Leisure Battery Test

[Terrytraveller]

I have the results of my old and expensive Elecsol battery bench test. I would be interested if others could make a similar test with a standard Leisure battery of similar age and report it, in an effort to cut through the sales patter about these batteries.

 

Elecsol 110 amp carbon fibre battery installed 03-06-2003

Fully charged until terminal reading was 14.56 volts. (should be 14.4 volts)

Load was 3.89 amps Panasonic G10 TV

After 5 hrs voltage down to 12.3 volts under load then rest for 12 hrs.

After 7 hrs voltage down to 11.89 volts under load.

 

I am obtaining a usable 46.68 amps from a 39 month old 110 amp Carbon Fibre battery. It’s widely reported that the usable power of all batteries is only half that of the rated capacity.

 

12 hrs at 3.89 amps equals 46.68 amps or 12 hours viewing of TV (3.89amps) without recharging the battery, the rest period helps the battery to recover slightly.

 

Regards Terry

 

[fred grant]

terry

how many of us is likely to had our batterys installed on 3rd june 2003?

 

AND if us did, how many of us is likely to remember.

 

shant ask how to test it. last time i touched a battery i nearly cuaght the barn afire!!!!!

 

fred

 

 

[Terrytraveller]

Hi Fred,

 

Thanks for your reply,sorry to hear you nearly burn't your house down >:-(

 

Any standard 110 amp battery that's had a few miles under its belt would do for a test, I know we've got a few technical bods on the forum, so was hoping for some input from them - eventually - as these tests take a couple of days to conduct.

 

It would be nice to get some hard facts on which is the best type of battery to use, i.e Standard, carbon fibre, AGM flooded cell or Gel, based on useful life and power output available.

 

Magazine reports are often superfical and based on manufacturers data, on a forum like this its possible to get some real time info - hopefully.

 

Regards Terry

[Guest starspirit]

It's not meant as a put down Terry as your test is an admirable piece of work but experience suggests that there are as many discrepancies between 'identical' batteries of the same make as there are between different types and makes?

 

Why else would some batteries last 6 years and some less than one, neither extreme being uncommon?

 

So I guess makers can rest easy that their claims can never be proven or disproven.

 

Just like 'official' fuel economy figures for cars?

[Clive]

I did a discharge test of the 160 ampere hour 6 volt standby batteries we currently use as these were "donated" to me having served one life (5 years) at London Air Traffic Control as part of a 48 volt backup set for a bit of kit.

I used a 55 watt Quartz hallogen driving lamp as the load and wired this in series with an ammeter. I also fitted a digital volt meter across the two 6 volt units. I terminated the test after 150 ampere hours had been removed and the terminal voltage was 11.5.

That was good enough for me.

 

Terry, if the battery is fully charged (three stage charger) then you can expect to get all of the rated capacity if your discharge current is no more than one twentieth of the ampere hour capacity.

Discharge it fast and the effective capacity will fall.

 

If its down to half capacity at a slow discharge then replace the batteries. Their internal self leakage will also be high at this time.

 

If you want good batteries try golf cart traction batteries.

 

Carbon fibre batteries tolerate over discharge and leaving batteries discharged better than conventional batteries. Thats tolerate, they are not totally imune to this abuse.

 

Its good policy never to discharge a battery below 20% as this prolongs their life.

 

Also an overnight charge with a simple charger which limits at 14 volts will only put in about 80% of the total charge - but topping up requirements will be minimal.

 

Good luck

 

C.

 

 

 

 

 

 

[Terrytraveller]

Hi Starspirit,

 

Thanks for your reply, I think the only discrepancies you should see between 'identical' batteries of the same make would be caused by age or treatment. Normally you would change a battery when it starts letting you down, the sensible course to take is to evaluate your battery perhaps before the MH season begins, not that we all are that bothered perhaps.

 

I understand batteries will last for some time in some instances, if they are in the MH they will be subjected to an intermittent charging regime from either or all of solar panel, alternator or the MH's own mains charger, and you really never know how efficient your battery is.

 

When asked about battery usage i.e How long will a battery last if we are off hook etc? I always advise charging the battery fully, bearing in mind all MH chargers do not take the battery up to 14.4 volts, the optimum charging voltage for a flooded cell, but merely to 13.8 volts which charges the battery to only 80%, and place a known load on it.

 

So decided to take my own advice and find out exactly what my battery is capable of supporting. Also whether or not it will reach the voltage necessary to turn off or turn down the various regulators in the charging systems, if I were to but a new battery in parallel with it.

 

I have found sometimes a battery with a bad cell will still rise to 14.4 volts so turning off a regulator, seemingly indicating a good battery, but the battery voltage will drop very quickly again after several hours without load to 11.5 volts perhaps. So the only meaningful test would seem to be one of endurance. I bet Clive has got alot of useful information on battery capacity, while sitting up to all hours CQing trying to get those elusive countries, perhaps we can entice him into the thread as well?

 

As always all contributions to the thread gratefully received.

 

Regards Terry

 

PS How about that? no sooner had I written and Clive was there - How do you do it - and whats the next lottery numbers - I just noticed that you replied before I hit the submit button, so will be reading you any minute now! (lol)

[Guest peter]

I can reccomend Chloride batteries. As these were original equipment on my boat and one of them lasted 14Yrs and the other 3 about 9 Yrs.

[Terrytraveller]

Hi Peter

 

Thanks for the info on your setup, fourteen and nine years is a fantastic amount of time for a battery to last, I wonder how/why? - salt air perhaps?

 

Hi Clive,

 

That's a good result from 160amp battery, 150 amps of endurance at around 20% discharge rate.

 

Okay on 3 stage chargers, what exactly are the stages - do you know?

 

I have the Morningstar SS10 solar regulator on the end of an 85 watt panel as seen at http://tinyurl.com/2fg9ce there is a manual and data sheet on the page too , this uses PWM regulation, sort of variable mark to space voltage regulation all dependant on battery condition, would you consider this the same as three stage charger?

 

Regards Terry

[Clive]

Hi Peter,

My batteries are Chloride.

 

Terry,

A three stage charger will firstly limit the charge current to a safe value. As the battery charges the terminal voltage will rise. The charger will allow the voltage to go up quite a bit above 14 volts for a while (14.4 or 14.6 being typical for a motorhome system) then reduce the charging voltage to something a little less than 14 volts, 13.6 - 13.8 being typical. This to ensure that prolonged connection to a hookup (or solar panel) does not cause continued gassing.

 

The maximum voltage depends on the software algorythem in the inteligent charger which would be different for GEL or WET cell batteries. Recent research suggests that a higher voltage is used for GEL batteries than WET cell batteries but as yet I havent got an answer I can understand as to why its this way round. I would expect wet cell batteries to take a higher voltage as you can top up the electrolyte on these to make up for the gassing. Gel cells don,t have this option!

 

I must talk to the resident Chloride man at work!

 

Interestingly Traction batteries are taken to much higher cell voltages during charging but unlike a motorhome these batteries are NOT connected to the leisure electrics while on charge. Automatic watering systems are used to compensate for the gassing.

 

I also know that one of the leading suppliers of electrical systems for UK motorhomes has on offer a split controller/charger. When on hookup one power supply runs the leisure equipment in the van at say 13 volts while another power supply charges the leisure battery quickly including the high voltage phase. This method ensures that Leisure equipment is NOT subjected to high voltages. Nifty!

 

 

Terry, just looked at the link. Its uses PWM to control the charge rate but it does not say what algorythm it uses, so duno. It sounds prety standard to me.

 

 

[Terrytraveller]

Hi Clive,

 

Many thanks for your kind and comprehensive reply. I've mentioned before that the elecsol battery uses around a litre of water per annum and has got to caused by excessive gassing.

 

On a bright days as today, the battery voltage is over 14.5 volts and I have seen it as high as 15.1 volts at midday, the off load 85 watt array voltage is 19.5 volts at that time without disconnecting battery (battery fully charged), removing the solar input from the regulator brings the array voltage up to 22.5 volts, it seems very efficient at converting the light to power.

 

At 15.1 volts the battery was accepting 0.4 amps, so no more than a very small trickle charge.

 

I make the above observations as I know more than a few people have asked about load and off load array voltages, when trying to trouble shoot their system.

 

I do have the option of dropping the output voltage down by strapping it to the Gel type battery, charging at 14.1 volts instead of 14.4 volts, I think I must try this first and see how it goes.

 

Seems strange that new research is indicating Gel to be charged at a higher rate than wet batteries.

 

After my Elecsol endurance test, I left the battery over 24 hrs and the voltage remained at 12.8 volts - 12.9 volts, I hope that this is indicating there is no internal leakage and the battery is good, even though I only obtained 46 amp hrs from it, perhaps due to the type of charger used not charging the battery to 100%.

 

Regards Terry

 

[Clive]

Hi Terry,

I am a little suspicuous of your regulator with a measured voltage of 15.1 volts, its a tad high for a system that remains connected to the vans leisure circuits. If you said it topped out at 14.4 or 14.6 I would be less concerned. However what you need to be sure of is after the voltage has risen to this high value and the charge current fallen to a low value does the voltage then fall to a maintaining level of about 13.8 volts when the sun is still shining? This would explain your consumption of de-ionised water. Solar regulators are not expensive, have you considered swapping it for another?

C.

 

[Terrytraveller]

Hi Clive,

 

Thanks again for your reply.

 

I have just checked the regulator output and it reads 14.6 volts to two 110 amp Elecsol parallel ( one 3.5 yrs old and one brand new), they are both receiving 1.6 amps equally from the solar regulator, the array is in bright sunshine and the regulator input from the array is 15.6 volts while supplying a charge to the batteries, so surplus power is available from the array at the time of the test.

 

The 15.1 volts at the battery terminals mention before was in the summer, very hot, sun overhead on the Med. The answer to the seemly over voltage, maybe due to the battery position under the MH in a box below floor level and cold, the regulator mounted near the ceiling inside the MH by the door and very hot, but within operating tolerance.

 

Would this extreme configuration cause the regulator compensation to pump more current/voltage into the battery, ie Hot regulator and cold battery. I must admit I didn't fully read or understand at that time, the importance of placing the regulator and battery in the same location. I always like to see the little green charging light on the regulator *-)

 

If you have time to comment on the above, I am sure it will help others when installing a new Solar system, also will confirm or not, if in your opinion, I am on the right track.

 

Regards Terry

[Brambles]

Terry, If the regulator has voltage compensation for temperature then if anything the charge voltage should drop as it get warmer. This is because the internal resistance for a lead acid battery falls as it gets hotter.

 

Jon.

[Terrytraveller]

Hi Jon, Thanks for the reply.

 

Sort of see what you mean - Say if the output of the Regulator was a constant for a moment in time - and if the battery resistance was higher because its colder than the regulator expects it to be, the battery would oppose the current from the regulator, would not the voltage across the battery increase as current flowing falls?

 

I am not saying I am right - it's just a thought.

 

The regulator used is on http://tinyurl.com/2fg9ce .

 

Regards Terry

[Dave Newell]

There is a very good and very simple reason for the regulator being mounted near to the battery....Voltage Drop! If your reg is mounted nearer to the array than the battery then the longest run of wiring is in the lower (regulated) side and any drop caused by the length of the run will result in lower charge voltage at the battery. Because the array produces upwards of 16 Volts it makes sense to put the regulator near to the battery, that way any volt drop is in the higher side of the wiring but this still gives a higher voltage at the reg than the required output meaning the reg can do its job properly.

 

D.

 

Oh yes Terry, I suspect the reason you got such a low AH figure for your battery is you didn't fully discharge it. 12 Volts is not fully discharged especially under load. You really need to go down to around 10.5 Volts under load to acchieve complete discharge.

 

Of course this will do your battery no good at all!!

 

D.

[Brambles]

Terrytraveller - 2007-03-27 5:29 PM

 

Hi Jon, Thanks for the reply.

 

Sort of see what you mean - Say if the output of the Regulator was a constant for a moment in time - and if the battery resistance was higher because its colder than the regulator expects it to be, the battery would oppose the current from the regulator, would not the voltage across the battery increase as current flowing falls?

 

I am not saying I am right - it's just a thought.

 

The regulator used is on http://tinyurl.com/2fg9ce .

 

Regards Terry

 

Hi Terry,

Errrmm!!! yes voltage could rise if the regulator was trying to supply a constant current.

If the reg was constant voltage, then no, the current would fall and voltage stay the same.

J.

 

P.S. away now to look for spec of your regulator.

 

[Brambles]

Terry, what speciific model of regulator do you have,and what is the model/type solar panel?

Also noted the temperature compensation of regulator is minus 28mV per degree C.

Jon.

[Guest peter]

Hi, talking about off topic, How is the weather down your way, been brilliant up here the last week so planning the next trip.

Can you still get Topics? I know they're not in the Celebrations selection any more. Perhaps people have gone off Topics.

A hazelnut in every bite init!

I couldn't agree more. By the way everyone, what do you think about this bloke at Barclays who's earned 22 mil?

He a fortuitous codger I reckon - severe case of right place right time.

Glad I don't bank with Barclay's or I might be disposed to dispose of them too.

I've started many topics and watched as the conversation wanders off and on and off again but due to my enduring capacity for tolerance I would never dream of grumbling.

By the way interesting programs on death on TV this evening - any comments anyone?

Why a message to the moderator?

Does he/she/they/them/it keep going off topic? a hazelnut in every bite" I thought that was squirrel s***!

Shame.

Perhaps that is why yoy can't seem to get them now.

Spel chec doesnt wurk.

Like the new avatar starspirit.

Much more you.

Thanks Dancer - she's not as ruff as me.

At least you can pick up dozens of free pens in Barclays.

I wonder what TOP GEAR will get up to next series?

No will, I'm talking whole hazelnuts, not chopped, minced or partly digested.

Totally agree with the Moderator and much as I hate to admit it sometimes he is the only one on here making any sense at all.

Careful Richard, them nuts'll repeat on yer!

All this talk of chocolate with nuts in reminds me, I never did work out why they changed the name of Marathon to Snickers. Very unfortunate if you forget things in shops very easily and have to keep repeating under your breath what you came in for. Try it.

And Opal Fruits to Starburst - what was that about?

And Jif to Cif (and what the heck does "Cilitt Bang" mean? Sounds vaguely obscene!)

Rant over - now I've given you all lots more excuses to get off thread. usual.. europeanisation! They changed the names to the names used in rest of Europe.

in the case of the sweets I was told it was for the USA's benefit, and Cif / Jif was in case someone tried to squeeze white cleaning stuff on their pancakes [ def sounds like USA]

I preferred Lion bars myself, proper thick licorice and licorice root, and kali [?] made your finger go a funny colour tho

Have you ever tried the usa versions of out chocolate bars, like snickers and mars etc.. They taste really sicky like, as if they have gone off. (LOL a gone off Topic). I believe it is something to do with cows being grain fed and not grass.

Anyway, TO GET BACK ON TOPIC please, can you still actually get Topics, Not sure if you were joking or not.

P.S. Peter, please post again to show there are no hard feelings and you see the funny side. Just all a bit of banter and light heartedness to help life tick along sweetly.

I think maybe Peter has got the hump with all of us for partaking of the Michael and consistently showing a juvenile sense of humour. Hows about Mr Moderator rearranging the home page so that the various areas of interest are listed in order of poularity?

Motorhome Matters FIRST followed by Chatterbox and all the other also runs following on in rapidly diminishing order.

Well Pete - guilty as charged - and proud of it too.

I suppose it's nothing less than expected when you reach senility Richard.

 

[Guest starspirit]

Very clever Peter.

[Terrytraveller]

Hi Dave,

 

Thanks for your input, I did consider the run from the regulator to the battery, it's around seven feet so I used fairly heavy cable, 79 strand by 0.2mm twin flex almost twice the thickness (but not as thick as someone who has posted some non technical gibberish on this thread!) of normal 10amp auto cable.

 

I didn't like to run the battery down to a fully discharged state, but more to a level which would not damage the battery, that's why I used the Panasonic G10 TV as a test, it cuts off at 11.5 volts. I must admit I did turn the TV off prematurely when the battery voltage was 11.89 volts, I probably would have got a few more hours out of it.

 

 

Hi Jon,

 

Thanks again for your contribution, The Solar Panel is a Sharp 80watt Module, bought end of 2004 for £330, the regulator is MorningStar SS10L as seen at http://tinyurl.com/22m6fl .

 

Ok on the temp compensation is -28mv per deg C, a temp differential of only 25c would make a difference of around 0.7 volts, which would give me a reading of 15.1 volts instead of 14.4, so it seems you have cracked it, we have an explanation.

 

Peter,

 

I won't thank you for your input this time, buts it's nice to know you have finally got the hang of the Copy and Paste procedure, but its no substitute for putting together your own sentences.

 

Regards Terry

 

[Brambles]

terry, hate to say this but the temp coeficient has not cracked it.

 

At 20degrees the voltage will be 14.4 say.

At 55 deg C voltage 13.7 (14.4 - 0.7)

So unless you were in the med and it was freezing around the regulator then its not correct what you have worked out.

Jon.

[Brambles]

"On a bright days as today, the battery voltage is over 14.5 volts and I have seen it as high as 15.1 volts at midday, the off load 85 watt array voltage is 19.5 volts at that time without disconnecting battery (battery fully charged), removing the solar input from the regulator brings the array voltage up to 22.5 volts, it seems very efficient at converting the light to power.

 

At 15.1 volts the battery was accepting 0.4 amps, so no more than a very small trickle charge. "

 

 

Terry, there is something wrong here. With the regulator off load (fully charged you have 19.5 volts. With battery disconnected you have 22.5 volts. Now unless you had some other load on the regulator output then you should not habe has an increase in aray voltage. Also 0.4 amps is far too high for a trickle charge (0.04A would be more like it).

I suspect a faulty reguator now. Back home in this poorer sunlight you may only be getting 15 and bit volts from array so may ony be taking battery up to 14.8 or so as a result. Got a shorted FET transistor in regulator is my guess. Time to test the regulator with seperate power supply. I could be wrong, but it would explain a lot of your anomalies.

You also mentioned using TV as it cits off at 11.5 volts. Your regulator cuts of at 11.5 volts ( the L model).

 

Your array is 80 watts max so no problem their with too much current and also has a 10 Amp fuse according to spec.

 

Oh Hum!

Jon.

 

 

[fred grant]

us spent hours reading all the above and us is none the wiser. Do know clive's lottery number tho, so us can be of sum use to all you bright forum members!!!!

 

5 15 29 51 59 62

 

fred

[Terrytraveller]

Hi Jon,

 

Thanks again for your reply. Satisfying the easy point first, I don’t use the 10 amp load disconnect output, the habitation load is taken directly from the battery via the normal factory fitted 12 volt distribution system.

 

Granted there is discrepancy between what I call off load battery connected and off load Array disconnected. With that statement I am accepting the light strength variations and battery consumption effect between sampling will alter, it was/is my theory this would account for voltage discrepancy of 3 volts between OC Array and fully connected but ‘off load’, or am I taking the easy way out?

 

I take your point that I may have a failing Regulator, although it seems fairly consistent over the three years of use – i.e. making my batteries thirsty, but with seemingly no other ill effects. I am hoping that by putting another battery in parallel, as well as giving me more capacity will reduce the over gassing and the need to water them frequently.

 

Regards Terry

 

 

My Dear Fred,

 

Sorry if we are being a bore – I will try to pick a more interesting subject for you – I notice you are interested in ;-

 

dry stone walling, home brew, steam up, ferreting, eating oggies, me jr terrier, chapel, going up cambourne hill coming down and orgies.

 

Such a lot to choose from – we have exciting times a coming

 

I also see your Avatar is illustrating vintage busses is that one of your hobbies? – are you the owner of such a fine vehicle?

 

Incidentally – the lottery numbers only go up to 49 my wife says – please check again with Clive – it is important we get it right!

 

Regards Terry

 

 

[Brambles]

Terry,

 

Have you mentioned batteres being thirsty before and gassing,

 

Oh Hum - faulty regulator.... looking more like it all the time... or connected wrong which I am sure it is not.

 

Jon.