My son who lives in Canberra bought a 2nd hand (2years old) Jayco Eagle recently. He found last weekend that while the sub was out, his battery was discharging. I suggested he may have a blown fuse, a dodgy joint somewhere.
Today he did some testing including wriggling some wires & found that he was getting (in full sun):a charge of 4A. I would have thought it should be a bit higher but knowing Canberra to be a little cool at this time of the year & the panel is mounted flat on the roof, should he be expecting to see around double that charge?
Are there any other members who live in Canberra & who may have the optional solar/lithium power set up on their Jayco Caravan. It seems to be a standard set up.
The solar panel is 180w, the BMPRO is J35, model B-L. The previous owners were unable to tell him much about the unit, they hadn't used it much & were just interested in recouping some of their lost cash.
Warren-Pat_01 said
11:44 PM Aug 3, 2024
I had a text conversation with him tonight - mentioned that it's important to measure the battery voltage, any charge current before he starts, then after. He said the panel was dirty & has cleaned it.
The battery is a 100Ahr lithium - I'm hoping the previous owners didn't just pack it away without maintaining some sort of a charge. Do lithium batteries suffer similarly to AGMs if not properly maintained?
We had a similar experience when we bought our Eagle - the owners just charged it when they were going to use it - with the Jayco 5A charger!! The battery was stuffed, terminal voltage was 3.5v!!
Dick0 said
11:28 AM Aug 4, 2024
Lithium battery is not normally stuffed at 3.5V, it's below the charging threshold of 10.5V for most chargers and BMS.
Check youtube how to charge a depleted Lithium battery.
AGM batteries should not be depleted below 50% in normal use to retain efficiency. Lithium can be depleted over many, many cycles and still remain efficient.
Peter_n_Margaret said
11:31 AM Aug 4, 2024
Dick0 wrote:
AGM batteries should not be depleted below 50% in normal use to retain efficiency.
Cycles is not a measure of the lifetime energy delivered from a battery because the cycles are not the same size.
I have not watched your video, I consult the manufacturers who have proper data. (See Fullriver data attached)
See the lifetime cycles for various depths of discharge and then convert those to Ahr actual energy delivered.
Just in case you don't want to do it yourself, it looks something like this.... (based on a 100Ah battery)....
30% DOD = 1420 cycles x 30Ah per cycle = 42,600 Ah total life.
50% DOD = 650 cycles x 50Ah per cycle = 32,500 Ah total life.
70% DOD = 450 cycles x 70Ah per cycle = 31,500 Ah total life.
100% DOD = 280 cycles x 100Ah per cycle = 28,000 Ah total life. (about 7% less than 50%).
(ps - 100% DOD is defined as 10.5V)
And of course, if you restrict the DOD, you need to carry more batteries (which weigh more and cost more, but need replacing less frequently).
And if you restrict your DOD to zero, they last forever. :) But they don't of course, because there is a time based deterioration as well. So there is a
good argument for working your batteries hard and replacing them more often. And the bloke (including me) who says "My batteries lasted for 9
years" means absolutely nothing.
Cheers,
Peter
EDIT: Of course, EXACTLY the same applies to Lithium batteries, except the numbers are bigger.
-- Edited by Peter_n_Margaret on Sunday 4th of August 2024 01:22:57 PM
-- Edited by Peter_n_Margaret on Sunday 4th of August 2024 01:25:34 PM
Cycles is not a measure of the lifetime energy delivered from a battery because the cycles are not the same size.
I have not watched your video, I consult the manufacturers who have proper data. (See Fullriver data attached)
See the lifetime cycles for various depths of discharge and then convert those to Ahr actual energy delivered.
Just in case you don't want to do it yourself, it looks something like this.... (based on a 100Ah battery)....
30% DOD = 1420 cycles x 30Ah per cycle = 42,600 Ah total life.
50% DOD = 650 cycles x 50Ah per cycle = 32,500 Ah total life.
70% DOD = 450 cycles x 70Ah per cycle = 31,500 Ah total life.
100% DOD = 280 cycles x 100Ah per cycle = 28,000 Ah total life. (about 7% less than 50%).
(ps - 100% DOD is defined as 10.5V)
And of course, if you restrict the DOD, you need to carry more batteries (which weigh more and cost more, but need replacing less frequently).
And if you restrict your DOD to zero, they last forever. :) But they don't of course, because there is a time based deterioration as well. So there is a
good argument for working your batteries hard and replacing them more often. And the bloke (including me) who says "My batteries lasted for 9
years" means absolutely nothing.
Cheers,
Peter
EDIT: Of course, EXACTLY the same applies to Lithium batteries, except the numbers are bigger.
-- Edited by Peter_n_Margaret on Sunday 4th of August 2024 01:22:57 PM
-- Edited by Peter_n_Margaret on Sunday 4th of August 2024 01:25:34 PM
Don't tell me as it is not my opinion, watch the videos and tell those in the business giving the advice.
The lower and the often the battery DOD the quicker the battery will deteriorate. And that is not my "opinion".
-- Edited by Dick0 on Sunday 4th of August 2024 06:02:17 PM
Peter_n_Margaret said
05:59 PM Aug 4, 2024
The video counts cycles, not power provided. In terms of what a battery is purchased to do, this is a complete nonsense.
Cheers,
Peter
Dick0 said
06:04 PM Aug 4, 2024
Peter_n_Margaret wrote:
The video counts cycles, not power provided. In terms of what a battery is purchased to do, this is a complete nonsense. Cheers, Peter
Don't tell me as it is not my opinion, watch the videos and tell those in the business giving the advice.
The lower and the often the battery DOD the quicker the battery will deteriorate. And that is not my "opinion".
If you have inclement weather use the battery's full capacity. That is what it is there for. In you do this once a month over five years it's only 60 cycles. It will barely make any difference.
Dick0 said
07:23 PM Aug 4, 2024
Peter_n_Margaret wrote:
Dick0 wrote:
Don't tell me as it is not my opinion, watch the videos and tell those in the business giving the advice.
The lower and the often the battery DOD the quicker the battery will deteriorate. And that is not my "opinion".
If it is not your opinion, don't spread this misleading advice around.
The total energy that a battery can deliver in its whole life is not seriously affected by the depth of discharge that it is used at.
You can not measure a battery's ability to supply energy in cycles. Measure it in Watt hours (or Amp hours).
That is a fact backed up by manufacturer's data. Do you have any manufacturer's data (from any reputable manufacturer) that is different to that?
Cheers,
Peter
Watch the videos.
BarneyBDB said
09:54 PM Aug 4, 2024
Do people actually believe everything they see on U Tube???
TimTim said
10:25 PM Aug 4, 2024
Warren-Pat_01 wrote:
I had a text conversation with him tonight - mentioned that it's important to measure the battery voltage, any charge current before he starts, then after. He said the panel was dirty & has cleaned it.
The battery is a 100Ahr lithium - I'm hoping the previous owners didn't just pack it away without maintaining some sort of a charge. Do lithium batteries suffer similarly to AGMs if not properly maintained?
We had a similar experience when we bought our Eagle - the owners just charged it when they were going to use it - with the Jayco 5A charger!! The battery was stuffed, terminal voltage was 3.5v!!
The LiFePO4 battery may very well not be stuffed. It may very well have been drained down so that the BMS inside the battery activates the low voltage disconnect. When this happens you will still get the low voltage that you are seeing though the terminals but the actual cell voltage may well be higher.
If the battery will not charge using the solar controller or a battery charger then you need to do what we call a jump start.
Follow this link to get the battery out of safe mode.
My apologies as you will need to copy and paste the links. for some reason it has given up on me again.
To add to the above your BMPro should still charge the battery even if the BMS has shut down.
Heavily Discharged LiFePO4 Batteries (J35B-L / J35D) The J35B-L and J35D can recover and charge a heavily discharged LiFePO4 battery. The internal Battery Management System (BMS) of a LiFePO4 battery will turn off if it detects that the battery is heavily discharged. The J35B-L or J35D will provide the voltage to restart the LiFePO4 batterys BMS and then commence charging of the LiFePO4 battery
Tim
-- Edited by TimTim on Sunday 4th of August 2024 10:32:02 PM
-- Edited by TimTim on Sunday 4th of August 2024 10:57:24 PM
Scubadoo said
09:11 AM Aug 5, 2024
Warren
Hopefully you get that battery fully charged and up and running again soon.
-------------
BarneyBDB wrote:
Do people actually believe everything they see on U Tube???
Nope.
Our 4 cell 300Ah LiFePO4 battery has survived 10 years of fulltime travel and counting.
I can tell you plus or minus 1% the battery energy delivered in Wh or Ah.
I could not tell you plus or minus 80% the number of cycles it has been through.
Cycle counting in a typical RV setup is an impossible task and all but irrelevant anyway. It would require some consistency in daily energy use. Non existent here.
Dick0 said
11:10 AM Aug 5, 2024
TimTim wrote:
Warren-Pat_01 wrote:
I had a text conversation with him tonight - mentioned that it's important to measure the battery voltage, any charge current before he starts, then after. He said the panel was dirty & has cleaned it.
The battery is a 100Ahr lithium - I'm hoping the previous owners didn't just pack it away without maintaining some sort of a charge. Do lithium batteries suffer similarly to AGMs if not properly maintained?
We had a similar experience when we bought our Eagle - the owners just charged it when they were going to use it - with the Jayco 5A charger!! The battery was stuffed, terminal voltage was 3.5v!!
The LiFePO4 battery may very well not be stuffed. It may very well have been drained down so that the BMS inside the battery activates the low voltage disconnect. When this happens you will still get the low voltage that you are seeing though the terminals but the actual cell voltage may well be higher.
If the battery will not charge using the solar controller or a battery charger then you need to do what we call a jump start.
Follow this link to get the battery out of safe mode.
My apologies as you will need to copy and paste the links. for some reason it has given up on me again.
To add to the above your BMPro should still charge the battery even if the BMS has shut down.
Heavily Discharged LiFePO4 Batteries (J35B-L / J35D) The J35B-L and J35D can recover and charge a heavily discharged LiFePO4 battery. The internal Battery Management System (BMS) of a LiFePO4 battery will turn off if it detects that the battery is heavily discharged. The J35B-L or J35D will provide the voltage to restart the LiFePO4 batterys BMS and then commence charging of the LiFePO4 battery
Tim
-- Edited by TimTim on Sunday 4th of August 2024 10:32:02 PM
-- Edited by TimTim on Sunday 4th of August 2024 10:57:24 PM
Plenty of good stuff on youtube, just have to sort out the wheat from the chaff . The same in life in general.
Tim
Warren-Pat_01 said
07:48 PM Aug 12, 2024
Thanks for the replies chaps.
David my son, who knows little about technical items is slowly learning. A few years ago I gave him a multimeter for Christmas & wondered at the time whether I gave him something he would never use! It is now getting a work out.
After the first attempt at getting the battery to charge, he put it on to mains power & fully charged the battery, according to the app.
Last Saturday he had another go at it & borrowed a neighbour's solar blanket. He discovered that the flash controller wouldn't let anything flow into the battery until a certain discharge voltage was reached. It then woke up & proceeded to send 4.3A into the battery, Adding the blanket into the external charging plug on the camper have him another 4A. A while later the batter reached full charge (on the app)
So my question comes & I have more to read up on this system it seems, is why if the battery needs just over 8A to fully charge it again - why won't the 200w panel supply it (bearing in mind losses due to having a flat panel vs one raised at the correct angle)?
David is planning a trip on long service leave to WA soon, hopefully free camping where possible. It will try out both his wife & teenaged daughter who both are not campers!
TimTim said
09:20 PM Aug 12, 2024
Hi Warren,
Well you have shown us that your battery charges and there appears to be an issue with either your BMPro for solar charging or your solar panel, or maybe the connections between the two.
Have your son put the multi-meter on the + and - solar panel input terminals of the BMPro whilst the solar panel is in full sun and it should read around the 23V mark. I have sent you the link for the manual previously. But to be exact there will be a label on the back of the panel which tells you the Voc. The voltage should be close to that. If not then it will be time to test the connections in the cables if there are any or the connector box on the back of the solar panel. Also look for a fuse in the cable although you don't need one. You did say in your first post that wriggling the wires you did get current so it would seemlike a faulty connection somwhere.
https://www.youtube.com/shorts/oV8SnZJextc
https://www.youtube.com/watch?v=UnZ0-ZLm1KE
Good luck
Tim
-- Edited by TimTim on Monday 12th of August 2024 10:54:10 PM
TimTim said
11:56 AM Aug 13, 2024
Warren-Pat_01 wrote:
Thanks for the replies chaps. David my son, who knows little about technical items is slowly learning. A few years ago I gave him a multimeter for Christmas & wondered at the time whether I gave him something he would never use! It is now getting a work out.
After the first attempt at getting the battery to charge, he put it on to mains power & fully charged the battery, according to the app.
This shows that the battery is charging and that there are no issues with the battery.
Last Saturday he had another go at it & borrowed a neighbour's solar blanket. He discovered that the flash controller wouldn't let anything flow into the battery until a certain discharge voltage was reached. It then woke up & proceeded to send 4.3A into the battery, Adding the blanket into the external charging plug on the camper have him another 4A. A while later the batter reached full charge (on the app)
Im unsure what you mean when you say flash controller as to whether you mean the BMPro or the solar controller for the solar blanket. The solar blankets charger may not have been set for a LiFePO4 battery so when the charger is connected up it is already reading that the battery is fully charged.
A fully charged LiFePO4 battery is generally 14.6V but that is also dependent on the BMS inside the battery. When the charging stops the voltage at the terminals will drop to about 13.6V but the battery is still fully charged. If you reconnect the charger you will generally see current going in but only for a very short time, that is of course unless you are discharging as well.
So my question comes & I have more to read up on this system it seems, is why if the battery needs just over 8A to fully charge it again - why won't the 200w panel supply it (bearing in mind losses due to having a flat panel vs one raised at the correct angle)?
The battery does not need just over 8A to fully charge it again. The is just the current that is going into the battery at that particular moment. If he had watched closely for a short period he would see the current drop down to zero.
You have proved that the battery is charging on 240V and through another solar blanket (although you have not fully explained which solar controller) At this stage it would seem that the fault is in the wiring to your solar panel or the solar panel itself. Check all wiring connections and especially if you have Anderson plug connectors, in that case check that the contact pins are fully pushed into the plug and are locked in over the edge of the edge of the metal retainer clip.
David is planning a trip on long service leave to WA soon, hopefully free camping where possible. It will try out both his wife & teenaged daughter who both are not campers!
May be a good idea to get David to join the forum even if is only to solve this problem.
Good luck
Tim
Warren-Pat_01 said
07:25 PM Aug 14, 2024
Thanks Whenarewethere,
I cannot recall when I used Trigonometry calculations for working out angles, etc - perhaps it was around 40 years ago when several of us did a night school maths course to pass a qualification to become a Tech Officer within the then Telecom Australia (we all failed but the special course enabled us to know what the examiners were asking)!
And Tim, Getting back to your assistance, thank you also. My comment on the "Flash" controller meant the BMPro. The solar blanket did not have a controller fitted to it - it was fed into the "Unregulated Input" on the trailer - I assume it goes into one of the Auxillary inputs of the BMPro. We have had or planned trip to Canberra to house sit the animals while they are away & will if all goes well arrive before "Grandparents' Day" in late September. That will give me an opportunity to chase up what goes where & to do some testing myself, including utilising a dummy load on the battery. And it "might" give me an opportunity to find out something about the solar panel - which is mounted 15mm clear of the roof!!
I've tried to find out what panels Jayco use - it's not easy. The American ones use a panel made or sourced by "Go Power", here in Australia??? I'll check with a chap who works for Jayco Townsville to see if he can be of assistance. I had my son short out the panel with his meter on the 10A range & I recall him saying it was about 4A. That leads me to two issues - either there's not enough sun or there's a dudd joint somewhere from the panel to the BMPro.
(Our house had an issue when I had one of "Rudd's Dudds" install our solar system in 2011 - they used dissimilar connectors, water got in & caused arcing. We had Decramastic tiles on the roof at the time. If it hadn't been for a neighbour out mowing his lawn, smelling smoke & calling the fire brigade, we would have lost the house!)
watsea said
10:40 PM Aug 14, 2024
Warren,
Regarding the type and spec of the Jayco panel, I suggest that someone gets up, lifts the panel and takes a photo of the name plate and its specs.
I reckon Jayco do not always use the same make and specs for their vans. My van came with a notional 150 watt panel. Someone I know who had a similar and same year built Jayco van is fitted with a panel that is specified at 160 watts, though it is the same physical dimensions.
I added another 175watt panel to my roof. The same physical dimensions as the original panel, though a different brand.
I connected the panels in parallel circuit and tried to select the new panel with a similar voltage output for better efficiency of combined panel output, of course taking cost and perceived quality recommendations into account.
My apologies as you will need to copy and paste the links. for some reason it has given up on me again.
If one presses & holds for a second on your mobile phono, the link text which will then highlight in its entirety & the ask to open etc.
You do not need the text to be linked as such.
Brenda and Alan said
09:13 AM Aug 15, 2024
Warren-Pat_01 wrote:
I've tried to find out what panels Jayco use - it's not easy. The American ones use a panel made or sourced by "Go Power", here in Australia??? I'll check with a chap who works for Jayco Townsville to see if he can be of assistance. I had my son short out the panel with his meter on the 10A range & I recall him saying it was about 4A. That leads me to two issues - either there's not enough sun or there's a dudd joint somewhere from the panel to the BMPro.
Warren. As I see it the max current under ideal conditions from a 180 W panel would be less than 13 amps. In Canberra at this time of year I think you would be lucky to see 4 amp.
Alan
-- Edited by Brenda and Alan on Thursday 15th of August 2024 09:43:06 AM
Warren-Pat_01 said
02:48 PM Aug 17, 2024
I had another thought this morning. I think the battery might be fully charged as David said this morning when he removed the cover, the solar immediately started to charge at 1.3A. It was cloudy at the time, rained later. The app shows both charging & discharging voltages & currents but not the static - my understanding.
I'm going to add a Jaycar (or Temu - are these any good?) digital voltmeter controlled by a switch to the adjacent panel on the 'power cubicle' so the battery voltage can be seen easily.
I went to our local Jayco dealer on Thursday & found the current panels that are being installed (or since 2022) are Sphere 200w panels. According to RV Parts Express, these are quite reasonable panels & now are the same physical size as the previous 180w panels. I don't want to add any more to his roof as the cables that raise the roof have a nasty habit of breaking.
We are driving down to Canberra in mid September, so I'm looking at being able to do some better testing myself. This trying to do it remotely is a drama! Some say we should live closer - all very well but I can't cope with the cold nor the house prices down there!
Alan, thanks too for your assumption on Canberra's weather conditions for running solar. I know the sun there is far more scarce there than it is here in NQ!
TimTim said
10:59 PM Aug 17, 2024
Warren,
The voltage is not an accurate way of determining the state of charge of a LiFePO4 battery. This is because the the charge and discharge curve are very flat until they come to what we call the knee. If you look at the attached chart, which will only be an approximate, you can see that between 13.0V and 13.3V there is a 60% difference in the state of charge.
To get a more realistic SOC you will need a shunt which you can either get with a display or Bluetooth.
Cycles is not a measure of the lifetime energy delivered from a battery because the cycles are not the same size.
I have not watched your video, I consult the manufacturers who have proper data. (See Fullriver data attached)
See the lifetime cycles for various depths of discharge and then convert those to Ahr actual energy delivered.
Just in case you don't want to do it yourself, it looks something like this.... (based on a 100Ah battery)....
30% DOD = 1420 cycles x 30Ah per cycle = 42,600 Ah total life.
50% DOD = 650 cycles x 50Ah per cycle = 32,500 Ah total life.
70% DOD = 450 cycles x 70Ah per cycle = 31,500 Ah total life.
100% DOD = 280 cycles x 100Ah per cycle = 28,000 Ah total life. (about 7% less than 50%).
(ps - 100% DOD is defined as 10.5V)
And of course, if you restrict the DOD, you need to carry more batteries (which weigh more and cost more, but need replacing less frequently).
And if you restrict your DOD to zero, they last forever. :) But they don't of course, because there is a time based deterioration as well. So there is a
good argument for working your batteries hard and replacing them more often. And the bloke (including me) who says "My batteries lasted for 9
years" means absolutely nothing.
Cheers,
Peter
EDIT: Of course, EXACTLY the same applies to Lithium batteries, except the numbers are bigger.
This post is very dogmatic and unsound, all you have done is repeat what a band of people on forums say without providing any real reasoning to support your claims. A common misapprehension on your behalf even if you meant well. Its unsound as you have made assumptions on the nature of battery types, quality, use case etc.
Your incorrect assertions dont jive with reality, almost all off griders in the Lead Acid world size their battery for DoD, NOT for total throughput. The reasons should be very obvious, like weather, short sun hours, and sulphation.
* Actually cycles are indeed a measure of the lifetime energy and this is strongly supported by facts like off griders getting 10years plus out of their LA sizing by DoD, by the science (chemistry) that governs the inner workings of the batteries, and the correct common sense logic that deals with sulphation and other factors like how its a pain in the rear to replace batteries too early for various reasons. Simply put, many folk have top priority to get maximum years out of their battery and that is only done with LA by keeping to a shallow DoD. those are true statements based on correct science and facts.
You have made the fatal error of ignoring realworld sulphation due to poor sunhours, drive times, long absorption times required etc, which at deep discharges will accelerate the demise of a LA rapidly. Again this is common accepted science and why most in the LA world size to shallow DoD. Sulphation is a compounding problem, every imperfect cycle and deeper cycle at that the lead sulphate hardens even more. There are different brands and quality of brands so you just cant give a general rule. The cycle life the manufactures provide is in a lab with perfect charging conditions. If you can routinely get back to a true 100% float stage then yes 80% DoD will be probably fine for most, at least based on my testing.
So the general rule has always been: the correct DoD depends on what you are doing and what batteries you have exactly. If your doing a few weeks at a time and top up every month or so 80%DoD is probably fine, if your on the road full time and want max stability and years you would be very foolish to size below 30%DoD. Its not a myth, that is your misunderstanding, remember, as they say behind every belief there is a kernel of fact.
* No this does not apply to Lithium batteries because you have no proof, no evidence, probably not even a dataset to support such a black and white claim. It hasn't been demonstrated in anyway that this is true with LiFePO4, no one has quantified the cycle life and DoD, this has been shown with other lithium chemistries that have shorter cycle life, but not with LiFePO4. You dont know, I dont know, no one does. But again, for some people like me, we want maximum years and stability/minimal work, so sizing to a shallow DoD is the way to go. Further more, another mistake you made is not recognizing that with lithium-ion the total throughput isn't linear or even the same amongst all li-ion, why do you think many Ev's cycle between 20-80? because its been know for a long time with some lithium that you actually get the max throughput when cycling between say 40-60 or 30-70 etc. But with so many subtle chemistries, different designs and formulations making a blanket statement is just wrong.
Peter_n_Margaret said
08:18 AM Sep 2, 2024
As I stated, the data used in my post is from Fullriver.
If you have a credible alternative source, please post it.
Cheers,
Peter
Hello everyone,
My son who lives in Canberra bought a 2nd hand (2years old) Jayco Eagle recently. He found last weekend that while the sub was out, his battery was discharging. I suggested he may have a blown fuse, a dodgy joint somewhere.
Today he did some testing including wriggling some wires & found that he was getting (in full sun):a charge of 4A. I would have thought it should be a bit higher but knowing Canberra to be a little cool at this time of the year & the panel is mounted flat on the roof, should he be expecting to see around double that charge?
Are there any other members who live in Canberra & who may have the optional solar/lithium power set up on their Jayco Caravan. It seems to be a standard set up.
The solar panel is 180w, the BMPRO is J35, model B-L. The previous owners were unable to tell him much about the unit, they hadn't used it much & were just interested in recouping some of their lost cash.
The battery is a 100Ahr lithium - I'm hoping the previous owners didn't just pack it away without maintaining some sort of a charge. Do lithium batteries suffer similarly to AGMs if not properly maintained?
We had a similar experience when we bought our Eagle - the owners just charged it when they were going to use it - with the Jayco 5A charger!! The battery was stuffed, terminal voltage was 3.5v!!
Lithium battery is not normally stuffed at 3.5V, it's below the charging threshold of 10.5V for most chargers and BMS.
Check youtube how to charge a depleted Lithium battery.
AGM batteries should not be depleted below 50% in normal use to retain efficiency. Lithium can be depleted over many, many cycles and still remain efficient.
That is an urban myth. Completely false.
Cheers,
Peter
Urban myth?
Q&A: What is a battery cycle and how do they affect battery life? (youtube.com)
Yes, urban myth.
Cycles is not a measure of the lifetime energy delivered from a battery because the cycles are not the same size.
I have not watched your video, I consult the manufacturers who have proper data. (See Fullriver data attached)
See the lifetime cycles for various depths of discharge and then convert those to Ahr actual energy delivered.
Just in case you don't want to do it yourself, it looks something like this.... (based on a 100Ah battery)....
30% DOD = 1420 cycles x 30Ah per cycle = 42,600 Ah total life.
50% DOD = 650 cycles x 50Ah per cycle = 32,500 Ah total life.
70% DOD = 450 cycles x 70Ah per cycle = 31,500 Ah total life.
100% DOD = 280 cycles x 100Ah per cycle = 28,000 Ah total life. (about 7% less than 50%).
(ps - 100% DOD is defined as 10.5V)
And of course, if you restrict the DOD, you need to carry more batteries (which weigh more and cost more, but need replacing less frequently).
And if you restrict your DOD to zero, they last forever. :) But they don't of course, because there is a time based deterioration as well. So there is a
good argument for working your batteries hard and replacing them more often. And the bloke (including me) who says "My batteries lasted for 9
years" means absolutely nothing.
Cheers,
Peter
EDIT: Of course, EXACTLY the same applies to Lithium batteries, except the numbers are bigger.
-- Edited by Peter_n_Margaret on Sunday 4th of August 2024 01:22:57 PM
-- Edited by Peter_n_Margaret on Sunday 4th of August 2024 01:25:34 PM
Don't tell me as it is not my opinion, watch the videos and tell those in the business giving the advice.
The lower and the often the battery DOD the quicker the battery will deteriorate. And that is not my "opinion".
-- Edited by Dick0 on Sunday 4th of August 2024 06:02:17 PM
Cheers,
Peter
Don't tell me as it is not my opinion, watch the videos and tell those in the business giving the advice.
The lower and the often the battery DOD the quicker the battery will deteriorate. And that is not my "opinion".
Maintenance tips for a "Maintenance-Free" AGM Battery for off-grid solar power systems. (youtube.com)
How to charge and maintain deep cycle AGM batteries with Craig from KickAss Products (youtube.com)
How to Maintain and Use AGM Deep Cycle Batteries (youtube.com)
Watch the videos.
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
If it is not your opinion, don't spread this misleading advice around.
The total energy that a battery can deliver in its whole life is not seriously affected by the depth of discharge that it is used at.
You can not measure a battery's ability to supply energy in cycles. Measure it in Watt hours (or Amp hours).
That is a fact backed up by manufacturer's data. Do you have any manufacturer's data (from any reputable manufacturer) that is different to that?
Cheers,
Peter
180 watts of panels horizontal position in Canberra today the sun's height at:
9am 21° = 64 watts
10am 29° = 87 watts
11am 35° = 103 watts
12.09pm 38° = 110 watts
Assuming perfect weather & perfect efficiency.
In your smartphone type the following (photo attached):
If you have inclement weather use the battery's full capacity. That is what it is there for. In you do this once a month over five years it's only 60 cycles. It will barely make any difference.
Watch the videos.
The LiFePO4 battery may very well not be stuffed. It may very well have been drained down so that the BMS inside the battery activates the low voltage disconnect. When this happens you will still get the low voltage that you are seeing though the terminals but the actual cell voltage may well be higher.
If the battery will not charge using the solar controller or a battery charger then you need to do what we call a jump start.
Follow this link to get the battery out of safe mode.
https://itechworld.com.au/blogs/learn/lithium-battery-safe-mode
Once that has been done we can look then look to see if there are any other problems.
Here is your manual
https://teambmpro.com/wp-content/uploads/035664_M-J35CN2_v8.pdf
My apologies as you will need to copy and paste the links. for some reason it has given up on me again.
To add to the above your BMPro should still charge the battery even if the BMS has shut down.
Heavily Discharged LiFePO4 Batteries (J35B-L / J35D)
The J35B-L and J35D can recover and charge a heavily discharged LiFePO4
battery. The internal Battery Management System (BMS) of a LiFePO4 battery
will turn off if it detects that the battery is heavily discharged. The J35B-L or
J35D will provide the voltage to restart the LiFePO4 batterys BMS and then
commence charging of the LiFePO4 battery
Tim
-- Edited by TimTim on Sunday 4th of August 2024 10:32:02 PM
-- Edited by TimTim on Sunday 4th of August 2024 10:57:24 PM
Do people actually believe everything they see on U Tube???
Nope.
Our 4 cell 300Ah LiFePO4 battery has survived 10 years of fulltime travel and counting.
I can tell you plus or minus 1% the battery energy delivered in Wh or Ah.
I could not tell you plus or minus 80% the number of cycles it has been through.
Cycle counting in a typical RV setup is an impossible task and all but irrelevant anyway. It would require some consistency in daily energy use. Non existent here.
OR
Watch this video.
Youtube non believers do not bother.
3 Ways To JUMP Start And WAKE A DEAD Lithium LiFePO4 Battery FAST! (youtube.com)
lol Dicko. Hope you are keeping well.
Plenty of good stuff on youtube, just have to sort out the wheat from the chaff
. The same in life in general.
Tim
David my son, who knows little about technical items is slowly learning. A few years ago I gave him a multimeter for Christmas & wondered at the time whether I gave him something he would never use! It is now getting a work out.
After the first attempt at getting the battery to charge, he put it on to mains power & fully charged the battery, according to the app.
Last Saturday he had another go at it & borrowed a neighbour's solar blanket. He discovered that the flash controller wouldn't let anything flow into the battery until a certain discharge voltage was reached. It then woke up & proceeded to send 4.3A into the battery, Adding the blanket into the external charging plug on the camper have him another 4A. A while later the batter reached full charge (on the app)
So my question comes & I have more to read up on this system it seems, is why if the battery needs just over 8A to fully charge it again - why won't the 200w panel supply it (bearing in mind losses due to having a flat panel vs one raised at the correct angle)?
David is planning a trip on long service leave to WA soon, hopefully free camping where possible. It will try out both his wife & teenaged daughter who both are not campers!
Hi Warren,
Well you have shown us that your battery charges and there appears to be an issue with either your BMPro for solar charging or your solar panel, or maybe the connections between the two.
Have your son put the multi-meter on the + and - solar panel input terminals of the BMPro whilst the solar panel is in full sun and it should read around the 23V mark. I have sent you the link for the manual previously. But to be exact there will be a label on the back of the panel which tells you the Voc. The voltage should be close to that. If not then it will be time to test the connections in the cables if there are any or the connector box on the back of the solar panel. Also look for a fuse in the cable although you don't need one. You did say in your first post that wriggling the wires you did get current so it would seemlike a faulty connection somwhere.
https://www.youtube.com/shorts/oV8SnZJextc
https://www.youtube.com/watch?v=UnZ0-ZLm1KE
Good luck
Tim
-- Edited by TimTim on Monday 12th of August 2024 10:54:10 PM
I cannot recall when I used Trigonometry calculations for working out angles, etc - perhaps it was around 40 years ago when several of us did a night school maths course to pass a qualification to become a Tech Officer within the then Telecom Australia (we all failed but the special course enabled us to know what the examiners were asking)!
And Tim, Getting back to your assistance, thank you also. My comment on the "Flash" controller meant the BMPro. The solar blanket did not have a controller fitted to it - it was fed into the "Unregulated Input" on the trailer - I assume it goes into one of the Auxillary inputs of the BMPro. We have had or planned trip to Canberra to house sit the animals while they are away & will if all goes well arrive before "Grandparents' Day" in late September. That will give me an opportunity to chase up what goes where & to do some testing myself, including utilising a dummy load on the battery. And it "might" give me an opportunity to find out something about the solar panel - which is mounted 15mm clear of the roof!!
I've tried to find out what panels Jayco use - it's not easy. The American ones use a panel made or sourced by "Go Power", here in Australia??? I'll check with a chap who works for Jayco Townsville to see if he can be of assistance. I had my son short out the panel with his meter on the 10A range & I recall him saying it was about 4A. That leads me to two issues - either there's not enough sun or there's a dudd joint somewhere from the panel to the BMPro.
(Our house had an issue when I had one of "Rudd's Dudds" install our solar system in 2011 - they used dissimilar connectors, water got in & caused arcing. We had Decramastic tiles on the roof at the time. If it hadn't been for a neighbour out mowing his lawn, smelling smoke & calling the fire brigade, we would have lost the house!)
Regarding the type and spec of the Jayco panel, I suggest that someone gets up, lifts the panel and takes a photo of the name plate and its specs.
I reckon Jayco do not always use the same make and specs for their vans. My van came with a notional 150 watt panel. Someone I know who had a similar and same year built Jayco van is fitted with a panel that is specified at 160 watts, though it is the same physical dimensions.
I added another 175watt panel to my roof. The same physical dimensions as the original panel, though a different brand.
I connected the panels in parallel circuit and tried to select the new panel with a similar voltage output for better efficiency of combined panel output, of course taking cost and perceived quality recommendations into account.
If one presses & holds for a second on your mobile phono, the link text which will then highlight in its entirety & the ask to open etc.
You do not need the text to be linked as such.
Warren. As I see it the max current under ideal conditions from a 180 W panel would be less than 13 amps. In Canberra at this time of year I think you would be lucky to see 4 amp.
Alan
-- Edited by Brenda and Alan on Thursday 15th of August 2024 09:43:06 AM
I'm going to add a Jaycar (or Temu - are these any good?) digital voltmeter controlled by a switch to the adjacent panel on the 'power cubicle' so the battery voltage can be seen easily.
I went to our local Jayco dealer on Thursday & found the current panels that are being installed (or since 2022) are Sphere 200w panels. According to RV Parts Express, these are quite reasonable panels & now are the same physical size as the previous 180w panels. I don't want to add any more to his roof as the cables that raise the roof have a nasty habit of breaking.
We are driving down to Canberra in mid September, so I'm looking at being able to do some better testing myself. This trying to do it remotely is a drama! Some say we should live closer - all very well but I can't cope with the cold nor the house prices down there!
Alan, thanks too for your assumption on Canberra's weather conditions for running solar. I know the sun there is far more scarce there than it is here in NQ!
Warren,
The voltage is not an accurate way of determining the state of charge of a LiFePO4 battery. This is because the the charge and discharge curve are very flat until they come to what we call the knee. If you look at the attached chart, which will only be an approximate, you can see that between 13.0V and 13.3V there is a 60% difference in the state of charge.
To get a more realistic SOC you will need a shunt which you can either get with a display or Bluetooth.
https://au.renogy.com/500a-battery-monitor/?
https://itechworld.com.au/products/itechbm500-500-amp-battery-monitor-with-shunt-high-and-low-voltage-programmable-compatible-with-12v-lithium-sealed-gel-flooded-batteries?
https://www.everybattery.com.au/product/shu065150050-smartshunt-500a-50mv-ip65/?
Tim
-- Edited by TimTim on Saturday 17th of August 2024 11:09:15 PM
This post is very dogmatic and unsound, all you have done is repeat what a band of people on forums say without providing any real reasoning to support your claims. A common misapprehension on your behalf even if you meant well. Its unsound as you have made assumptions on the nature of battery types, quality, use case etc.
Your incorrect assertions dont jive with reality, almost all off griders in the Lead Acid world size their battery for DoD, NOT for total throughput. The reasons should be very obvious, like weather, short sun hours, and sulphation.
* Actually cycles are indeed a measure of the lifetime energy and this is strongly supported by facts like off griders getting 10years plus out of their LA sizing by DoD, by the science (chemistry) that governs the inner workings of the batteries, and the correct common sense logic that deals with sulphation and other factors like how its a pain in the rear to replace batteries too early for various reasons. Simply put, many folk have top priority to get maximum years out of their battery and that is only done with LA by keeping to a shallow DoD. those are true statements based on correct science and facts.
You have made the fatal error of ignoring realworld sulphation due to poor sunhours, drive times, long absorption times required etc, which at deep discharges will accelerate the demise of a LA rapidly. Again this is common accepted science and why most in the LA world size to shallow DoD. Sulphation is a compounding problem, every imperfect cycle and deeper cycle at that the lead sulphate hardens even more. There are different brands and quality of brands so you just cant give a general rule. The cycle life the manufactures provide is in a lab with perfect charging conditions. If you can routinely get back to a true 100% float stage then yes 80% DoD will be probably fine for most, at least based on my testing.
So the general rule has always been: the correct DoD depends on what you are doing and what batteries you have exactly. If your doing a few weeks at a time and top up every month or so 80%DoD is probably fine, if your on the road full time and want max stability and years you would be very foolish to size below 30%DoD. Its not a myth, that is your misunderstanding, remember, as they say behind every belief there is a kernel of fact.
* No this does not apply to Lithium batteries because you have no proof, no evidence, probably not even a dataset to support such a black and white claim.
It hasn't been demonstrated in anyway that this is true with LiFePO4, no one has quantified the cycle life and DoD, this has been shown with other lithium chemistries that have shorter cycle life, but not with LiFePO4. You dont know, I dont know, no one does. But again, for some people like me, we want maximum years and stability/minimal work, so sizing to a shallow DoD is the way to go. Further more, another mistake you made is not recognizing that with lithium-ion the total throughput isn't linear or even the same amongst all li-ion, why do you think many Ev's cycle between 20-80? because its been know for a long time with some lithium that you actually get the max throughput when cycling between say 40-60 or 30-70 etc. But with so many subtle chemistries, different designs and formulations making a blanket statement is just wrong.
If you have a credible alternative source, please post it.
Cheers,
Peter