Batteries not charging as expected

[magnetman]

If the cells have indivdual caps you could get a refractometer and check the acid. I did this when Rolls batteries were causing problems and it turned out one of the cells was virtually water with an SG below 1.1. They want to be about 1.26.

 

I did get them replaced under warranty as I was the original purchaser and they only lasted 18 months.

 

Refractometers are incredibly cool.

Edited February 23, 2023 by magnetman

[Tony Brooks]

11 minutes ago, magnetman said:

If the cells have indivdual caps you could get a refractometer and check the acid. I did this when Rolls batteries were causing problems and it turned out one of the cells was virtually water with an SG below 1.1. They want to be about 1.26.

 

I did get them replaced under warranty as I was the original purchaser and they only lasted 18 months.

 

Refractometers are incredibly cool.

So are battery hydrometers, which do the same job, but in my view less risk of getting acid on your cloths.

[magnetman]

1 minute ago, Tony Brooks said:

So are battery hydrometers, which do the same job, but in my view less risk of getting acid on your cloths.

Good point. I just thought looking through a telescope thing and thinking how it worked was good fun.

 

But yes I suppose a hydrometer, while being a little boring, is probably better in a lot of ways.

[Tony Brooks]

1 minute ago, magnetman said:

Good point. I just thought looking through a telescope thing and thinking how it worked was good fun.

 

But yes I suppose a hydrometer, while being a little boring, is probably better in a lot of ways.

 

However, you need less acid for a refractometer, which could be useful for a battery with a shorting cell that is getting dry.

Edited February 23, 2023 by Tony Brooks

[magnetman]

1 minute ago, Tony Brooks said:

 

However, you need less acid for a refractometer, which could be useful for a battery with a shorting cell that is getting dry.

 

But how would you reach the acid? The plates will be in the way.

Actually the pipettes are quite thin at the ends so maybe they can reach between the plates.

[Tony Brooks]

1 minute ago, magnetman said:

 

But how would you reach the acid? The plates will be in the way.

Actually the pipettes are quite thin at the ends so maybe they can reach between the plates.

 

I used to push a ball point ink tube into the hydrometer hose. The separators usually have ribs on them and the tube (and I suspect a pipette) fits between the flat part of the separator and plate. If the cell is that dry and others are not, it is pretty sure the cell is shorting.

[ditchcrawler]

55 minutes ago, Tony Brooks said:

 

I used to push a ball point ink tube into the hydrometer hose. The separators usually have ribs on them and the tube (and I suspect a pipette) fits between the flat part of the separator and plate. If the cell is that dry and others are not, it is pretty sure the cell is shorting.

Its definitely not well, I probably wouldn't bother checking past that discovery.

[DShK]

1 hour ago, Tony Brooks said:

It will if you have the money, but I suspect a length of cable, blue connector and a 13A wander socket would be cheaper. The shore bollard should have a MCB & RCD for protection.

Ah, that's good to know! I wasn't sure if I needed a seperate RCD/MCB on board, earthing etc confuses me a bit still so wasn't sure - better safe than sorry tbh!

 

I'll purchase a hydrometer and use it to test my batteries as well. Seems a god thing to have either way.

[Tony Brooks]

As long as you use the lead like an extension lead and do not plug it into any boat system, then there will be no earthing issues.

 

A battery hydrometer is unlikely to show any decimal points or places, so put a decimal point after the first 1 on the float number, then post each cell reading here, so we can advise.

[magnetman]

6 minutes ago, DShK said:

 

I'll purchase a hydrometer and use it to test my batteries as well. Seems a god thing to have either way.

 

True messiahs have refractometers. It is only the pretenders who use hydrometers.

 

 

[Tony Brooks]

Just now, magnetman said:

 

True messiahs have refractometers. It is only the pretenders who use hydrometers.

 

 

I suspect a refractometer is more accurate because there is no meniscus to confuse the reading, as there is in a hydrometer, but I suspect a battery hydrometer is cheaper and more readily available locally.

[DShK]

Refractometer isn't that expensive, £19 vs £7 for a hydrometer. Assuming this looks like it'll do the job I'll get one:

 

https://www.amazon.co.uk/Antifreeze-Refractometer-Checking-Automobile-Propylene/dp/B08PNJTPDV/ref=sr_1_1_sspa?crid=3ADMDL6F646MS&keywords=battery%2Brefractometer&qid=1677155363&sprefix=battery%2Brefractometer%2Caps%2C89&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&smid=A383NGSFO64TLP&th=1

 

 

[magnetman]

That is what I used although not from Amazon. Looks alright.

19 minutes ago, DShK said:

 Seems a god thing to have either way.

 

[ditchcrawler]

52 minutes ago, Tony Brooks said:

I suspect a refractometer is more accurate because there is no meniscus to confuse the reading, as there is in a hydrometer, but I suspect a battery hydrometer is cheaper and more readily available locally.

I found them much easier to read when I was at work but I don't own one myself.

[Tony Brooks]

45 minutes ago, magnetman said:

That is what I used although not from Amazon. Looks alright.

 

 

I would just point out that the link DShK posted has a caveat saying "🚗【Note】— Do not measure abrasive or corrosive chemicals with this instrument."  Yet they put in larger characters "Refractor for battery acid".

 

I don't know which is correct, but it might suffer from the acid.

[Bee]

When my batteries developed charging issues and I couldn't work it out I used to take them to the local tyre and batt. place and they would stick that sort of toaster thingy on them and do that drop test thing that us non electrical folk sort of understand.

[Tony Brooks]

35 minutes ago, Bee said:

When my batteries developed charging issues and I couldn't work it out I used to take them to the local tyre and batt. place and they would stick that sort of toaster thingy on them and do that drop test thing that us non electrical folk sort of understand.

 

Yes, that is fine as long as it is matched to battery capacity and the batteries are fairly well charged, If not then the result may not be misleading. Drop test a battery on a car that won't start on a cold morning and it will almost certainly show up as faulty. Give it a good charge and it is likely to test differently.

[magnetman]

The other thing is to use a conductance tester. I used to have one of the original Motorola moving coil battery conductance testers. It was a device originally patented by Motorola. Modern types are digital display but you can't beat a needle for the real thing.

 

The test the battery regardless of charge level ie not voltage dependent. 

Useful item I gave it away as now have Lithium Titanate and LFP batteries doing all the jobs on the boats. 

 

no acid. 

Edited February 23, 2023 by magnetman

[DShK]

4 hours ago, Tony Brooks said:

 

I would just point out that the link DShK posted has a caveat saying "🚗【Note】— Do not measure abrasive or corrosive chemicals with this instrument."  Yet they put in larger characters "Refractor for battery acid".

 

I don't know which is correct, but it might suffer from the acid.

Yeah, typical poorly translated from chinese amazon description methinks. Fingers crossed it works fine. Amazon are usually pretty good about returns if it fails immediately.

 

1 hour ago, magnetman said:

The other thing is to use a conductance tester. I used to have one of the original Motorola moving coil battery conductance testers. It was a device originally patented by Motorola. Modern types are digital display but you can't beat a needle for the real thing.

 

The test the battery regardless of charge level ie not voltage dependent. 

Useful item I gave it away as now have Lithium Titanate and LFP batteries doing all the jobs on the boats. 

 

no acid. 

 

Hmm those look quite expensive. I am seriously considering going lithium in the future, so it might not be worth the investment....

[ditchcrawler]

1 hour ago, Tony Brooks said:

 

Yes, that is fine as long as it is matched to battery capacity and the batteries are fairly well charged, If not then the result may not be misleading. Drop test a battery on a car that won't start on a cold morning and it will almost certainly show up as faulty. Give it a good charge and it is likely to test differently.

Some breakdown companies love them "just happen to have a new battery on the van Sir"

[magnetman]

I was quite schocked by the prices. I got the one I had (Motorola analogue type later called Midtronics) on fleabay for about £2O. It might be in one of the boats somewhere but I think I gave it away. 

Refractometer will tell you if you have dead cells in the battery blocks. 

Edited February 23, 2023 by magnetman

[cuthound]

On 23/02/2023 at 10:46, Tony Brooks said:

So are battery hydrometers, which do the same job, but in my view less risk of getting acid on your cloths.

 

Both need the readings correcting for temperature for complete accuracy, but if looking for one dodgy cell it isn't necessary.

[MtB]

On 23/02/2023 at 12:31, DShK said:

efractometer isn't that expensive, £19 vs £7 for a hydrometer.

 

You're not taking into account the fact that you'll need to buy a new set of clothing a 10 days after using one. 

 

If you close the lid on the sample slightly too clumsily and quickly, they spray out the finest imaginable spray of acid droplets onto whatever you are wearing and after a week or two, each droplet will have eaten itself a 3mm diameter hole. 

 

DAMHIK. 

 

 

[dmr]

Refractometers are lovely engineered devizes, whilst hydrometers are nasty ugly cheap things. However for most measurements hydrometers are probably the better option, and you can stir up the acid a bit with them before you do the measurement, good if you have recently topped up the batteries or suspect a bit of stratification etc.

The dial type hydromeers are quicker and easier to use than the float type, though possibly less accurate.

The answer is to have a hydrometer for normal use, and a refractometer to be kept on the shelf and admired, knowing that its ready and waiting if you ever get an urge to check the calibration of the hydrometer.

 

[rusty69]

5 minutes ago, dmr said:

The answer is to have a hydrometer for normal use, and a refractometer to be kept on the shelf and admired, knowing that its ready and waiting if you ever get an urge to check the calibration of the hydrometer.

The answer is to use battery technology that wasn't invented in 1859.