charging current seldom (if ever) caught up enough to increase the voltage for both batteries to carry the load, let alone put any guts into the system. Even the best deep cycle Gel or AGM batteries cannot handle long periods of draw down, and operating at low voltages without suffering some loss of power output!! It will be interesting to see what eventually unfolds, but I am putting my money on little or no ability to carry the loads currently being placed on it.
Hi @Drover and @mikerezny , I had a further look at the pictures and although not entirely clear, it looks like the heavy red Positive wire at the top left battery is the main feeder for input (from Setec??), and the heavy black wire after the shunt in right battery (centre) is the main Negative return. This is the correct way to charge two batteries in parallel. But only very thin wires create the parallel connection!!
However, the picture reveals that it is NOT connected correctly to spread the current and voltage for all the loads over both batteries!!. Also, the very light wires (both Pos and Neg parallel wires) would be highly resistive in transferring current across from one battery to the other as all the load points appear to have been looped off the battery on the right. Should be looped off Positive terminal on left battery.
Yes, @mikerezny is correct in saying that the battery voltage of two batteries in parallel will even out, if one battery cops most of the load because its electrical path to the load is the line with least resistance, but evening out the other battery to be the same as the charged/discharged battery will be prolonged and less efficient because of the high resistance in the thin wires linking them. What do you think about that @mikerezny ??
Also, if the in-line fuse on the pos in line (left battery) is gone, there would be NO charging current at all (from Setec??).The only current that would charge this left battery would come in via the right hand battery parallel line, which would receive current from fused solar input line (top right). That would mean that the left hand battery was never charged directly (with Setec) and only received charge via the parallel wire (thin) from the battery on the right. The battery on the right would carry the main proportion of the load AND receive the major portion initially of the output from the solar panels. The inline fuse for the solar (right battery at top) must be okay as @aspiremr says it is charging at 7 or so amperes. More grist to the mill in this great conundrum!! Comment from tech gurus would be helpful.
However, the picture reveals that it is NOT connected correctly to spread the current and voltage for all the loads over both batteries!!. Also, the very light wires (both Pos and Neg parallel wires) would be highly resistive in transferring current across from one battery to the other as all the load points appear to have been looped off the battery on the right. Should be looped off Positive terminal on left battery.
Yes, @mikerezny is correct in saying that the battery voltage of two batteries in parallel will even out, if one battery cops most of the load because its electrical path to the load is the line with least resistance, but evening out the other battery to be the same as the charged/discharged battery will be prolonged and less efficient because of the high resistance in the thin wires linking them. What do you think about that @mikerezny ??
Also, if the in-line fuse on the pos in line (left battery) is gone, there would be NO charging current at all (from Setec??).The only current that would charge this left battery would come in via the right hand battery parallel line, which would receive current from fused solar input line (top right). That would mean that the left hand battery was never charged directly (with Setec) and only received charge via the parallel wire (thin) from the battery on the right. The battery on the right would carry the main proportion of the load AND receive the major portion initially of the output from the solar panels. The inline fuse for the solar (right battery at top) must be okay as @aspiremr says it is charging at 7 or so amperes. More grist to the mill in this great conundrum!! Comment from tech gurus would be helpful.
Evening Gents,
About to sit down and re-read the thread from start to finish, and make notes about what I am going to try and do on Saturday.
But i can put one question to bed that I have seen. The fuse is a 40 A large blade fuse, and it is ok. A fuse blew in my 4wd compressor a few months ago and as a precaution I went and bought a spare fuse for all the fuse points I could find in all my toys, and in doing so that resulted in me checking this fuse.
One less variable for you all to ponder I hope. Whether 40A is good or bad I have no idea, but that is what is in there and it is working.
Thanks
MR
About to sit down and re-read the thread from start to finish, and make notes about what I am going to try and do on Saturday.
But i can put one question to bed that I have seen. The fuse is a 40 A large blade fuse, and it is ok. A fuse blew in my 4wd compressor a few months ago and as a precaution I went and bought a spare fuse for all the fuse points I could find in all my toys, and in doing so that resulted in me checking this fuse.
One less variable for you all to ponder I hope. Whether 40A is good or bad I have no idea, but that is what is in there and it is working.
Thanks
MR
Hi @Boots in Action,
if I am not mistaken, if the inline fuse above the left battery is blown, the left battery will be completely disconnected, it will not be charged or discharged.
cheers
Mike
I connected my external charger to both batteries last week while they were still in the van. I turned the battery bank off at the drifter panel. I then connected the external Ctek charger with one connection to the positive on one battery, and the other connector to the negative on the other battery.
The Ctek was able to recognise a circuit and charge both batteries My guess is if there was a blown fuse then the circuit would not have completed, but since it did and the batteries charged then the fuse between the batteries should be ok.
Am I on right track?
Hi @aspiremr , quick as a flash!! A good start, but did you check for continuity on the 40 A fuse with your multimeter?? Sometimes fuses "look" okay, but have actually blown. Just a thought. Whilst there, you could check voltage available with Setec switched on and solar panels disconnected. That will tell us if any power is coming in from Setec unit if voltage rises after Setec switched on.
Quite safe as no 240 V power there- should only be up to 14.05 volts.You do not have to remove fuse as you should be able to get probes of multimeter onto contacts at each side of fuse.
So if battery voltage BEFORE Setec is switched on is say 12.3 volts and rises to say 12.8 volts AFTER Setec is switched on, we at least know that Setec is putting "something" into batteries. Cheers
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Hi @aspiremr,
not exactly.
Assume the fuse is blown. Then, effectively, the red wire connecting the two batteries does not then exist.
Irrespective of where you put the -ve lead of the charger, the only battery that would receive a charge would be the one where you connected the +ve lead of the charger.
So, if the fuse is ok, as long as the +ve lead of the charger is connected to a +ve terminal of either battery and the -ve lead of your charger is connected to a -ve terminal of either battery, both batteries will be connected to the charger.
But if the fuse is blown, only one battery will be connected to the charger.
Does that make sense?
My suggestion to remove the batteries (labelling them so you know where they came from) and take them home was to greatly simplify things and allow you time during the week to just investigate the state of the batteries without the complexity of all the wiring in the van.
Once that is done, you will know the state of each of your batteries. As @Boots in Action has suggested, after this, you can still put these batteries back in the van to investigate if there are any other problems that need to be sorted with the rest of the gear in the van.
regards
Mike
Hi @aspiremr , if you put the positive of your charger onto the pos of the battery on the right and the neg of charger on neg of left battery, you would only be charging the right hand battery. There would be no current flow to the pos of left battery if fuse is blown. Ignore this if you used the POS on left battery and NEG on right battery.
Hi Mike,
Can I just check something please. Am working my way through all the threads to give myself a list to work through. In order to check the battery voltages with the multi meter, the battery would first need to be disconnected and isolated - is that correct?
So in working through the crazy readings from the Drifter panel from lats weekend, I would need to try all the same things I was doing last weekend, see what the drifter panel says, then isolate the batteries and use the multi-meter to take a comparative reading. Is that what you were suggesting above?
Hi @aspiremr, @Boots in Action, and @Drover,
I have had another look at the photo of the battery and found one very obvious wiring fault.
Look at the cable that is supposed to connect the two batteries together.
Now look carefully at where the black cable is connected on the Right battery. Actually look where it is NOT connected.
BOTH batteries should be wired in parallel: +ve to +ve and -ve to -ve. After that, a shunt is connected to the -ve terminals and all the -ve inputs and outputs should be connected to the other side of the shunt. i.e. Batteries on one side of the shunt, inputs and outputs on the other side.
So, the black wire coming from the -ve terminal of the Left battery should be connected directly to the -ve terminal of the Right battery.
It is clear from the photo that this is not the case.
This will have no impact on whether the Left battery is charged or discharged. BUT it will make a difference to the voltage drop across the shunt which in turn will be giving incorrect current readings on the drifter panel.
Any comments?
cheers
Mike
I have had another look at the photo of the battery and found one very obvious wiring fault.
Look at the cable that is supposed to connect the two batteries together.
Now look carefully at where the black cable is connected on the Right battery. Actually look where it is NOT connected.
BOTH batteries should be wired in parallel: +ve to +ve and -ve to -ve. After that, a shunt is connected to the -ve terminals and all the -ve inputs and outputs should be connected to the other side of the shunt. i.e. Batteries on one side of the shunt, inputs and outputs on the other side.
So, the black wire coming from the -ve terminal of the Left battery should be connected directly to the -ve terminal of the Right battery.
It is clear from the photo that this is not the case.
This will have no impact on whether the Left battery is charged or discharged. BUT it will make a difference to the voltage drop across the shunt which in turn will be giving incorrect current readings on the drifter panel.
Any comments?
cheers
Mike
HI @Boots in Action ,
I will definitely look really closely this weekend to determine if batteries are in series or parallel. Ive had a read of the Setec Manual. It is an ST35-III. It can provide 14.05v boost, 13.65v Float etc etc. Obviously that will never charge a 24volt system if it is fact wired in series.
I will take some much better photos.
This is almost a bit cool, I am starting to comprehend what the voltages mean and how they relate to the battery and system setup.
Thanks again everyone.
MR
Hi @aspiremr,
No, take all measurements without disturbing any of the existing wiring.
Ignore the USB problem. I explained what I think is causing this and a workaround in a later post.
The first step in fault finding is first to observe.
From observations, one looks for inconsistencies and attempts to consider things that could be the cause.
Then you perform experiments to prove / disprove what could be the cause. That is when you start the disconnecting and isolating.
Oops, sorry, but I have been fault finding for over 50 years. First time I ever actually wrote down how I go about it.
cheers
Mike
So @mikerezny , the shunt should not be connected inline between the cable that connects each of the negative terminals from each battery in parallel, but rather it should be in the negative cable leaving the batteries and heading off to the Caravan somewhere? And unless it is connected that way then any voltage readings on the Drifter panel will be unreliable - am i on the right track?
Thanks @mikerezny
If take a voltage measurement on one of the batteries using my multimeter, but the two batteries are connected, won't the reading be affected by the second battery? Or is that not how it works?