Lifepo4 problems

Submitted: Sunday, Feb 04, 2024 at 15:47
ThreadID: 146899 Views:1655 Replies:8 FollowUps:27
Long explanation, if you can last the distance and assist with advice (opinions?) it would be appreciated.

We have had 2 x 120ah Itechworld batteries for about 5 years now, running via an Enerdrive 40a dc2dc. Been a very reliable set up thus far. 100w & 120w panels on the rtt, plus recently added a Renogy 200w flexible (dc2dc Max 500w). Did a system check including all contacts about a month ago ready for 12 months travelling around WA.

4 nights ago a bit of a disaster occurred, could have become a major disaster. Could smell burning, like electrical wiring. Emptied the canopy and started checking everything. Turns out the shunt, which has been running fine all these years, had become damaged and one of the terminals cracked, became loose. This caused a poor connection, resulting in arcing and heating the wiring.

I have removed the shunt and connected the negative terminals directly via a 150a buss bar. All seems fine. I did notice the solar did not seem to be topping the batteries up as efficiently, but as it was a little cloudy I wasn't too concerned. Today it has been mostly cloudy. Placed portable panel in a reasonable position and went for a 2 hour walk. Got back and the battery voltage was at 11.8! I've had the panels in as much sun as possible and the batteries seem to be stabilising at 12. 8 but going no higher, even though the panels show to be putting in 4 to 9amps. Currently running just the 65l fridge.

Could the short have damaged the batteries (/bms)?

Sorry for the novel. Cheers, Mark.
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Reply By: Andrew L - Sunday, Feb 04, 2024 at 16:20

Sunday, Feb 04, 2024 at 16:20
If you have a multimeter, check each battery voltage independantly (remove earth to each when checking) if they are both showing voltage they are ok. Next start motor, and check dc to dc charging voltage. Lastly, check the solar is putting amps in by checking volts is rising. I am not sure what a shunt is, does it disconnect at low voltage?
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Reply By: Member - LeighW - Sunday, Feb 04, 2024 at 16:30

Sunday, Feb 04, 2024 at 16:30
You wouldn't have a short on the batteries if the shunt has gone open you have an open circuit between the batteries and the vans electrics. My concern would be without the batteries connected you could get high voltage pulses on the vans electrical system which could damage things like the TV etc or possibly the solar controller.

If you avarage out your guessed charging current then you get 7A, it is going to take a long time to put charge back into the batteries with a capacity of 240Ah and a 7A charge rate considering the fridge is runnint too.

May be nothing wrong, maybe just need more panels in the sun for a longer time.

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Reply By: RMD - Sunday, Feb 04, 2024 at 17:09

Sunday, Feb 04, 2024 at 17:09
G'day Mark.
As mentioned, you didn't have a short but a high resistance with current heating the site. Some regulators, ie most of them, say to connect the batteries first and then the solar. If yours has disconnected the batteries via a fault, then one or both regulators may be damaged.
Nothing has been shorted has it? The HEATING of wiring, is that localized at the shunt OR further away and fried wiring. If the terminals have been COOKED and you simply connected them together to bypass the shunt, they may still be a point of high resistance and will again cause heating of that site and restrict proper charging from happening as it should. CHECK those wiring connections/eyes for integrity!

To get some charge into the batteries, for a MONITORED SHORT WHILE, you could connect a panel DIRECTLY to the battery/s to see if the DC voltage pressure can deliver current to the batteries and begin raising their state of charge. Until the batteries get to near charged, the panel voltage will be locked to the level of the batteries as they rise and you can measure that easily. You cannot leave it like this though! It is just to get something into the batteries asap and confirm they are able to be charged. STOP when batteries get to around 14.2, no more. If at 14.2v they might then be around 80% charged.
Are you measuring the battery voltage with a Multimeter ? or are you relying on the info from the shunt system. Not sure what you have there or how it is giving information to you.
If no damage to regulators then something seems to be not quite correct with the repair you have done.

Is the 4 to 9 amps, panel current, or MPPT output current to batteries? Which system is that providing those figures?
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Reply By: Member - silkwood - Sunday, Feb 04, 2024 at 17:26

Sunday, Feb 04, 2024 at 17:26
Sorry for the delay in answering. I'm in a bush camp with intermittent service. I've been rechecking the system. Dc2dc is now showing 13.1. Batteries individually are showing 13.07/13.08.

Solar input showing 19v to dc2dc, 13.6 to the batteries. Vehicle currently (no pun intended) not connected (canopy on legs).

It appears the dc2dc is operating OK. I'll take the idea of connecting the portable solar directly, never thought of that.

What worries me is that, cloudy or not, the system should have been fine for a couple of days or more with no input.

Thanks for the ideas. I'll simply have to see how it goes for the next day (in Esperance in a couple of days, can get it checked professionally then). Sorry about the incorrect terminology (short), as usual I know just enough to cause me problems!

Cheers, Mark
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Follow Up By: Gronk - Tuesday, Feb 06, 2024 at 20:51

Tuesday, Feb 06, 2024 at 20:51
The system MAY have been good enough for a couple of days…IF fully charged, but you said the batteries were down to 11.8 ?
Don’t connect the unregulated solar now, as it appears as though your batts are charged.
What was the shunt for ? Does it supply a monitor ? If so, that monitor will not work properly, but the rest of the system should be ok.
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Reply By: Iano - Monday, Feb 05, 2024 at 00:35

Monday, Feb 05, 2024 at 00:35
I'm no expert, but the shunt damage might have affected the charging efficiency. Have you checked the BMS?
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Reply By: Batt's - Monday, Feb 05, 2024 at 01:36

Monday, Feb 05, 2024 at 01:36
I don't know how your system is set up but on my renogy set up the monitor is plugged into the shunt and every earth wire even the solar earth is connected to the shunt. That way the monitor knows what power is coming in and going out to get the correct percentage of the battery. If I added solar directly to the battery the monitor wouldn't recognize it so I wouldn't get a true reading of what percentage the battery is at just something to keep an eye on if yours does the same.
That's one of the faults I've found with lithium batteries. Also when mine shut down in the cold weather last yr I had no idea what the real percentage of the battery was when I woke it up back up.
I had a fridge running of it and I had no idea how long ago the bms went into sleep mode. When I got back home weeks later I put it on a 240v charger then was able to manually reset the percentage to 100% again. Little things you don't know about till it pops up unexpectedly.
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Reply By: qldcamper - Monday, Feb 05, 2024 at 09:48

Monday, Feb 05, 2024 at 09:48
Pick yourself up a small UNI-T multimeter with a DC clamp. Cheap as chips and suprisingly accurate.
With it you will be able to quickly see what current is flowing where and in what direction.
There is nothing complicated about charging and discharging batteries until you introduce all the expensive un necessary crap people are convinced they need because of the confusion created by lithium batteries.
Lithium batteries are simply not suited for what people need for travelling other than their weight savings. If you need thousands of dollars worth of gadgets to charge and monitor a battery that costs thousands of dollars to me means the wrong choice of battery.
On top of that it is usually the expensive monitoring equipment that fails.
Until auto manufacturers start designing their electrical systems specifically for lithium batteries it will always be a problem.
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Follow Up By: RMD - Monday, Feb 05, 2024 at 10:57

Monday, Feb 05, 2024 at 10:57
I agree with QLD on the buying and using of a multimeter which has a dc clamp function so you can monitor current flows in various parts of the system. The shunt systems seem to measure electrons of charge, in and out, but are not really accurate and sometimes need resetting when battery fully charged, otherwise a loss of accuracy is present. A simple volt meter which has at least a 4000 count screen will show the voltage and decimal points of that voltage , ie, 13,54 v or down near 12.82 v (example only), so you then know the state of charge according to manufacturers of battery specs.
Advantage with lithium s you can have more usable charge in the same AH battery and the weight saving mentioned.
To me, having a good regulator charging the battery and ability to see when required, the ACTUAL decimal point amounts of that voltage of the battery is about all I need.
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Follow Up By: Batt's - Monday, Feb 05, 2024 at 15:21

Monday, Feb 05, 2024 at 15:21
Why are lithium batteries not suited for what people need when traveling ?
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Follow Up By: qldcamper - Monday, Feb 05, 2024 at 15:40

Monday, Feb 05, 2024 at 15:40
I consider anything that needs a complex management systems unsuitable.
Pre packaged LPO batteries come with their own management system. Put two of them in parrallel then you have two management systems and then put a third in series with both of them starts to sound like something that isn't fit for purpose in the automotive platform.
To me anything to do with automotive should be drop in.
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Follow Up By: SCUBADOO - Monday, Feb 05, 2024 at 16:57

Monday, Feb 05, 2024 at 16:57
In the meantime we will continue to use our 4 cell 300Ah Sinopoly LiFePO4 battery pack to both power the motorhome and start the 3.9l turbo diesel engine often multiple times a day.

It has survived 10 years of full-time travel without a single issue.

Nothing new about LFP batteries.
Our "expensive" "BMS" consists of ensuring no charge source exceeds 14.1V, Victron SmartShunt battery monitor and a Victron BatteryProtect set to disconnect the battery at 12.8V.
Never triggered.

Lead acid will never be in our equation again.
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Follow Up By: qldcamper - Monday, Feb 05, 2024 at 17:19

Monday, Feb 05, 2024 at 17:19
That's the way it should be Scoob, but no supplier will warrant a simple system like that and continue to convince people they need all the bells and whistles.
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Follow Up By: Batt's - Tuesday, Feb 06, 2024 at 00:52

Tuesday, Feb 06, 2024 at 00:52
So qldcamper scubadoo's system is the same as most with the bells and whistles it has a monitor and shunt not a drop in and it's simple hey.
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Follow Up By: qldcamper - Tuesday, Feb 06, 2024 at 07:21

Tuesday, Feb 06, 2024 at 07:21
From memory his system consists of four prismatic cells with no battery management system, and connected directly to the starter motor, with nothing limiting the charge rate, only a low voltage cut out, no individule cell monitoring, no cell balancing, no hi or lo temp protection, so yes a lot simpler than anything comercial. And as he says the low voltage cut out has never activated.
Also, I cant remember the type of vehicle he has but willing to bet the cells are not mounted in the engine compartment where most 4wd vehicles have their starting batteries.
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Follow Up By: Member - LeighW - Tuesday, Feb 06, 2024 at 10:58

Tuesday, Feb 06, 2024 at 10:58
To be fair, my camper was originally supplied with two gel batteries, the charging was done by a solar panel, an AC charger and a solar controller. The solar controller has overvoltage protection, undervoltage protection and Ah monitoring. Does this sound familiar, yes it is basically the same as a Lithium setup. No fancy cell balancing you say, wrong the chargers timed absorption stage acheived the required cell balancing.

My replacement Lithium setup, two 100Ah Lithium cell packs, a BMS for over/under volts, this was installed as the current chargers didn't allow the voltage trigger points to be set and I wanted different trigger points. With current chargers available I wouldn't have needed a seperate BMS as the chargers would do the job.

Now looking at a car, the lead acids BMS is the alternator, alternators have the draw backs though, many don't hae overvoltage protection so if the voltage regulator fails it can boil the battery. Until smart alternators they didn't have a proper charging cycle and of course no battery under voltage protection so you would kill the battery if you left something turned on. These were compromises to save costs.

In my cars aux setup I had a VSR, a lead acid aux and a low voltage cutout. I replaced the lead acid by opening opening the bonnet, removing the lead acid battery and dropping in the Lithium, and that could have been that. I could have removed the low voltage cutout as the Lithium has that in built but I left it there anyway. I had always wanted a battery monitor to monitor the Ah in and out of the battery so I installed a battery monitor too. Of course now the latest version of the battery I installed has a battery monitor inbuilt so if installing the battery today I wouldn't have needed to the install the monitor. What happens inside the battery I don't care as I have no control over it and it does what it needs to do.

Lead acids also have basic battery managers, ie sealed battery have venting valves to control gas build up. Refillables have anti explosing caps etc, they have what is needed for safe battery operation same as Lithiums.

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Follow Up By: qldcamper - Tuesday, Feb 06, 2024 at 12:08

Tuesday, Feb 06, 2024 at 12:08
Leigh,
An alternators over voltage protection is the regulator.
All advancements in alternator control has been primarily for economy figures and alternator protection.
The engineers dont care about battery longitivity as long as it has enough in it to start the engine.
VRLA batteries is not a type of battery management, it's a safety device, a fancy term thought up by marketing teams, nothing more than a pressure valve that all sealed batteries must have.
I wouldn't call an absorption stage of a multi stage charger a cell balancing device either, chargers stay in absorption mode till the current drops below a preset level. Has no bearing what so ever on cell condition or state of charge, once one cell is fully charged and restricts the current flow the charger will change into float.
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Follow Up By: Member - LeighW - Tuesday, Feb 06, 2024 at 13:16

Tuesday, Feb 06, 2024 at 13:16
Cheap chargers switch to float when the battery voltage rises to a predetermined level and the current drops to a preset value. Better chargers have a timed equaliser stage that kicks in after the constant voltage stage to allow the cells to equalise. The charge voltages drops to a lower level for the duration of the timer setting. Some of the more upmarket models have adaptive equailsation charging and actually track how many cycles a battery has done and the depth of discharge and charge and adjust the timed absorption charge accordingly to operate daily weekly or whatever it determines is required.

From a chargers manual:

"Equailze charging voltage = 14.1V, charging will continue for the duration of the time set to equalise the cells, duration 0~180 min"

Some also have a boost charge setting which is used to stir up the electrolyte in flooded cells to stop stratification within a cell.

Over voltage protection is just that, a normal alternator regulator does not have overvoltage protection it regulates at the set voltage, if the regulator fails and the voltage goes higher than normal there is no overvoltage protection circuit to shut the alternator down in most cases. In an automotive environment the manfacturer has opted that it is better to kill the battery than to disable the car assuming the overvoltage situation doesn't kill the cars electronics. For aux batteries it is smarter to disconnect the battery then to kill it.

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Follow Up By: qldcamper - Tuesday, Feb 06, 2024 at 16:06

Tuesday, Feb 06, 2024 at 16:06
Exactly my point,
If you need to buy an expensive battery charger to maintain a battery in an automotive environment then the battery is not suited.
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Follow Up By: Member - LeighW - Tuesday, Feb 06, 2024 at 18:24

Tuesday, Feb 06, 2024 at 18:24
Hmm, your alternator is an expensive battery charger, $1500 for my Toyota unit so you sort of shot yourself in the foot there. Lead acid batteries aren't really suited for an automotive environment either and weren't designed for that purpose, they were the only option they had when cars came along so that's what they used and they originally died a quick death. They gradually improved the charging systems and batteries to increase battery life to a point that was considered exceptable and they haven't really changed much since then, cost versus benefit.

Today they could use smart alternators to better look after the battery but they don't again it just isn't worth it as the battery will probably die from vibration, heat and abuse rather than incorrect charging. As you pointed out the only reason we have smart alternators now is for fuel savings and anti pollution reasons. They could also use Lithium batteries but again cost versus benefit, Lithiums are widely used in racing cars for example for the weight saving and high energy density and therefore justify the cost.

The hybrid vehicle I'm buying has a Lithium battery for the hybrid unit, again weight saving and high energy density. It has a lead acid for the 12V system, the battery is charged by the Hybrid system DCDC and the battery is in the back of the car so heat not an issue, they could have easily used a Lithium instead and no doubt it would have a much longer life than the lead acid they have used but they didn't and that would have purely been for costs reasons.

Looking from an aux battery perspsective again it is cost versus benefit, how many with daul battery systems directly charge their AGM's or other directly off the alternator and don't use a DCDC charger? Most will use a DCDC as they investment cost in AGM's is high and they want to maximise battery life so again cost versus benefit. The DCDC they choose would have been done on cost versus benefit, some will go for expensive units with many charging options, others will opt for more basic units to save costs and wear the possible reduced battery life.

My Lithium is charged directly off the alternator without any issues. I could have put a DCDC in to charge it but see no benefit in doing so. The alternators output voltage is within the batteries design specs and the car never runs long enough for no float stage to be an issue. The Lithium has lasted longer than any lead acid battery I have had installed in the same position and longer than any cranker I have had in the car too. Heat and vibration is likely to kill it before incorrect charging will same for any battery installed in a car.

A BMS in a Lithium is there as an extra layer of protection to protect an expensive investment no mattery how it is charged. Alternator voltage regulators can and do go faulty, same for AC and DC chargers. If you build the battery yourself then can either include a BMS or not it is up to you. With a lead acid the cost versus benefit is just not there to warrant one.



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Follow Up By: SCUBADOO - Tuesday, Feb 06, 2024 at 18:55

Tuesday, Feb 06, 2024 at 18:55
I have no doubt that alternator regulators can fail but our 100A rated Canter unit has now survived 14 years with the last 10 years of full time travel managing to deliver 70-80A at 14.1V until the LiFePO4 battery is all but full. No smoke yet.

My Victron BatteryProtect will supposedly disconnect at LV 12.8 or HV 16V.
I know of two internal battery BMS devices and a Rxxxy 60A DC-DC charger that all failed in less than 3 months use by letting out a little smoke.

For some reason I have more trust in our alternator regulator.
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Follow Up By: qldcamper - Tuesday, Feb 06, 2024 at 19:50

Tuesday, Feb 06, 2024 at 19:50
1500 for an alternator, really ?

You really need to find another supplier.
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Follow Up By: Member - LeighW - Tuesday, Feb 06, 2024 at 19:54

Tuesday, Feb 06, 2024 at 19:54
Acytually I'm wrong, I just checked Amanya and the price for an OEM alternator for my Toyota is $2,067.83.
They have come down in price I think they used to be $3000. Must have been the remanufactured item I was thinking of.

Current remanufactured from Toyota are around $850, wouldn't even think of buying a Chinese or other clone.

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Follow Up By: RMD - Tuesday, Feb 06, 2024 at 20:03

Tuesday, Feb 06, 2024 at 20:03
LeighW
Yes, Toyota new replacement alts are hideously expensive? For some reason. An alternator isn't a battery management system - it is simply a charger!
How many alt regs have you had go high in control voltage?
A hybrid Toyota battery replacement will be the most expensive lithium you will ever buy. I hope it has warranty. Fortunately Toyota's have a good reputation.
I saved $ 23,000 dollars on my battery replacement, I bought a petrol car.
Re vibes and heat on batteries, Most people NEVER seem to protect batteries from engine bay heat or provide a base pad which insulates from vibes. Nearly ALL simply fit and HOPE it lasts. Some simple measures will make sure any battery fitted in an engine bay CAN last longer if protected from heat and vibes.
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Follow Up By: Member - LeighW - Tuesday, Feb 06, 2024 at 20:31

Tuesday, Feb 06, 2024 at 20:31
They are expensive but then you get what you pay for. I have read of so many failures of cheap new non geniune units after a short time that I wouldn't even consider buying one. I have seen plenty of alternator voltage regulators go high and boil batteries, same as not charging at all but they are usually brushes or the overrun clutch unit and then you get the low charge due to blown rectifiers etc.

Have a look at the plethora of regulator assemblies an alternators for sale on Ebay etc. They can be very reliable but like anything they can and do fail.

Personnaly in my own vehicles I have only had two failures. One that failed went overvoltage blew the fuse to the battery and then vaporised the turn and stop light filaments as well as destroying the flasher can and car radio. The other just stop charging due to blown rectifers. One of my brothers also had his alternator go high, brought the car around and said it smelt funny, you could smell the acid as soon as you got near the car.

"A hybrid Toyota battery replacement will be the most expensive lithium you will ever buy"

You haven't priced a replacement battery for a Tesla!

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Follow Up By: qldcamper - Tuesday, Feb 06, 2024 at 21:07

Tuesday, Feb 06, 2024 at 21:07
Leigh, you speak as though you are in the trade yet you dont know how to source a genuine Denso alternator other than through the dealers.
Pretty much like most of your knowlege comes from hear say and Google.
At least that is what it seams like to me, and that is my opinion which I am allowed to have weather you argue or not.
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Follow Up By: Member - LeighW - Tuesday, Feb 06, 2024 at 21:25

Tuesday, Feb 06, 2024 at 21:25
And Vice Versa

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Follow Up By: RMD - Tuesday, Feb 06, 2024 at 21:34

Tuesday, Feb 06, 2024 at 21:34
LeighW
That fuse which blew, What Model and year Toyota was it? Just curious why there is a fuse there. My HJ61 had straight from alt to Battery, but I did have a fusible link failure in an early Corona which left the alt unconnected from the battery but still with the electrical system, That blew the ALT, Both Highbeam headlight filaments, Electronic Optical Ignition, Radio fuse, IC in wiper delay and some other stuff too. Not sure why Toyota made it that way to self destruct if the fusible link failed.

I know 80 series petrol alts were $1300 from the Katherine dealer in 2010. I have carried a bracket and a spare small alt to fit if needed, but now use three panels on the roof to supply battery and all electrics if needed in emergency. I made a small 25ccHonda engine to power a small alt and it will generate 15 amps to get things going f required.
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Follow Up By: Member - LeighW - Tuesday, Feb 06, 2024 at 21:46

Tuesday, Feb 06, 2024 at 21:46
The car involved was a Suzuki, yes having a fuse between the rest of the cars electrics and the battery was not well thought out.

Yep same here, my camper has solar on the roof, I can power the the cars electrics from the van if need as long as I keep the cars accessories turned on to a minium. If out and about without the camper then I have solar blankets I can setup if I need to put charge into the cars batteries to get back to base.

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Reply By: Member - silkwood - Wednesday, Feb 07, 2024 at 19:35

Wednesday, Feb 07, 2024 at 19:35
Thanks for the input all. In Esperance now, had the batteries checked, seemed fine (local battery agent didn't try to sell me new ones, miracles do happen??)

I'm now on 240 power, had the solar on for a day and a half and the batteries are showing 14.1..."FUL" as the controller puts it.

Taking the solar off tonight and leaving it for the next two days (only thing the batteries are running is charging a couple of phones).

Looking good so far. Will take the advice on the clamp meter (I've been planning to grab one) but might give the "philosophical" discussions following a miss (glad to have provided yet another opportunity for more banter!)

Cheers, Mark
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Follow Up By: RMD - Thursday, Feb 08, 2024 at 14:41

Thursday, Feb 08, 2024 at 14:41
Silkwood
So the heading should have been, Flat batteries and burnt component problems. It appears there was NO LITHIUM problem at all.
Until you added more solar energy the shunt must have been able to "take it" but after more current flow through shunt connections the problem began.
My SiL had a solar house system fitted and the Foreign gentlemen fitting the system, installed a breaker of the same rating as system dc current. System stopped output, I looked see, and the internals of the circuit breaker were absolutely fried. The termination points of wires to breaker became illuminated.
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Follow Up By: Member - silkwood - Thursday, Feb 08, 2024 at 21:04

Thursday, Feb 08, 2024 at 21:04
Not quite, RMD. The heading was correct in that I had a problem with the batteries which may or may not end up being an issue resulting in battery failure. Luckily is was not. Hindsight is a wonderful thing...

As for the shunt "taking it", no, the shunt failed physically. I can see no connection between that failure and the increase in solar input. Interesting that you can...

Cheers,

Mark.
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Follow Up By: Allan B (Sunshine Coast) - Friday, Feb 09, 2024 at 09:48

Friday, Feb 09, 2024 at 09:48
.
Hi Mark,
Semantics aside, what I do find interesting is your statement that the shunt .. "had become damaged and one of the terminals cracked, became loose."
Certainly, if a shunt terminal "became loose" then it could generate heat and the system voltage could rise due to charging input with no battery load. But my concern is about the "terminal cracked" expression. A shunt for this application should look like the photo below where the cables are solidly bolted to the brass blocks at each end of the shunt element. There is nothing in the clamping path to "crack". Unless of course the shunt was a "cheapie" and constructed such that there was plastic in the clamping path. I have never seen such but anything is possible out of china!
Can you amplify on how the shunt was constructed and how it actually failed? Your explanation may be good advice to others.
Cheers
Allan

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Follow Up By: Member - silkwood - Friday, Feb 09, 2024 at 18:50

Friday, Feb 09, 2024 at 18:50
Alan, you are correct. It turned out to be a poor construction in which the lower nut on one side had metal tabs holding it in place to stop it turning. One of these are what snapped. Similar to the unit in your image, but not exactly the same. Unfortunately this construction was not apparent when the unit was in situ.

I wish I had thought to get a photo but I simply threw it away in disgust. Unfortunately I can't remember the brand (purchased 5 years ago) but it was recommended by someone who had it in place for over a year.

Cheers, Mark
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Follow Up By: Allan B (Sunshine Coast) - Friday, Feb 09, 2024 at 19:12

Friday, Feb 09, 2024 at 19:12
.
Mark, as the studs securing the current-carrying cables need to be well tightened in order to obtain a low resistance connection, it is advisable with this type of shunt to restrain the brass block with some form of spanner whilst tightening the terminal studs. As these brass blocks are not manufactured to suit standard open-ended spanner sizes I always use an adjustable wrench tightened down to grip the block while tightening the stud with a spanner or socket. This method avoids placing strain on the shunt's measuring element or the brass posts on the insulating base.
It should be noted that any distortion of the shunt element will result in a change to its resistance and therefore an error in the reading accuracy.
Good luck with getting it permanently sorted.
Cheers
Allan

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