What is the life of gel batteries? (32 Viewers)

[TheLifeofBrian]

Hi all,
Anyone any idea what could kill my gel batteries in only 18 months?
April last year I changed both batteries as the old AGMs had died - we got 110ah gel batteries from Alpha & they have been absolutely great all year but got to the Lincoln show Thursday (no ehu) & by Friday night they had both dropped to 11v
When the sun comes out they read up to 14v but turn a tap on & they drop like a brick to 12v
I've tried disconnecting one of them to see if it's just one dragging the other down but last night (Saturday) it dropped so low it turned the control panel off & the sun had been shining all day & the only thing plugged in was our 2 phones.

This is virtually the same thing that happened to the last pair of AGM batteries!
The only thing I can think is I tried the inverter (that is wired in) with a coffee machine but it wasn't big enough so turned it off.
It's a 600w pure sine inverter with a remote switch:

Other than that the Lincoln show is great

Any ideas anyone please?
Cheers Chris

 

[Richard n Ann]

Sounds like something could be draining them. Are they maintained at home?

Have you got a decent battery monitor that uses a shunt?

 

[DavidG58]

When you disconnected the batteries did you check the individual voltages with a meter. I suspect one has failed but that will drag them both down, if you connect the good one only it should see you through another night if you are staying

 

[StillGoing]

Hi all,
Anyone any idea what could kill my gel batteries in only 18 months?
April last year I changed both batteries as the old AGMs had died - we got 110ah gel batteries from Alpha & they have been absolutely great all year but got to the Lincoln show Thursday (no ehu) & by Friday night they had both dropped to 11v
When the sun comes out they read up to 14v but turn a tap on & they drop like a brick to 12v
I've tried disconnecting one of them to see if it's just one dragging the other down but last night (Saturday) it dropped so low it turned the control panel off & the sun had been shining all day & the only thing plugged in was our 2 phones.

This is virtually the same thing that happened to the last pair of AGM batteries!
The only thing I can think is I tried the inverter (that is wired in) with a coffee machine but it wasn't big enough so turned it off.
It's a 600w pure sine inverter with a remote switch:
View attachment 953502

Other than that the Lincoln show is great

Any ideas anyone please?
Cheers Chris

I don’t think 600W is enough to power a coffee machine. What is the power rating printed on the coffee machine?

 

[TheLifeofBrian]

At home it normally keeps topped up from the solar but it was plugged in the last week or so & a 2+ hour drive would have topped them up anyway, but we did watch the TV for a couple of hours Thursday night & then I noticed the voltage had dropped.
We spent 3 months away in it without ehu 50% of the time with no problems at all in the summer.
I can't find anything different draining them now that wasn't plugged in before....
It's all controlled by a CTEK system:

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[TheLifeofBrian]

I don’t think 600W is enough to power a coffee machine. What is the power rating printed on the coffee machine?

1300w
You are completely correct!
I plugged it in before I checked the wattage of the inverter the controller just buzzed & turned red

 

[Richard n Ann]

My 80ah gel is now over 5 years old and still going strong. It's main job is the compressor fridge then ceiling fan, water pump and phone charging x2

With the ceiling fan on all night in August it was discharging more, 45% I think was typical. But now it's cooled off at night it's managing great.

Your 2 gels should last years

 

[TheLifeofBrian]

When you disconnected the batteries did you check the individual voltages with a meter. I suspect one has failed but that will drag them both down, if you connect the good one only it should see you through another night if you are staying

Yes I tried that & they both read 12.7v so neither obviously bad. it's currently just on the one battery which turned the controller off last night.
I'm going to try the other battery today.

 

[Richard n Ann]

When the sun comes out they read up to 14v but turn a tap on & they drop like a brick to 12v

My solar is charging at 13.7v at the moment. Turned the pump on and it dropped to 13.6v
Looks like your solar can't supply enough current for the pump. How much solar have you got? Do you know what amperage it charges at?

 

[TheLifeofBrian]

My solar is charging at 13.7v at the moment. Turned the pump on and it dropped to 13.6v
Looks like your solar can't supply enough current for the pump. How much solar have you got? Do you know what amperage it charges at?

140w solar apparently which I think is working fine, we've lasted over a week recently without hookup & never run out of power before.
The symptoms are exactly the same as when the old batteries died - they show full voltage but just drop as soon as any load is on them.
I will test them on Monday when we get home as my lad has a proper battery tester.
I'm not sure on amperage & haven't got a clamp meter but it's now on my list of things to buy!

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[mitzimad]

Remember not all clamp meters do DC amps so check carefully

 

[TheLifeofBrian]

Remember not all clamp meters do DC amps so check carefully

Thanks - good advice

 

[Richard n Ann]

they show full voltage but just drop as soon as any load is on them.

You're probably seeing the solar charging voltage the batteries will be flat.

You can't test a leisure battery with a starter battery tester as it won't show you the capacity which is the important bit.

This is the clamp meter most of us use:

UNI-T DIGITAL UT210E 100Amp 600V AC DC CLAMP METER Multimeter True RMS VFC diode | eBay

1 Cloth Bag. 1 Gift Box.

www.ebay.co.uk

 

[EuroTrotters]

ours lasted 8 years, still some life left but upgraded to lithium to save a lot of weight

 

[Richard n Ann]

140w solar apparently which I think is working fine

You should get a charging rate of about 8 amps on a sunny day when the batteries are low.

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[Jev88]

Do you have the correct charging profile for the gels?

 

[autorouter]

The CTEK D250S charges the leisure battery from the alternator at 20A, and the CTEK Smartpass boosts this by another 80A to make 100A total. I don't know what size your two Gel batteries are, but I suspect that might be too much for them. For the best long-term battery life, the charging amps should be limited to C/5, where C is the battery capacity. So for two 100Ah gels, that would be 200/5 = 40A. A bit extra might be OK, but I think 20 + 80 = 100A might be too much.

 

[TheLifeofBrian]

The CTEK D250S charges the leisure battery from the alternator at 20A, and the CTEK Smartpass boosts this by another 80A to make 100A total. I don't know what size your two Gel batteries are, but I suspect that might be too much for them. For the best long-term battery life, the charging amps should be limited to C/5, where C is the battery capacity. So for two 100Ah gels, that would be 200/5 = 40A. A bit extra might be OK, but I think 20 + 80 = 100A might be too much.

Sorry, I don't understand how the smart pass boosts it by another 80a, where does that come from?
Is that the case for AGM batteries as well as GEL?
I don't suppose your here at Lincoln are you

 

[TheLifeofBrian]

0

Do you have the correct charging profile for the gels?

The EBL is set to GEL, I believe the CTEK doesn't have specific settings?

 

[Lenny HB]

Sonnenschine & Exide Gels last for many years unless miss treated. The 3 Sonnenschine Gels in our last van were still performingike new 2 were 8 years old & 1 7 years old.

Do all your chargers have proper Gel charging profiles?

Gels don't like high current discharges sometimes they survive other times they don't. Your coffee machine is taking nearly 3 times the max recommended current out of them.

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[TheLifeofBrian]

You're probably seeing the solar charging voltage the batteries will be flat.

You can't test a leisure battery with a starter battery tester as it won't show you the capacity which is the important bit.

That was measuring across the battery with a multimeter. Obviously I can't disconnect the battery to measure as the pump wouldn't be connected to drain it.
Sorry I don't understand about the starter battery tester & capacity?
My lad has a proper drop battery tester, as he services wheelchairs for a living, which I can use when I get home.

Sonnenschine & Exide Gels last for many years unless miss treated. The 3 Sonnenschine Gels in our last van were still performingike new 2 were 8 years old & 1 7 years old.

Do all your chargers have proper Gel charging profiles?

Gels don't like high current discharges sometimes they survive other times they don't. Your coffee machine is taking nearly 3 times the max recommended current out of them.

The coffee machine didn't even turn on - the inverter controller just buzzed & turned off straight away !
As I say the CTEK doesn't seem to have any settings & the EBL is set to GEL.

 

[autorouter]

Sorry, I don't understand how the smart pass boosts it by another 80a, where does that come from?

The D250S is a dual charger, with MPPT solar and a 20A B2B, charging from the alternator/starter battery. The lower left input is from the alternator/starter battery, the lower right output is to the leisure battery.

The SmartPass is an 80A B2B, the left input is from the alternator/starter battery (the 16mm² wire), and the right output is to the leisure battery (the 16mm² wire).

They both share the same input and output, and they are connected by metal bars instead of wire links.

The D250S will work fine on its own as an MPPT solar controller and 20A B2B charger. The Smartpass will work fine on its own, as an 80A B2B charger. When combined together they can both use the battery temperature sensor that comes with the D250S.

 

[autorouter]

My lad has a proper drop battery tester, as he services wheelchairs for a living,

Usually a drop battery tester is used to test a vehicle starter battery, which is designed to provide a few hundred amps for a few seconds to turn a starter motor. If you look at the battery spec, there will be a 'CCA' number, something like 'CCA 600A'. This is the 'Cold Cranking Amps' for turning the starter motor.

Leisure batteries usually supply a few amps for several hours, and the relevant number then is the 'Ah' capacity, ie the Amp-hours. So a 100Ah gel battery will supply 5 amps for 20 hours, after which it will be very flat. Many leisure batteries, including Gel types, are not very good at supplying or receiving high currents, and will be damaged over a period of time if amps values more than about C/5 are regularly used.

A drop battery tester draws a very high current, several hundred amps, for a short time, and measures the voltage the battery terminals drop to. This gives a good estimate of the battery resistance, which is a good indication of the general health of the battery. But only if it's a starter battery. A leisure battery like a Gel could easily be damaged by that test. And even if it isn't the results are not very meaningful for a leisure battery like that.

 

[Lenny HB]

The coffee machine didn't even turn on - the inverter controller just buzzed & turned off straight away !

I was referring to the fact that if you have been using the coffee machine a lot that could have led to the demise of the batteries.

 

[TheLifeofBrian]

The D250S is a dual charger, with MPPT solar and a 20A B2B, charging from the alternator/starter battery. The lower left input is from the alternator/starter battery, the lower right output is to the leisure battery.

The SmartPass is an 80A B2B, the left input is from the alternator/starter battery (the 16mm² wire), and the right output is to the leisure battery (the 16mm² wire).

They both share the same input and output, and they are connected by metal bars instead of wire links.

The D250S will work fine on its own as an MPPT solar controller and 20A B2B charger. The Smartpass will work fine on its own, as an 80A B2B charger. When combined together they can both use the battery temperature sensor that comes with the D250S.

Ok I see thanks. Is there any way to limit the output from the 2 controllers - I thought they were supposed to control their output and go into float mode etc once charged (from what the instructions said) or is that only on EHU?

Usually a drop battery tester is used to test a vehicle starter battery, which is designed to provide a few hundred amps for a few seconds to turn a starter motor. If you look at the battery spec, there will be a 'CCA' number, something like 'CCA 600A'. This is the 'Cold Cranking Amps' for turning the starter motor.

Leisure batteries usually supply a few amps for several hours, and the relevant number then is the 'Ah' capacity, ie the Amp-hours. So a 100Ah gel battery will supply 5 amps for 20 hours, after which it will be very flat. Many leisure batteries, including Gel types, are not very good at supplying or receiving high currents, and will be damaged over a period of time if amps values more than about C/5 are regularly used.

A drop battery tester draws a very high current, several hundred amps, for a short time, and measures the voltage the battery terminals drop to. This gives a good estimate of the battery resistance, which is a good indication of the general health of he battery. But only if it's a starter battery. A leisure battery like a Gel could easily be damaged by that test. And even if it isn't the results are not very meaningful for a leisure battery like that.

Oh I see what u mean. To be honest I can't remember if it was a drop tester he had that we used last time - thinking about it I think it slowly discharged & then charged the battery as it took several hours to check. I think I might have got mixed up with one my dad has which basically just shorts the battery with a large load & is quite prehistoric!
Am I right in thinking that the controller we have - Hymer LT95F will turn off when the voltage drops below about 11v so after that nothing can flatten it any more? That seemed to be what happened last night & when I turned the control back on this morning it showed 13.5 again, presumably from the solar charging it.

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[autorouter]

A 600W inverter would take around 50A to 60A at full power. So not ideal for two 100Ah gel batteries, but not a great problem if only used occasionally. Fine for charging ebike batteries, for example. As already said, a 1300W coffee machine is way OTT, but I don't think that's the problem here.

 

[AdrianChen]

The only issue with Gels that I have heard of (and a few years back so may not apply to new stuff like carbon gels....) is that they can "boil" if they are charged too fast at too high voltage, ie bubbles form in the gel electrolyte, that then don't move and are present for evermore, if against the battery plates the capacity is reduced, so it's important to charge, within the battery's specification. the Ctek having a set profile covering LA to AGM runs at 14.4v, so may be pushing the Gels a bit too hard, but I do not know the spec of your batteries.

There were a few CBE systems that I have read about on different forums that had been (factory?) set to an AGM charging profile. This wrecked the standard fitted Gels pretty quick but there was a bad egg smell which I presume you don't have.

A proper capacity check will hopefully prove they're fine, and just take plenty of time to charge compared to your old AGM's.

 

[autorouter]

Ok I see thanks. Is there any way to limit the output from the 2 controllers - I thought they were supposed to control their output and go into float mode etc once charged (from what the instructions said) or is that only on EHU?

Yes they do, but not right at the start of charging. The three main charging stages are bulk, absorption and float.

In the bulk stage, the charger pushes out its full output amps, and the battery voltage rises a bit, but not as high as the absorption voltage of 14.4V. This continues at full amps output maybe for several hours, with the voltage gradually rising until it reaches the absorption voltage. At that point it flips to the absorption stage.

In the absorption stage, the voltage is held constant at the absorption voltage, and the amps gradually falls from the full output value to a predefined limit called the tail current. Usually about 10% of the full output amps. When the amps has dropped as low as the tail current, it decides the battery is fully charged, and flips to the float stage.

In the float stage, the charger supplies a voltage that just counterbalances the battery internal voltage, with a bit extra to compensate for internal self-discharge. It can remain in that stage for months if necessary. Usually about 13.4V to 13.6V.

So you can see that in the first stage there is nothing to stop the full output amps going into the battery, and maybe that is when some damage is happening. It's only a guess, of course, but as others have said, gels should last for many years if they are treated properly, so something must be wrong somewhere if they only last 18 months.

Note that charging amps that are too high from the alternator is an unusual problem, very few B2B chargers push out more than about 60A, and those that do are usually specially installed for that purpose, so the users know what they are doing. I'm not very familiar with this CTEK setup, so I don't know if the amps can be dialled down if it's too high.

You could actually measure the amps with a clamp meter quite easily, to see if that's what is happening. Probably your lad who services wheelchairs has access to a suitable one.

 

[TheLifeofBrian]

I'm still trying to find the cause.....
Could it just be I've taken too much power out of them? I don't really see how, even if I had the satellite & TV on, plus stereo & various chargers for several hours I don't think that would have been more than 15 amps, so even for 5 hours that's only 75 amps (or has my maths failed after 40+ years since school ) & there are 2 x 110 ah batteries!! Couple that with overcast weather so not much solar power....
I think I'll speak to the battery supplier tomorrow (alpha batteries) & see what they suggest. We're booked into Malvern in 2 weeks so need to get it sorted asap!
Also I'll try testing them individually & see what the results are

If they have died & get replaced I might sell them & bite the bullet & get a lithium - partly to save weight!

Thank you all for your help - excellent Funster advice as usual

 

[TheLifeofBrian]

By the way if you're at Lincoln we're the van in the dark up the corner

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