LA Batteries Failing on Victron System

[RedSky]

Hoping someone can help with my Victron MPPT+Shunt+Protect and Yuasa lead acid leisure battery setup. The batteries started failing at under one year old, and now at one year they are pretty much shot. Apart from two short breaks the van has been UK touring for six months. The stated cycle life on these Yuasa batts is 200 but for shallow discharge I expect far more. They should have lasted longer than this.

System components:
Victron BlueSolar MPPT 100/30
Victron BMV-700 battery monitor & shunt
Victron Battery Protect
Victron Smart dongle x 2
Sunshine Solar 100W x 3 panels series wired
Merlin VSR 140A (13.3V connect/12.8V disconnect)
Yuasa L36-EFB 100Ah leisure x 2

The SOC on my BMV-700 very rarely goes below the 80% region. This should take the life of these batteries into several years. I know of van lifers on YouTube with lead acid batteries several years old. The late Allan Evans at A & N Caravan Services rated the Yuasa L36-EFB higher than many AGM's. But now, in the morning after an overnight park up, the Victron app typically shows above 80% SOC/30Ah used and about 11.5 volts. Not enough to run the fridge - when the compressor starts the Victron app shows the amps building up, volts dropping to 11 and then the fridge shuts off. So what is going wrong? I need to find out before installing new batteries.

I have the usual LED lighting, water pump, phone and laptop charging. Significant consumers are the compressor fridge and a CPAP unit. After an overnight stop and on starting the van the 180amp alternator will kick out 60amps, reducing and then gradually declining during driving until the leisure bank is charged. Without summer solar, if we're not driving early in the day the engine has to be run for half an hour to get the voltage up and keep the fridge going. This is daft with a 200Ah battery bank and 50% floor on the Victron Battery Protect. And with just 30Ah deficit showing on the app, the voltage should be higher.

Either the Yuasa L36-EFB batteries are not fit for purpose, or the Victron units are not working correctly, or they have been set up incorrectly. The MPPT 100/30 is on the default setting position 2. The BMV-700 battery settings are either default or set by my installer, a member of the approved workshop scheme but not a Victron agent. I've moved away from the installer location so cannot ask them, and in any case don't think they were Victron supremos.

One thing I've noticed is that the SOC percentage doesn't exactly match up with the consumed amp hours, e.g. the phone app shows 84% SOC and consumed Ah of -34.9 when my maths says it should be -32Ah. A small difference maybe, but if the Victron system is not accurate there could be issues affecting the batteries.

I've switched all my consumers in and out to see if any were not registering on the shunt. What else could be causing this problem?

 

[Fletton]

two things come to mind...
Electroblok set to Lead Acid...?
MPPT got correct charging profile?

 

[RedSky]

Thanks for the reply. No Electroblok, my habitation standard electrics run through the PMS3H control box that came with my van. The PMS has a simple single stage charger built in. However we go wilding so I'm never on EHU when touring. During the first six months life of these batteries when the van was up the drive during Covid lockdown they had a combination of winter solar (almost nothing) and a weekly charge through the charger mentioned above. I had an energy monitor on the house socket that was plugged to the EHU and could see the energy going down during the day, so think they were floating by the end of the charge.

The Victron MPPT 100/30 charger is set to position 2 which is headed Gel Victron deep discharge. I know my batts are not gel but on this setting the charger outputs 14.40V absorption and 13.80V float. This is the default setting that the charger comes with, and it matches the voltage spec set by Yuasa for their L36-EFB. Victron in the manual recommend staying with the default unless the user knows what they are doing, and although I'm handy this subject leaves me puzzled. I'd be very happy for someone to lead me forward.

I've noticed that the BMV-700 monitor does not give readings under some of the headings. It shows deepest discharge, last discharge and cumulative Ah drawn but no reading for average discharge. It shows time since last full charge, synchronisations, but no reading for total charge cycles or number of full discharges. It shows max battery voltage but not min battery voltage. Is that normal? Anyone got one of these monitors? Might my monitor not be working properly?

The monitor indicates that I was sitting at under 11 volts today with only 30 Ah used from a 200 Ah battery bank. Had to put the engine on since we're going nowhere today and the fridge wasn't working. Engine has been running nearly an hour as I write this. Monitor is showing 14.12V, 9.33A (incoming from alternator) and consumed Ah -7.9Ah. A few minutes later the voltage is 14.13, 8.72A and -7.5Ah. SOC is 98%. I'll turn engine off now. VSR clicked off a few seconds later. Voltage goes to 12.5V, though fridge is currently pulling 6amps. By early morning the voltage will be 11.5V. I shall probably go lithium once this is sorted but cannot risk trashing that sort of money until I understand more. Hoping there are people out there that can help.

 

[PhilandMena]

It is only 24 KG in weight and looking at the data sheet it does not state how many cycles and to what DOD. Although the NCC does state up to 230 cycles@50% DOD.
I too would expect these to last longer than they have if only discharged by 20 %. Something is not right here. That weight is poor though IMO

 

[Bobby-gg]

It is only 24 KG in weight and looking at the data sheet it does not state how many cycles and to what DOD. Although the NCC does state up to 230 cycles@50% DOD.
I too would expect these to last longer than they have if only discharged by 20 %. Something is not right here. That weight is poor though IMO

Why are you thinking that the battery weight is poor?

It's exactly the same weight as another highly recommended leisure battery, the LFD90 Varta, which is in the same sized casing

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[pappajohn]

I know my batts are not gel but on this setting the charger outputs 14.40V absorption and 13.80V float.

Voltage too high.
You possibly cooked your batteries.
Lead acid ....14v absorption
13.6 float.
Gel & AGM are near enough the same values as each other

 

[autorouter]

One possibility is that the BMV shunt is not accounting for some currents because it is being bypassed. Can you confirm that on the BMV shunt, there is NOTHING except the battery negative wires connected to the 'battery' terminal of the shunt. Do you have a temperature sensor on the battery?

As pappajohn says, maybe you cooked your batteries. Normally for flooded lead-acid, the absorption phase lasts until the amps drops below a threshold value. On the Gel setting,the absorption phase continues for a timed period, often several hours, to allow 'recombination' to take place. This is not required for flooded lead-acid, and could be the problem.

 

[JockandRita]

The Victron MPPT 100/30 charger is set to position 2 which is headed Gel Victron deep discharge.

Voltage too high.
You possibly cooked your batteries.
Lead acid ....14v absorption
13.6 float.
Gel & AGM are near enough the same values as each other

As @pappajohn says, maybe you cooked your batteries. Normally for flooded lead-acid, the absorption phase lasts until the amps drops below a threshold value. On the Gel setting,the absorption phase continues for a timed period, often several hours, to allow 'recombination' to take place. This is not required for flooded lead-acid, and could be the problem.

RedSky. We had the same problem on our first MH years ago, ie, the leisure batteries were Varta FLA, always needed topping up, (being cooked/fried), and never held their charge. On investigation, I discovered that the setting on the Schaudt EBL was set for Gel, rather than for Lead Acid. Apparently the factory setting and installation was for Gels, which must have been replaced with FLAs before we got it.

Once I sorted that out, things were fine with replacement batteries.

We are currently using 4 x Varta LFBs, on Lead Acid settings from the CBE charger, the Sterling B2B charger, and the 2 x MPPT solar controllers ,with no issues at all......................albeit we are not running a compressor fridge.

Good luck getting it sorted.

Cheers,

Jock.

 

[Raul]

You running in deficit, by trusting the monitor that has drifted long time ago. If voltage is 11,5v and monitor says only 30ah consumed, this alone should tell you something is not right.
Charge the batteries fully with ehu, then re set the monitor to 100% if doesn’t do it itself. I suspect it will reset, when your batteries are nowhere near full. Get them proper charged and start from a known reference point. Voltages are good, not high at all, in fact you can increase temperature compensating charging to 24mv instead the 16mv default.

I just looked up the spec on your battery, yes agree very light for a 100ah, and has mca and cca ratings, that’s a dead giveaway this is NOT a deep cycle, more off a starter with very little deep cycling capability. I would not go below 20%dod on this. Any deeper, expect 150-200 cycles top.
A true deep cycle 100ah weighs in the region of 27-33kg, depending on cycle and dod rating. And no CCA rating.

 

[Lenny HB]

Your single stage mains charger probably only charges at 13.8v if this is the case the batteries will never get a full charge and it will shorten their life considerably.

I wouldn't worry too much about the percentage reading on the BMV 700 takes a fair bit of work with the settings to get it right, took me a couple of weeks to get mine set up.

Basicly your batteries are giving up after drawing 30 amps out of them so one or both of them are shot.

One thing you really don't want to do is run the engine from cold on tickover, it can do a lot of damage as the engine never gets up to operating temperature. If you really need to do it take for a drive to get it fully up to temperature then you can leave it on tickover.

When you have changed the batteries I suggest you buy a decent multi stage charger.

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[PhilandMena]

Why are you thinking that the battery weight is poor?

It's exactly the same weight as another highly recommended leisure battery, the LFD90 Varta, which is in the same sized casing

​

Sorry for the delay in responding to your post. The key to L/A battery life is the amount of lead in the battery. The more lead the more life.
IMO 24 KG is at the lower end of the scale for a good L/A leisure battery. The Exide ET650 as an example and also a L/A battery is 26.5 KG.
You referred to the Varta LFD90 yet when this was first produced it was stated on Varta's own website this battery was for low to moderate use. I've checked again but they no longer list this battery as they have newer types on there website, so you only have my word on that. Regardless of all that and with the amount of Solar you have something is clearly amiss and you batteries should be lasting a lot , lot longer than they have. I too read about AandNcaravans review of these batteries and I think a lot of our members purchased these batteries on his recommendation and there have been little to no reports of premature failure before your post to the best of my knowledge. Hope you get it sorted. Electrical problems can be a nightmare.

 

[RedSky]

Thank you everyone for your replies. BTW, how do I 'like' a posting? Can't see anything in the string. Or is it that I'm on probation as a new member?

Back to the subject: Yuasa recommend 14.4V absorption and 13.5-13.8V float for these batts. So my MPPT setting is OK in terms of voltage. But if the gel charge profile is not suitable for LA, as suggested above, that would not be good. However none of the other eight presets in the MPPT settings match the voltage required. There is an expert mode option but I can't claim to be that, and it's strange there isn't a preset profile for a LA-EFB battery type. These are not uncommon, and have a different spec to standard LA. Would the gel profile that I'm on kill my batteries so quickly?

Yup, the single stage charger in my PMS3H hab power system outputs 13.8V. It can go to 18amps but the actual amps was fractional when floating the batts once a week in their first six months of life during Covid lockdown. The van was sitting on the drive doing nothing. A tiny bit of winter solar going in from 3 x 100 watt panels. A tiny bit of drain from Victron dongles and other standby. And a weekly top up from the PMS3H charger which I think was pretty much a float, and at 13.8V was what Yuasa specify. If I'm wrong in my thinking here, would the batteries be affected so badly to get me to current status?

I'm sure that my shunt is measuring everything since all consumers have been individually switched on and off, and the effect on the BMV-700 monitor watched carefully on my phone app. The monitor shows about 30Ah used each day. On the occasion we don't move for two days it shows about 60 Ah used. In either case, on starting the engine and driving off the alternator charges the batts back to full - the monitor at the end of the day showing 0Ah under the Consumed Ah heading. Ah but, you might say, the monitor is clearly out of balance in light of my problems. Yes, it is not showing correct SOC. But the Ah used that is recorded on the monitor is correct I think, because it fits with the consumers I'm using in the van. I'd expect the fridge, CPAP and other stuff to be using 30 Ah.

Re alternator charging, correct me if wrong but I don't believe that the monitor/shunt or MPPT would affect the alternator output, so if the Victron SOC calculation is incorrect the alternator will still be independent and will output what is required to fully charge the battery. After a day of driving the alternator, via my VSR, will have fully charged the leisure batteries. The VSR is rated 140amp so no bottlenecks there. The monitor shows high incoming current on starting the engine. It depends on the deficit but typically about 50-60amps, declining to a couple of amps at the end of the day. However I notice that the monitor shows voltage at about 14.2V at the end of the day with the alternator running. So, not the 14.4V absorption or indeed the 13.5-13.8V float that Yuasa specify for my L36-EFB. And earlier in the day when amps are high the voltage is lower. The alternator has been my primary charging source, so is this the main problem, not providing the correct charge profile?

If I've got anything wrong in the above thinking, reported facts etc, (other than Yuasa's clear spec on battery voltages) please let me know.

I remember Charlie Sterling telling me I didn't need a B2B for LA batteries but I'm thinking now that maybe he wasn't familiar with the higher volts required by the EFB version. Jock in his response above has listed a B2B in his lead acid setup. I assume this has preset settings but can be altered to suit any battery? So is a B2B the missing link in my setup? Is that the reason I've toasted my batteries in less than a year?

 

[Raul]

One problem for sure in the alternator charge rate, whacking them with 50-60A charge rate is not healthy. They will take it, to the expense of electrolyte loss, corrosion, active material shedding, and short life.
A lead should not exceed C/5 max charge rate, that’s 20A charge for every 100ah capacity. The Goldilocks is C/10, but anything from C/12 to C/8 is considered healthy rate. The same goes for discharge to, it’s the same chemical process, just in reverse. The ones you can abuse on charge are pure lead, but still short lived. Another think, the ehu only provides a float charge, nothing wrong as long as you got the luxury of charging time, even 3days for half discharged. Remember, the lead is around 75% efficient at best, and for every 10ah consumed, you need to put 15ah back, that’s round trip efficiency, IF they are healthy.
Now your bmv monitor comes with default settings that are universal, and most batteries will not be far of. It does a pretty good estimate, but, as your batteries age, and condition change, so this settings need changing. Otherwise the calcs. and the values will be off, not in line with the tired batteries condition. Even setting your capacity it alters the estimation. If they lost capacity, and that value has not been changed in the bmv, then it will calculate wrong. The bmv only does is calcs. based on user input values.

 

[AgeingAndrew]

The Yuasa web page for the L36-EFB states that the intended purpose of the L36-EFB is, and I quote, 'for use with electrical hook-up with minimal off grid habitation usage e.g. Lights, TV plus motor mover'. I can't help thinking that you are trying to get too much from EFB batteries, especially with the compressor fridge. Maybe look at replacing the EFBs with something more appropriate to the application. As you are so dependent on alternator charging then fit a suitable B2B or regularly use EHU with a decent mains charger to make sure your batteries are treated well.

 

[autorouter]

As Raul says, if your your SOC says 80% and the voltage is about 11V, something is seriously wrong. And I'd agree that the first thing is to charge the batteries to a known state at 100%. It takes several hours to charge a battery at 11V up to full charge, you'd be advised to charge them for 24 hours minimum with a smart charger.

Then try a known load on the batteries, and see how they get on. Ignore the SOC reading, measure the amps draw and calculate the amp-hours used - for example 5 amps for 4 hours is 20 amp-hours. Then turn off the loads, and measure the voltage.

If for example one of the batteries has a failed cell, the voltage might drop fairly quickly to around 11V. If it does, then test each battery separately, it might only be one that has the failed cell.

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[PhilandMena]

I have done the test recommended by autorouter not too long ago and this is how it went.
original post from autorouter, as follows;
You're going to be sorry you said that Here's how to do it.

1. Fully charge the battery, leave it to settle for a couple of hours.
2. Attach a load that draws an amps value of Capacity/20. (for example for a 100Ah battery, 100/20 = 5A.
3. Run the load for 5 hours. The amp-hours taken from the battery is Amps x 5 hours. (for the same example, 5 x 5 = 25Ah. For a brand new battery this would be 25% of the capacity, so it should be down to the 75% level.
4. Let the battery settle for a couple of hours
5. Measure the voltage.
6. Use this voltage, referring to the battery charge/voltage scale (In Lenny HB's post #32) to estimate what percentage charge is left in the battery. For this example, let's suppose it is 12.28V. If it's a Sealed Lead-acid type, that represents a level of 60%. Since you drew 25% of the label capacity, you would expect the voltage to be at the 75% level on the charge/voltage scale. However because the battery has aged, it is now at the lower level of 60%.

7. If the battery is actually at 60% when you expect it to be 75%, its capacity when full is
(60 / 75) x 100 = 80% of the original capacity.

So the battery capacity has reduced due to aging, and is now only 80% of its original capacity.

Start of test :
OK! I have now started my test. At 09.00 this morning both batteries were found to be 12.96 V. They were disconnected at 14.00 hrs yesterday and both at 13.66 V.
I have put a 4.6 Amp load on to one of the batteries at 09.00 and it dropped immediately to 12.33 V (which is meaningless information !) I'll leave the load on for 5 hours then remove load allow to settle and calculate remaining capacity. I'm only going to do this one on one of thee batteries as they have both been linked as a pair from new and the readings up to the point where a load has been applied have been identical. Watch this space.

So First update. Test is now completed. I measured the voltage with the load of 4.6 Amps still applied and after 5 hours the voltage reading dropped from 12.33 to 12.25 a drop of 0.08 of an Amp what does this mean. I don't have an effing clue
I will measure battery in an hour to see where its at. A picture of the battery at the the end of the test.

Test is more or less finished but my maths do not make sense.
After resting the battery for one hour it measured 12.56 Volts. I have taken 23 Amps out of the battery leaving 77 Amps (100 AH Battery)
So! 90/77 x 100 = 116 ?
But if I do this 77/90 x 100 = 85.5 This would indicate I have used 14.5 % of my total battery capacity which I think makes sense !
Very happy with that, if it is correct ? I will measure again after two hours resting.

FLT, GSM, CBBC & Bar, VD & Scar.

 

[autorouter]

After resting the battery for one hour it measured 12.56 Volts. I have taken 23 Amps out of the battery

The battery started off at 12.96V (100%). It dropped to 12.56V. You need a chart to tell you what percentage that represents. Then you can see how much (percentage) it has dropped by. Let's say it's X%.

What is that percentage loss in amp-hours? That X% loss represents a loss of X% of 100Ah, That's X/100 x 100Ah. Because it's a 100Ah battery the loss is actually X Ah, for other battery sizes, use a calculator.

In other words, you would have to take X Ah out of a brand new battery for it to fall from 12.96V to 12.56V

You actually only took out 23Ah, the actual capacity of the degraded battery is 23/X x 100 percent of the batery when it was new.

 

[JockandRita]

Jock in his response above has listed a B2B in his lead acid setup. I assume this has preset settings but can be altered to suit any battery? So is a B2B the missing link in my setup?

Yes, the B2B be it Sterling, Victron, or otherwise, does have preset charging settings. The Sterling B2B even has "custom" settings to actually choose the charging regime of your choice.
As we prefer to be off grid and moving about every couple of days (especially abroad from Aire to Aire/Stellplatz to Stellplatz), the B2B is essential for us, in addition to solar power.

Cheers,

Jock.

 

[chrish]

Just a thought,
On the BMV-700 there is a setting 70. Start synchronised, if this is On when the BMV is powered on it will assume 100% state of charge when it could be considerably different.
This could explain why the SOC is showing 80% at 11v, this sort of thing happens when you have disconnected the batteries and reconnected them when they are not fully charged with setting 70 On.

 

[PhilandMena]

The battery started off at 12.96V (100%). It dropped to 12.56V. You need a chart to tell you what percentage that represents. Then you can see how much (percentage) it has dropped by. Let's say it's X%.

What is that percentage loss in amp-hours? That X% loss represents a loss of X% of 100Ah, That's X/100 x 100Ah. Because it's a 100Ah battery the loss is actually X Ah, for other battery sizes, use a calculator.

In other words, you would have to take X Ah out of a brand new battery for it to fall from 12.96V to 12.56V

You actually only took out 23Ah, the actual capacity of the degraded battery is 23/X x 100 percent of the batery when it was new.

The chart that you refer to above.

My voltage loss was less than 10% So I calculated 77 (Remaining Amps) divided by 90 (Volts) Multiplied by total Battery Amp Hours) 100 = 85.555 Which i calculate as remaining capacity. (12 56 volts is nearer 100% fully charged than 90 % so my remaining capacity may be even higher ? According to Alpha batteries when a batter has used 20 % of its capacity it is regarded as reaching its end of life. What a load of Boll***s. More marketing crap IMO

Remaining

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[Stephen28]

Hoping someone can help with my Victron MPPT+Shunt+Protect and Yuasa lead acid leisure battery setup. The batteries started failing at under one year old, and now at one year they are pretty much shot. Apart from two short breaks the van has been UK touring for six months. The stated cycle life on these Yuasa batts is 200 but for shallow discharge I expect far more. They should have lasted longer than this.

System components:
Victron BlueSolar MPPT 100/30
Victron BMV-700 battery monitor & shunt
Victron Battery Protect
Victron Smart dongle x 2
Sunshine Solar 100W x 3 panels series wired
Merlin VSR 140A (13.3V connect/12.8V disconnect)
Yuasa L36-EFB 100Ah leisure x 2

The SOC on my BMV-700 very rarely goes below the 80% region. This should take the life of these batteries into several years. I know of van lifers on YouTube with lead acid batteries several years old. The late Allan Evans at A & N Caravan Services rated the Yuasa L36-EFB higher than many AGM's. But now, in the morning after an overnight park up, the Victron app typically shows above 80% SOC/30Ah used and about 11.5 volts. Not enough to run the fridge - when the compressor starts the Victron app shows the amps building up, volts dropping to 11 and then the fridge shuts off. So what is going wrong? I need to find out before installing new batteries.

I have the usual LED lighting, water pump, phone and laptop charging. Significant consumers are the compressor fridge and a CPAP unit. After an overnight stop and on starting the van the 180amp alternator will kick out 60amps, reducing and then gradually declining during driving until the leisure bank is charged. Without summer solar, if we're not driving early in the day the engine has to be run for half an hour to get the voltage up and keep the fridge going. This is daft with a 200Ah battery bank and 50% floor on the Victron Battery Protect. And with just 30Ah deficit showing on the app, the voltage should be higher.

Either the Yuasa L36-EFB batteries are not fit for purpose, or the Victron units are not working correctly, or they have been set up incorrectly. The MPPT 100/30 is on the default setting position 2. The BMV-700 battery settings are either default or set by my installer, a member of the approved workshop scheme but not a Victron agent. I've moved away from the installer location so cannot ask them, and in any case don't think they were Victron supremos.

One thing I've noticed is that the SOC percentage doesn't exactly match up with the consumed amp hours, e.g. the phone app shows 84% SOC and consumed Ah of -34.9 when my maths says it should be -32Ah. A small difference maybe, but if the Victron system is not accurate there could be issues affecting the batteries.

I've switched all my consumers in and out to see if any were not registering on the shunt. What else could be causing this problem?

Check the Victron BMV 200 "Battery Capacity" parameter is set to 200Ah under "Battery" in settings. If this is not set to correspond to your battery capacity the SOC reported will be incorrect.

 

[Stephen28]

The battery voltage versus capacity table in post 20 is for conventional lead acid batteries. If the battery is Enhanced lead acid type such as Yuasa L36-EFB the resting voltage will be higher

 

[PhilandMena]

That table corresponds to a conventional lead acid battery, the Yuasa L36-EFB is an Enhanced lead acid battery which has a higher resting voltage than conventional. Information on the A and N Caravan Services web site indicates a resting voltage of 12.3V corresponds to 50% state of charge for Yuasa L36-EFB.

My test was not conducted on a Yuasa EFB battery. It was conducted on an Exide ET650 Lead Acid battery, hence the correct chart for the test undertaken.

 

[Lenny HB]

The chart that you refer to above.

My voltage loss was less than 10% So I calculated 77 (Remaining Amps) divided by 90 (Volts) Multiplied by total Battery Amp Hours) 100 = 85.555 Which i calculate as remaining capacity. (12 56 volts is nearer 100% fully charged than 90 % so my remaining capacity may be even higher ? According to Alpha batteries when a batter has used 20 % of its capacity it is regarded as reaching its end of life. What a load of Boll***s. More marketing crap IMO

Remaining

That chart seems a bit optimistic, I always use this one.

 

[Lenny HB]

Check the Victron BMV 200 "Battery Capacity" parameter is set to 200Ah under "Battery" in settings. If this is not set to correspond to your battery capacity the SOC reported will be incorrect.

Also needs adjusting for age of batteries reducing approx 2.5% per year.

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[Raul]

The default 0% soc for a lead acid flooded is 1,75v per cell 10,5v for a 12v 6cell.
I would go with the chart Phil posted for a flooded. I use the same chart for my house bank and it correlates with the acid density as well.

 

[cmcardle75]

When you say you use 30Ah in a day, is this with the fridge off? A compressor fridge will use this by itself in that time, let alone any other loads. Are you sure the current measurement is accurate? I'd expect to use at least twice that much in a day, what with lights, pumps, TV, charging etc.

 

[Raul]

Agree, I use compressor fridge myself and I expect 25-30ah per day for a compressor on the middle setting with freezer shelf out. I use 70-80ah daily with two compressors, pump, tv, lights, victron gear, router, and the rest.

 

[autorouter]

My voltage loss was less than 10% So I calculated 77 (Remaining Amps) divided by 90 (Volts) Multiplied by total Battery Amp Hours) 100 = 85.555 Which i calculate as remaining capacity. (12 56 volts is nearer 100% fully charged than 90 % so my remaining capacity may be even higher ?

Looks like the test is not working, then. If the voltage of 12.56 represents 90% charge level, then the theory says that the 23Ah that you drew from the battery represents 10% of the capacity, so the actual capacity should in theory be 23Ah/10 x 100 = 230Ah. It's supposed to be 100Ah. No idea why it didn't work. The rate of 4.6A is very near the ideal 5A rate which would discharge it in 20 hours, so it's not related to the Peukert factor.

 

[Raul]

That chart seems a bit optimistic, I always use this one.

View attachment 557966

Another thing to consider for the wide chart voltages, is acid mix. Apart of the various dopings calcium, carbon etc., it’s the acid specific gravity mix. The higher the concentration is, the higher the voltage reading. A agm can have 1,80 specific gravity acid, while flooded can be as low as 1,24. A hoppecke stationary tubular cell uses a acid mix of 1,24, that will give a 12,65v rested voltage fully charged. Trojan, Rolls Surrette, flooded uses 1,27 acid and the 12,65v + is considered fully charged. Also the surface charge to disparate fully, for a true reading, can take as long as 24hr rest depending on temperature. Automotive and leisure flooded, use a 1,28 acid mix, that’s exide, Yuasa etc. and a 12,7v + is fully charged.
There are advantages and disadvantages on both sides, a high mix gives good voltage reading, more stable on voltage sag, less resistance but, at the expense of high rapid corrosion and shorter life. A weak mixture gives lower voltage, but less corrosion and long life. The later is mainly found In stationary applications with big cells, with design life of 15-20 years.

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