What is the life of gel batteries? (11 Viewers)

[headlight]

I'm having trouble following you as well?
How have I drained my batteries too quickly - unless you are referring to trying an inverter which turned on and instantly off and I am not doing anything to charge the batteries other than using the CTEK equipment as it was designed and professionally installed?
I am asking them for their opinion on the fact that it has been suggested to me that they can output too much current for the job they are designed for and could therefore have overcharged my batteries.

What I am saying is that you are the user therefore it is up to you to ensure that what you are doing is within the battery recommended specs.
Any problems caused by not staying within the specs of the battery are down to you.
I am sure that is what CTEK will say.
CTEK made the charger, they can't be held responsible as to how you have used it.

 

[ChrisL]

Autorouter has basically said this twice:

Your batteries should be charged at no more than 40a for the pair (20a each).

Your setup has been charging them at 100a.

QED.

I have to say I don't understand this, I was under the impression that the rate a lead acid battery charges at is defined by its internal resistance, which is why the current reduces as the internal resistance increases as it becomes more charged, are you saying it's possible to push more amps into a battery then its internal resistance would allow? My B2B can provide a 30 amp charge but when I had gel batteries if they were only a little discharged it would only provide 8 amps and I never saw more then 18 amps when they were down to 50%.

 

[headlight]

TheLifeofBrian I've just re read this thread and this is the second set of batteries you've goosed ?

 

[Hedgewitch]

This might be apples & oranges, but I have a small gel battery in a ride-on lawnmower; the mower is used a couple of times a year to cut a meadow and the rest of the year has a tow hitch and drags a small trailer around.

It lives in a non-insulated shed hooked up to a Ctek unit when not in use.

Both the battery and Ctek are at least ten years old . . . (and the only occasion the engine did not start first time was because we'd missed an annual service and it needed some TLC).

 

[TheLifeofBrian]

I have to say I don't understand this, I was under the impression that the rate a lead acid battery charges at is defined by its internal resistance, which is why the current reduces as the internal resistance increases as it becomes more charged, are you saying it's possible to push more amps into a battery then its internal resistance would allow? My B2B can provide a 30 amp charge but when I had gel batteries if they were only a little discharged it would only provide 8 amps and I never saw more then 18 amps when they were down to 50%.

I have to say that's exactly how I understood it

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[TheLifeofBrian]

TheLifeofBrian I've just re read this thread and this is the second set of batteries you've goosed ?

Yes I obviously bugger my batteries up on purpose and only £400 a time!

 

[SpeedyDux]

I had a gel hab battery that needed replacing. It was only 15 years old!

 

[Richard n Ann]

I have to say that's exactly how I understood it

When the batteries are discharged they will take whatever the charger is rated at. The internal resistance only comes up as they charge

 

[headlight]

Yes I obviously bugger my batteries up on purpose and only £400 a time!

So what you're saying is that if you get done for doing 100mph it's not your fault it's the car manufacturers fault for making and selling a car capable of breaking the speed limit.

 

[Richard n Ann]

So what you're saying is that if you get done for doing 100mph it's not your fault it's the car manufacturers fault for making and selling a car capable of breaking the speed limit.

Not quite, he didn't know he was doing 100mph

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[TheLifeofBrian]

So what you're saying is that if you get done for doing 100mph it's not your fault it's the car manufacturers fault for making and selling a car capable of breaking the speed limit.

I think we may be talking at cross purposes here.
How am I able to alter how much charge the CTEK units are putting into my batteries? And how am I responsible for them doing that?

 

[headlight]

I think we may be talking at cross purposes here.
How am I able to alter how much charge the CTEK units are putting into my batteries? And how am I responsible for them doing that?

You can't alter how the charger works but the onus is on you to ensure that the charger is suitable for your needs.
If it is not then it is your problem not the charger manufacturers problem and you have to suck up the result.
I cant see you getting anywhere with CTEK.
I suppose you could try the "professional " who fitted the charger ?

 

[Hedgewitch]

How am I able to alter how much charge the CTEK units are putting into my batteries? And how am I responsible for them doing that?

Did you set the 'mode' on your Ctek unit to AGM?

 

[AdrianChen]

I have to say I don't understand this, I was under the impression that the rate a lead acid battery charges at is defined by its internal resistance, which is why the current reduces as the internal resistance increases as it becomes more charged, are you saying it's possible to push more amps into a battery then its internal resistance would allow? My B2B can provide a 30 amp charge but when I had gel batteries if they were only a little discharged it would only provide 8 amps and I never saw more then 18 amps when they were down to 50%.

A wet lead acid battery if re-charged at a high voltage/current will start to produce heat during the process, sufficient to induce gassing and reduce the electrolyte level within the battery, so in the past many batteries relied on being topped up with water to cover the plates again as they depleted. The higher the voltage and current, the more gassing takes place and the more they needed topping up.

Commonly now leisure batteries are sealed/vented and do not require topping up, but in reality they are just made with higher electrolyte fill from new to allow for depletion, and failure often arises because the electrolyte becomes stronger as the water element is gassed off.

When Gel batteries are subjected to the same situation of being charged at high voltage/current the electrolyte, being a gel can't gas off in the same way, and can't be topped up, so they need to be kept within their specification or they will get damaged. Different manufacturers may use different Gels - I don't know, but the Victron/Sonnechein/Exide ones in my experience (Limited and out of date now!) were very reliable.

So a battery will accept a given charge current in proportion to the voltage being supplied - the higher the voltage the higher the acceptance rate, but at some point that will be sufficiently high to produce sufficient heat to "boil" or "Fizz" the electrolyte, or even buckle the plates. In selecting a charger the rule used to be for around the charger to be a max of around 15% of the batteries AH capacity, 15amp for a 100amp battery. A "smart" charger (as AutoRouter has explained) may start it's programme by increasing its output voltage to a level where the batteries are accepting the chargers maximum output current. If this is 15amps the 100amp battery should cope, however if the charger can increase the voltage sufficiently the battery may accept far more, and the possibility exists for that level to damage a battery not designed for it.

One of the benefits with Lithium is the charge rate, because they can manage a very high charge current compared to LA, especially compared to cheap leisure batteries, and even purpose made deep cycle wet lead acid batteries such as the Trojan T105. Gels benefit is that they don't need any maintenance, gas very little if at all and can cope with deep cycles and PSOC storage better than most other LA types, but their downside is they are comparatively slow to recharge, and are not the best choice for high current loads, but they do work well as leisure batteries......