Topping up "sealed" batteries

[Ric]

I have a 70Ah sealed lead-acid battery. The charge indicator is clear, which according to the manufacturer, means that it needs replacing.

However, having beasted it on a test rig this afternoon, along with its siblings acquired at the same time, there is still plenty of useful life in it. It provided 10A continuously for 120mins before it dropped below 12.2v, whereas its siblings (who showed green dots on the charge indicator) all gave up after about 30 mins.

The battery without the green dot is clearly the best of the bunch, so can I top up the electrolyte and use it a bit longer?

 

[maby]

I have a 70Ah sealed lead-acid battery. The charge indicator is clear, which according to the manufacturer, means that it needs replacing.

However, having beasted it on a test rig this afternoon, along with its siblings acquired at the same time, there is still plenty of useful life in it. It provided 10A continuously for 120mins before it dropped below 12.2v, whereas its siblings (who showed green dots on the charge indicator) all gave up after about 30 mins.

The battery without the green dot is clearly the best of the bunch, so can I top up the electrolyte and use it a bit longer?

I see no reason why not - just drill a hole very gingerly, top it up, then plug the hole!

 

[coromar]

Hi,
I had an Ecosol sealed battery that showed a clear indicator. I was told by the supplier to hit it as the indicator sometimes get stuck.

I bumped it and hey-presto the indicator appeared.

All has been ok for the next 2 years.

 

[VicMallows]

I've had new batteries where the indicator doesn't show ...just a gimmick if you ask me.

Vic

 

[Plevier]

Have you tried peeling off any labels on top? Often there is a cover strip under the label that you can lever out. Depends what make it is.

 

[Barry Jones]

When sealed batteries die, its not usually due to a lack of electrolyte.
I would advise that you don't use the magic eye as an accurate indicator, but continue to load test them as you are doing.

Your battery is not in the prime of health and has lost nearly half its original capacity, but it sounds like its still useable.

I have a 70Ah sealed lead-acid battery. The charge indicator is clear, which according to the manufacturer, means that it needs replacing.

However, having beasted it on a test rig this afternoon, along with its siblings acquired at the same time, there is still plenty of useful life in it. It provided 10A continuously for 120mins before it dropped below 12.2v, whereas its siblings (who showed green dots on the charge indicator) all gave up after about 30 mins.

The battery without the green dot is clearly the best of the bunch, so can I top up the electrolyte and use it a bit longer?

 

[pvb]

I have a 70Ah sealed lead-acid battery. The charge indicator is clear, which according to the manufacturer, means that it needs replacing.

The "magic eye" indicator on maintenance-free batteries isn't necessarily a good gauge of electrolyte level. These batteries have a healthy reserve of electrolyte, to allow for some loss in use. Some years ago, I removed the magic eye from a battery which, like yours, was showing no indication. I found that the electrolyte level was still about 1cm above the plates. The battery went on to give several years' service.

 

[PeterGibbs]

I have a 70Ah sealed lead-acid battery. The charge indicator is clear, which according to the manufacturer, means that it needs replacing.

However, having beasted it on a test rig this afternoon, along with its siblings acquired at the same time, there is still plenty of useful life in it. It provided 10A continuously for 120mins before it dropped below 12.2v, whereas its siblings (who showed green dots on the charge indicator) all gave up after about 30 mins.

The battery without the green dot is clearly the best of the bunch, so can I top up the electrolyte and use it a bit longer?

On an electrics course the very experienced instructor told us - sealed batteries are just regular gear with another half inch of fluid on top: why buy them? Quite.

I would squeeze the last bit of life out of yours before I dumped it - whatever the magic eye says. Just like the rest of us with open top batteries.........!

PWG

 

[Roberto]

On an electrics course the very experienced instructor told us - sealed batteries are just regular gear with another half inch of fluid on top: why buy them? Quite.

In some countries (I don't know about the UK), if you have open cell batteries they must be fitted in a closed container/box which is vented to the outside of the cabin, sometimes it is feasible sometimes not...
I'd prefer open cell batteries but simply have not the space for a closed container, so sealed batteries they are