Mains Charger For Leisure Battery Advice Please!

[mac74]

Hello all, i have just bought 2 x 100ah L36-EFB Yuasa wet lead acid batteries from tayna batteries yesterday, (previously i used L35-115 x 2) and i was wondering if my ctek msx 5.0ah was up to the task of charging these new types??? ( i had to give them a top up as they where 12.6v when they arrived, now the 1st one is 13v after a 8hr charge and a 8hr settle) I say this because looking at back posts about chargers, a battery guru on this forum says that the ctek chargers do not charge the batteries up, past 80% of their capacity? (the manual also refers to the 80% charge point) He also says that the ctek are more designed as a car battery charger (not leisure batt) given that 70% is all that is needed to start a car up? I also understand that as a rule of the thumb, ideally a 10amp charger is more suited for a 100ah batt, but i am not bothered about the faster charge up time. So is this 'faster charge time' the only benefit of a 10amp charger over my 5amp? And is mine up for the job? I am a window cleaner and i draw say 10amps per hour, off/on for about 4 hours with my shurflo pump, so i was thinking that i may not go to below the 50% capacity ideal rule? but i do know they are gauged on the 20hr discharge thing, so im not sure? (i rotate them every morning, off mains charge straight to van) I also have a split charge relay connected in van whilst im driving, but as my work is so compact, im not putting much amps back in due to short driving times, however im thinking that i may disconnect this for the first hour of my work day, so i dont over cook battery once ive mains charged it? I thought i would ask these questions on here, because as a caravan'er myself i was thinking that people on here will be more clued up on this leisure battery tech than anywhere else? Please help if you can? Many thanks m

[spirou]

I don't know the charge profile of your CTEK but if it's anything like my car battery charger it will cut off the moment it reaches a certain voltage (probably 14.4V). This is just the first "bulk" stage, at which point a proper leisure battery charger would continue for several hours in the so called absorption phase which maintains the preset voltage but the current steadily drops.

 

So if your CTEK only does the bulk phase then yes, the batteries never really get a full charge.

 

In your case, since you're taking batteries out every day, I'd consider one of the 10-20A Victron BlueSmart chargers. There's even a waterproof version if it's relevant for your business. https://www.victronenergy.com/chargers

[Keithl]

Looking on the CTEK website an MXS 5.0 does have both Bulk and Absorption phases stating that Bulk raises the charge to 80% and then Absorption to 100%.

 

https://www.ctek.com/products/vehicle/mxs-5-0

 

 

Link to MXS 5.0 Product Sheet

 

Keith

 

PS I have deleted your identical post on Caravan Chat to ensure all answers stay in one thread.

[aandncaravan]

Malcolm, The behaviour that many attribute to a charge/battery combination is when they are new. Once the battery ages a little. the behaviour changes.

 

So you may find conflicting advice dependent on whether the person is describing 'Laboratory' behaviour or real world use.

 

When a battery is new it is easier to charge so a smaller charger might be able to get it more fully charged than when the battery is a year or so old.

Most of the guidelines say the charger should ideally be at least 1/10 the battery capacity, 10amps for a 100Ah battery.

 

 

The technology of the battery has an impact as well, the Yuasa L36-EFB charges 1.7 times faster than a conventional battery, on the correct specification charger. It obviously won't on a 5amp CTEK.

Some batteries need to charge quickly for maximum life.

 

For example Concorde state that when regular cycling of their AGM's, the charger should be 20amps per 100Ah battery, or, "the cycle life may be negatively affected".

See docs below.

Sorry I can't attach the file it is too big but you can find it near the bottom of this page : http://www.aandncaravanservices.co.uk/how-does-a-charger-work.php

 

 

Most of the smaller CTEK's we have seen are Car battery chargers, for occasionally use, not designed to charge a big battery every day.

 

 

Hard to know the exact scenario as there are so many variables, of which temperature will play a part. but my guess would be that the Yuasa batteries will slowly degrade on a CTEK 5a Car battery charger, becoming harder to charge, so not charging fully and degrading faster.

 

 

 

[mac74]

Thank you for all replys, just wondering a few things? 1. what would happen if i used the 14.7v agm setting to charge them? 2. If i used a 100ah efb twice a week @ 50% take out, & re-charge, how often should i do a recon charge? 3. Also what 10amp charger would you recommend for say around £120 ish? (msx 10amp?) OR is the trade off, of buying a new charger outlay worth the little extra life of my batterys going forward? or stick with my ctek msx 5amp?

 

All opinions welcolme, Thank You.

 

Best Regards

 

Malcolm

[Derek Uzzell]

A CTEK MXS 5.0 User Manual is here

 

https://images-eu.ssl-images-amazon.com/images/I/A1vkGMqHULS.pdf

 

and information on the charging programs is on Pages 4 and 5.

 

If your CTEK MXS 5.0 adequately charged your two 115Ah Yuasa batteries previously and the charger setting and the frequency of charging you used with those batteries did not noticeably harm those batteries, I would have thought there is no obvious reason to change what you’ve been doing in the past nor any need to spend money on buying a new charger.

 

Rather than complicate matters by attempting to optimise the charging procedure by using the cold-weather/AGM charging program when it’s not cold and the Yuasa battery is not an AGM type, or using the reconditioning program more frequently than CTEK recommends, just follow CTEK’s advice in the table on Page 4...

[aandncaravan]

Derek, but did he optimise the charging of the old batteries, or did they have half the life that might be expected? I don't think that is a question anyone can answer now, but no reason not to try and get the best from the new batteries

 

 

Malc, You will note the symbols in the manuals show a car or mororbike only, showing what they are designed for.

 

Many battery manufacturers are suggesting a reconditioning charge will do more harm than good, so we woudn't reccomend you do one at all.

 

 

Yuasa have said that the L36-EFB can take a slightly higher charge voltage for short periods, but i am not sure that would be good for the battery long term?

 

The lowest spec Motorhome charger we would recommend would be a Sargent PX300 21a charger and they are about £120.

 

 

CTEK are not battery manufacturers and some of their 'marketing' claims, like claiming the chargers can recover Sulphated batteries etc is at odds with the likes of Victron who are both charger and Battery manufacturers and have been for many years.

 

 

The CTEK marketing claims,

"STEP 1 DESULPHATION

Detects sulphated batteries. Pulsing current and voltage, removes sulphate from the lead

plates of the battery restoring the battery capacity".

 

Yet any battery expert will tell you that only 'soft' sulphation, built up over a recent short time interval, can be reversed. The usual 'hard' sulphation cannot be recovered and battery damage will usually result if you try.

 

As for step 6 of deliberately overcharging a battery to make it Gas is crazy on a Leisure battery. Even a short period is going to cause damage =

"STEP 6 RECOND

Choose the Recond program to add the Recond step to the charging process. During the

Recond step voltage increases to create controlled gassing in the battery. Gasing mixes the

battery acid and gives back energy to the battery".

 

Victron are giants in the battery and charger world, have a look at their approach to Sulphation, etc.

 

 

Sorry but we have opened too many CTEK chargers to be impressed. In my view overpriced and underperforming compared to the competition, but very clever marketing.

 

 

 

[aandncaravan]

One last thought -

My Alternator doesn't 'desulphate' or 'recond' my Starter battery in my car yet it had a 12 year life.

 

 

A Stop Start/Brake energy recuperation vehicle has got extremely sophisticated Alternator control, but no 'desulphation' or 'recondition' phase. If these features did extend an AGM batteries life wouldn't they have been incorporated into the ECU/Alternator charge program to try and get a bit more than an Stop/Start AGM's miserable 4 year life?

 

 

So how essential are these 'features', really useful, or marketing?

CTEK were the first big charger manufacturer to extol their virtues and make us think we all needed them.

[mac74]

Very, very interesting info guys thank you, but what would the Sargent PX300 21a charger do, that the ctek msx 5.0 dosen't? apart from speed (just asking, & interested) and what is your take on the victron 10amp blu chargers? i like the idea of the bluetooth monitor on these. For info purpose only, the history on my two L35- 115's / ctek msx 5.0 charging is as follows: A 100psi pump 4-5hr use @ 16amp max ( but the intelligent elec controller i have fitted, cuts power to pump when volt draw goes up i.e dead end detection/ tap turned off, it also has a digital read out telling me what the voltage is on batt, and under load, so i reckon 10amps in real terms. I think i drain max 50% ish draw from full charge @ 12.7v, and say 50 amp ish out. I also van split charge relay involved @ 14.3v ish whilst driving around to work areas and then stop/start stuff, but im thinking no more than 30 minutes total driving over 4/5 hrs on/off, (should i ditch this s.c.relay?)

 

So in real usage terms, from the L35-115's i use maybe a 10/12amp ish draw? constant for 3.5 hours over the 4/5hr period, and the split charge relay puts in 14.3v for about 30 minutes over the same 4/5hrs. I wonder how this stacks up?

 

Sorry to go on lads, but im very interested in learning about all of this.

 

 

Best Regards All

 

 

Malcolm

[spirou]

Charging while on the move, no matter how short, isn't hurting the batteries so I see no reason to get rid of SCR unless you have other reasons to do so.

 

With the Victrons, no matter which model you get, you can limit the max current (and set many other parameters like temperature compensation, charge voltages etc.) all from your phone. So if you get a 20A model you can limit the current to ~10A when charging the single 100Ah battery, or set it at 20A when you need to charge both (or bigger battery in the future).

[mac74]

spirou - 2019-03-27 9:40 PM

 

Charging while on the move, no matter how short, isn't hurting the batteries so I see no reason to get rid of SCR unless you have other reasons to do so.

 

With the Victrons, no matter which model you get, you can limit the max current (and set many other parameters like temperature compensation, charge voltages etc.) all from your phone. So if you get a 20A model you can limit the current to ~10A when charging the single 100Ah battery, or set it at 20A when you need to charge both (or bigger battery in the future).

Keithl above says - Looking on the CTEK website an MXS 5.0 does have both Bulk and Absorption phases stating that Bulk raises the charge to 80% and then Absorption to 100%.

[Derek Uzzell]

Malcolm

 

May I ask why you chose to replace your pair of 115Ah Yuasa L35-115 batteries with a pair of 100Ah Yuasa L36-EFB batteries, please?

 

An L35-115 battery is advertised by Tayna for about £93, whereas Tayna’s price for a L36-EFB battery is about £119, and both are marketed by Yuasa as ‘leisure’ batteries with an engine-starting capability.

 

As your window-cleaning work involves using the batteries and the SHURflo water-pump differently from how both would be operated in a leisure-vehicle, if the L35-115 batteries proved adequate for your work and you managed to get a reasonable lifespan out of them using your CTEK MXS 5.0 charger and your van’s split-charge relay approach, what advantages do you anticipate getting from changing things for the L36-EFB batteries?

 

It’s impossible to satisfactorily resolve an equation that includes more than one unknown value and what you are doing involves several unknowns. It seems to me that, although there are forum members here who have considerable expertise relating to motorhomes and how use of those vehicles’ leisure-batteries can be optimised, you uniquely have practical experience of using and charging 12V batteries to drive a water-pump for professional window-cleaning.

 

If you want to spend money buying a different battery-charger that’s your choice, but if your CTEK charger is working properly and a higher than 5A charging rate is not a priority for you, I really can’t see what you’d gain.

[mac74]

Derek Uzzell - 2019-03-28 8:51 AM

 

Malcolm

 

May I ask why you chose to replace your pair of 115Ah Yuasa L35-115 batteries with a pair of 100Ah Yuasa L36-EFB batteries, please?

 

An L35-115 battery is advertised by Tayna for about £93, whereas Tayna’s price for a L36-EFB battery is about £119, and both are marketed by Yuasa as ‘leisure’ batteries with an engine-starting capability.

 

As your window-cleaning work involves using the batteries and the SHURflo water-pump differently from how both would be operated in a leisure-vehicle, if the L35-115 batteries proved adequate for your work and you managed to get a reasonable lifespan out of them using your CTEK MXS 5.0 charger and your van’s split-charge relay approach, what advantages do you anticipate getting from changing things for the L36-EFB batteries?

 

It’s impossible to satisfactorily resolve an equation that includes more than one unknown value and what you are doing involves several unknowns. It seems to me that, although there are forum members here who have considerable expertise relating to motorhomes and how use of those vehicles’ leisure-batteries can be optimised, you uniquely have practical experience of using and charging 12V batteries to drive a water-pump for professional window-cleaning.

 

If you want to spend money buying a different battery-charger that’s your choice, but if your CTEK charger is working properly and a higher than 5A charging rate is not a priority for you, I really can’t see what you’d gain.

Yes im starting to think that a change of charger may not be THAT beneficial to me? I used my ctek msx 5.0 to top up the new EFB's when i got them (12.5v) and after a 8hr charge on each put them @13v, and after a 2 day settle, they are now both the same @ 12.85v. The 2x L35-115ah have lasted me nearly 3 yrs and i got a lot more cycles than the stated 80 by yuasa, which has been very good, but when they got low 12.3v i noticed a drop in performance on my pump under draw (the last 6mths). So the reason i went for the higher priced/lower ah, L36-EFB's 100ah x2 is because even though im losing 15ah capacity, the main benefits over L35's, is 200 cycles on these L36's and less of a power curve on this new EFB tech? They are supposed to be capable of delivering a higher deeper cycle before the power drop off? but if you do take them lower than the 50% capacity, i believe you will lose cycles on the 200 stated? (but 200 is a lot better than 80) They are also getting good reviews, but only time and usage will tell whether or not this is just sales bull? It worked out about £25 ish more per battery with 5% tayna discount, and i thought its worth a punt. Ive read that varta/bosch/exide will also be making EFB's this year? if so the new tech must be better???

 

Best Regards

 

Malcolm

[Keithl]

Malcolm,

 

I've got to ask, and it's probably more to the likes of Allan than you, but why not use the two batteries in parallel and recharge them both every night?

 

This way you would be halving the depth of discharge and hence potentially extending their lifetime.

 

Anyone care to answer?

 

Keith.

[aandncaravan]

The CTEK 5.0 manual states it takes 26 hours to charge a 110Ah battery to 80% charge, the last 20% is the hardest to put in to a battery and can take a long time, and one of the reasons charger manufacturers quote the 80% figure, not 100%

Once the battery ages, most smaller chargers will fail to get a big battery to 100%.

 

As I said above,

" Hard to know the exact scenario as there are so many variables, of which temperature will play a part. but my guess would be that the Yuasa batteries will slowly degrade on a CTEK 5a Car battery charger, becoming harder to charge, so not charging fully and degrading faster".

 

 

Keith yes you are right, if the batteries were coupled together they would probably last twice as long, but need 52 hours to charge up.on the CTEK 5.

[Keithl]

aandncaravan - 2019-03-28 5:17 PM

 

The CTEK 5.0 manual states it takes 26 hours to charge a 110Ah battery to 80% charge, the last 20% is the hardest to put in to a battery and can take a long time, and one of the reasons charger manufacturers quote the 80% figure, not 100%

Once the battery ages, most smaller chargers will fail to get a big battery to 100%.

 

As I said above,

" Hard to know the exact scenario as there are so many variables, of which temperature will play a part. but my guess would be that the Yuasa batteries will slowly degrade on a CTEK 5a Car battery charger, becoming harder to charge, so not charging fully and degrading faster".

 

 

Keith yes you are right, if the batteries were coupled together they would probably last twice as long, but need 52 hours to charge up.on the CTEK 5.

 

So would a 'better' solution be to use them as a pair, in parallel, and recharge with a C/10 charger, ie 20 Amps?

 

Keith.

[spirou]

That would probably be ideal as the cycles would be shallow and recharging reasonably fast.

[weldted]

I also have 2 Youasa L36-EFB 100 amp batteries in my Motorhome fitted August 2018. I use a Victron 30 amp Bluetooth charger if they need topping up when my 300 watts of Solar is not enough owing to weather conditions or the van is not driven. They needed a few cycles to bring them up to their full potential.

The benifit of this size charger is the rapid recovery up to fully charged state and then monitored to keep them fully charged without overcharging.

[mac74]

Keithl - 2019-03-28 12:04 PM

 

Malcolm,

 

I've got to ask, and it's probably more to the likes of Allan than you, but why not use the two batteries in parallel and recharge them both every night?

 

This way you would be halving the depth of discharge and hence potentially extending their lifetime.

 

Anyone care to answer?

 

Keith.

No sorry you misunderstand, i use one per day (rotated)

[Keithl]

mac74 - 2019-03-28 7:33 PM

 

Keithl - 2019-03-28 12:04 PM

 

Malcolm,

 

I've got to ask, and it's probably more to the likes of Allan than you, but why not use the two batteries in parallel and recharge them both every night?

 

This way you would be halving the depth of discharge and hence potentially extending their lifetime.

 

Anyone care to answer?

 

Keith.

No sorry you misunderstand, i use one per day (rotated)

 

Yes, fully understood, BUT if you used them both in parallel you would discharge less and extend their life.

 

Can you charge both overnight if you bought a 20 A charger?

 

And an added bonus, the voltage would not drop as much when under load so your pump would be more efficient.

[mac74]

aandncaravan - 2019-03-28 5:17 PM

 

The CTEK 5.0 manual states it takes 26 hours to charge a 110Ah battery to 80% charge, the last 20% is the hardest to put in to a battery and can take a long time, and one of the reasons charger manufacturers quote the 80% figure, not 100%

Once the battery ages, most smaller chargers will fail to get a big battery to 100%.

 

As I said above,

" Hard to know the exact scenario as there are so many variables, of which temperature will play a part. but my guess would be that the Yuasa batteries will slowly degrade on a CTEK 5a Car battery charger, becoming harder to charge, so not charging fully and degrading faster".

 

 

Keith yes you are right, if the batteries were coupled together they would probably last twice as long, but need 52 hours to charge up.on the CTEK 5.

 

Towards the end of the life with my old L35-115's, when i was in the middle of a work day, and had done say a 2 hr solid draw over say 3hrs off/on, the pump would not work properly, and the flow rate became very weak, when looking at my spring digital controller, the read out under draw (pump running) would be 11.4v, then turn tap off would go back to 12.3v. Then when i got back home and put the battery on charge, it would APPEAR fully charged back up within about 4hrs????? Would this mean the battery has lost most of its capacity over time? and this is what you mean about the ctek not working effciently enough for a leisure battery? OR is this normal given the near 3 year heavy usage of mine? and even if i did use a better charger, would there be that much in it Allan? BTW i charge them in my shed which has a oil filled rad in there on a thermostat, so it will never drop below say 15c if this helps.

 

Many Thanks M

[mac74]

Keithl - 2019-03-28 7:50 PM

 

mac74 - 2019-03-28 7:33 PM

 

Keithl - 2019-03-28 12:04 PM

 

Malcolm,

 

I've got to ask, and it's probably more to the likes of Allan than you, but why not use the two batteries in parallel and recharge them both every night?

 

This way you would be halving the depth of discharge and hence potentially extending their lifetime.

 

Anyone care to answer?

 

Keith.

No sorry you misunderstand, i use one per day (rotated)

 

Yes, fully understood, BUT if you used them both in parallel you would discharge less and extend their life.

 

Can you charge both overnight if you bought a 20 A charger?

 

And an added bonus, the voltage would not drop as much when under load so your pump would be more efficient.[/QUOTe]

 

Hello Keith, yes i did think of this as linking two up would give me a much bigger battery and less drain over the two together, BUT i only have room for one battery up to 115ah size :'( . Thanks m

[aandncaravan]

mac74 - 2019-03-28 7:56 PM

Towards the end of the life with my old L35-115's, when i was in the middle of a work day, and had done say a 2 hr solid draw over say 3hrs off/on, the pump would not work properly, and the flow rate became very weak, when looking at my spring digital controller, the read out under draw (pump running) would be 11.4v, then turn tap off would go back to 12.3v. Then when i got back home and put the battery on charge, it would APPEAR fully charged back up within about 4hrs????? Would this mean the battery has lost most of its capacity over time? and this is what you mean about the ctek not working effciently enough for a leisure battery? OR is this normal given the near 3 year heavy usage of mine? and even if i did use a better charger, would there be that much in it Allan? BTW i charge them in my shed which has a oil filled rad in there on a thermostat, so it will never drop below say 15c if this helps.

 

Many Thanks M

 

 

Malcolm, Compared to a motorhome where both batteries would be in use daily, yours have only been used every other day over nearly 3 years. Therefore each battery has less than 18 months use and if we take off the last few months that the batteries have under performed, it equates to just over 1 year per battery.

 

I think that is poor for two such quality batteries, so something isn't optimal..

 

 

 

 

 

 

[Derek Uzzell]

Rough maths, but let's assume Malcolm works 5 days per week and 40 weeks per year - that’s 200 working days per year or 600 working days over a 3 year period. Dividing 600 by 2 (because Malcolm rotates his batteries daily) means that each of his Yuasa L35-115 batteries was in use on 300 days and, if a day’s use followed by a day’s recharging counts as a ‘cycle’, then his L35-115s each managed 300 ‘cycles’ before showing clear signs of flagging.

 

As Yuasa L35-115s are ‘maintainable’ batteries, I’m going to assume that Malcolm kept an eye on their electrolyte-level and topped it up if this proved necessary, but I would have thought that - given Malcolm’s usage pattern for his 12V batteries and the purpose they are used for - a 300 cycles per battery ‘life’ was a pretty good performance.

 

 

Malcolm’s vehicle has room for only one battery and being able to charge the battery in a heated shed avoids the need to run a 230V hook-up cable to the vehicle. So, as it seems unavoidable for Malcolm to continue with what he’s been accustomed to do during the last 3 years, it really boils down to his original question about whether it would really be worth spending money on a different battery-charger. If it’s believed that buying a different battery-charger would provide genuine value-for-money benefits, then which charger should he buy and what would the cost be?

[aandncaravan]

mac74 - 2019-03-27 8:35 PM

 

 

So in real usage terms, from the L35-115's i use maybe a 10/12amp ish draw? constant for 3.5 hours over the 4/5hr period, and the split charge relay puts in 14.3v for about 30 minutes over the same 4/5hrs. I wonder how this stacks up?

 

 

Malcolm

 

 

Derek, I noted that Malcolm said 'almost' three years, which might be a few months less, and the batteries had clearly expired some time prior to that if the CTEK reported them charging up in 4 hours, hence my 1 year life per battery. So I think your figures are optimistic.

 

However, the batteries 90 cycles are at 50% DOD, a shallow discharge will yield a lot more.

 

Using the above quote I think Malcolm is drawing about 35Ah a day from 115Ah battery. That is a shallow discharge and something the Yuasa 115 should shrug off.

 

The inferior Hankook DC range achieve over 1,100 cycles when shallow discharging, see manufacturers graph below, but only about 90 cycles at 50% DOD.

 

 

I am guessing many of Malcolms 'cycles' would have been outside the BS EB50342 '80% capacity' criteria (as noted by poor drop off the last 6 months of both batteries) and if you make an allowance for those then the Yuasa's should exceed the figures in the graph by quite a margin.

 

 

I would expect the Yuasa 115Ah in the use above, to have very, very long life, but obviously depends on actual real world use.