Battery at end of life?

[Bod]

Flooded lead acid starter battery, appears to be discharging faster than normal.  Monitored by a Smart gauge.

The batteries, both starter and domestic are linked and charged by solar only during the winter, this has given no problems for the last 6-8 years.

Recently the smart gauge has been showing a decrease in percentage of charge.  Not rising in the sunshine, not that we've had much!

Start battery is at least 15 years old, and could be much older. Domestics are 12 years old, semi tractions.

I've disconnected the starter battery completely, the voltage after being disconnected for 1 hour was 12.08 and falling.  No point in testing the domestics as the solar was charging them well.

Hydrometer readings for the start battery put 5 of the cells in the green (well charged) the 6th next to the - terminal, didnt rise at all, fully in the "flat" red area.

Is there any point in separately mains charging this battery, or just replace it?

Next question.

The domestic batteries are 6 volt arranged in series and parallel to give 12 volts.  To remove the start battery, at least two of the domestic batteries will have to be removed for space, or the exhaust silencer moved!

These 4 batteries have never been disturbed since fitting.

When replacing the two removed to make space to get the start out, should they be replaced as was, or would there be advantage in shuffling the 4 around?

2431, instead of the original 1234.

Thanks

Bod

[ditchcrawler]

I just bought a new starter battery from Halfords 

485286

Yuasa YBX3664 HD SMF Bat

1

£100.00

[nicknorman]

18 minutes ago, Bod said:

Flooded lead acid starter battery, appears to be discharging faster than normal.  Monitored by a Smart gauge.

The batteries, both starter and domestic are linked and charged by solar only during the winter, this has given no problems for the last 6-8 years.

Recently the smart gauge has been showing a decrease in percentage of charge.  Not rising in the sunshine, not that we've had much!

Start battery is at least 15 years old, and could be much older. Domestics are 12 years old, semi tractions.

I've disconnected the starter battery completely, the voltage after being disconnected for 1 hour was 12.08 and falling.  No point in testing the domestics as the solar was charging them well.

Hydrometer readings for the start battery put 5 of the cells in the green (well charged) the 6th next to the - terminal, didnt rise at all, fully in the "flat" red area.

Is there any point in separately mains charging this battery, or just replace it?

Next question.

The domestic batteries are 6 volt arranged in series and parallel to give 12 volts.  To remove the start battery, at least two of the domestic batteries will have to be removed for space, or the exhaust silencer moved!

These 4 batteries have never been disturbed since fitting.

When replacing the two removed to make space to get the start out, should they be replaced as was, or would there be advantage in shuffling the 4 around?

2431, instead of the original 1234.

Thanks

Bod

New starter battery required! I don’t think there is any point in rearranging the batteries.

[Tony Brooks]

The 6th cell probably has a short circuit, so a Brian implied, replace it.

 

I would not expect the start battery to be monitored by the Smartguage, it is usually used for the domestic bank.

 

As batteries sulphate, they take less and less time to fully charge and also discharge. The battery ends are also likely to bow outwards.

 

As batteries start internally shorting, they take longer and longer to fully charge and less and less time to discharge to a given point. They also tend to get one cell hotter than the rest or gassing more whilst charging and needing far more topping p than the others. This may help you decide if the old batteries are worth keeping.

 

At 12 years old the domestics must be getting towards the end of life and a sulphation causes the negative plates to swell and push against the internal separators a cell or cells may be on the verge of shorting, so moving them about may hasten a short, but you won't know if it happens until you try it. 

 

[Bod]

Smart gauge, has 2 volt meters built in, one for the main battery(ies) which is connected to the SOC display, the other just gives the voltage of the secondary battery only.

I'm inclined to replace the start battery, as there is clearly a fault in one cell.

It's wether it's worth shuffling the leisure batteries around. I don't know.

The last set of leisure batteries, had had a life on a cherry picker, before the boat, where they lasted at least 5 years, before I replaced them like for like type wise, as the original make and model hadn't been made for nine years.  I'm hoping for a few more years from this set.

 

Bod

Edited November 25, 2025 by Bod
add comment

[Tony Brooks]

1 hour ago, Bod said:

Smart gauge, has 2 volt meters built in, one for the main battery(ies) which is connected to the SOC display, the other just gives the voltage of the secondary battery only.

 

I know, but what I don't know is which bank you consider main and which secondary. far more explicit to use starting/engine and domestic/house.

 

1 hour ago, Bod said:

The last set of leisure batteries, had had a life on a cherry picker, before the boat, where they lasted at least 5 years, before I replaced them like for like type wise, as the original make and model hadn't been made for nine years.  I'm hoping for a few more years from this set.

 

As I said, suck it and see. You would have to be unlucky to have moving them about cause a sort, but it could happen. If they cost getting on for "ouch" then they may well be pocketed plates, so would much better resist short-circuiting cells.

[cuthound]

5 hours ago, ditchcrawler said:

I just bought a new starter battery from Halfords 

485286

Yuasa YBX3664 HD SMF Bat

1

£100.00

 

Didn't they ask you for a car registration number and look completely baffled when you said it is for a boat?

 

[ditchcrawler]

27 minutes ago, cuthound said:

 

Didn't they ask you for a car registration number and look completely baffled when you said it is for a boat?

 

I ordered it on line to pick up in the shop, It took them 5 days to get it

[MtB]

Curiously I bought a 110Ah battery from Tayna who get so many recs on here. 

 

It arrived about ten minutes before I actually placed my order. *

 

 

 

* Exaggerating slightly. Arrived about 18 hours after ordering. 

 

 

 

 

 

Edited November 25, 2025 by MtB

[ditchcrawler]

10 hours ago, MtB said:

Curiously I bought a 110Ah battery from Tayna who get so many recs on here. 

 

It arrived about ten minutes before I actually placed my order. *

 

 

 

* Exaggerating slightly. Arrived about 18 hours after ordering. 

 

 

 

 

 

Mine should have been next working day which was more convenient that delivery, but it didn't

[Peanut]

They do say, measure twice, cut once, which is a very good idea. If you order three batteries, and they don't quite fit the battery box, and weigh over 25 Kg each, then it might be cheaper to drive across the country to Wales to change them, rather than paying postage to return them, and again to deliver the replacements. That is, if you can even get a carrier willing to take them. 🤭

[Ronaldo47]

On 25/11/2025 at 19:56, cuthound said:

 

Didn't they ask you for a car registration number and look completely baffled when you said it is for a boat?

 

 A few years ago I had the car registration requirement  experience with Halfords when  unsuccessfully  trying to buy an uncommon type of  battery, specifically designed for a type of sit-on lawn mower that was not legal for use on the public highway and so would never have a licence plate. It was on their web site, but impossible to proceed to order or check in-store availablity without entering  a vehicle licence plate number. I eventually found the telephone number of a customer services person who was able to access their computer without needing a vehicle  registration number and confirm that my local branch had them in stock.

Edited November 28, 2025 by Ronaldo47
Typos

[Jon57]

On the subject of end of life of batteries. A friend has just replaced his leisure batteries (sealed) with new like for like. When he took the old ones to the scrapyard he was told they were not worth as proper lead acid batteries. It's been a while since I've scraped any.  Can anyone shed any light on this as I've 4 agm 99% pure lead acid batteries to get rid of shortly. TIA. 

[Tony Brooks]

14 minutes ago, Jon57 said:

On the subject of end of life of batteries. A friend has just replaced his leisure batteries (sealed) with new like for like. When he took the old ones to the scrapyard he was told they were not worth as proper lead acid batteries. It's been a while since I've scraped any.  Can anyone shed any light on this as I've 4 agm 99% pure lead acid batteries to get rid of shortly. TIA. 

 

 

From Google AI, so needs confirming if interested enough:

 

The proportion of alloys in lead-acid battery plates varies, but a common composition includes a small percentage of calcium and tin, with other elements like silver, barium, or aluminum added for improved performance. For example, an alloy might contain about 0.02-0.05% calcium, 0.3-0.5% tin, and 0.02-0.05% silver, with the rest being lead. Other variations exist, such as a lead-calcium-tin-aluminum alloy, with the specific amounts adjusted to balance characteristics like corrosion resistance, mechanical strength, and cost. 

 

 

Common alloy compositions

 

• Lead-calcium-tin: A basic alloy for positive grids, often consisting of about 0.02–0.05% calcium, 0.3–0.5% tin, and the balance lead.
• Lead-calcium-tin-silver: Another common composition includes a small amount of silver for improved mechanical properties, such as 0.06–0.08% calcium, 0.3–0.6% tin, 0.01–0.04% silver, and the rest lead.
• Lead-calcium-tin-aluminum-barium: More complex alloys use additional elements to enhance strength and corrosion resistance. One example includes 0.05–0.07% calcium, 0.09–1.3% tin, 0.006–0.010% silver, 0.015–0.025% aluminum, 0.0100–0.0170% barium, and the balance lead. 

 

This does not contain reference to the alloy percentage for lead-antinomy plates, but taking lead-calcium as an example you can see the 99% pure lead claim for the plate is in the right ballpark, but there is still the case, separators, possible plate pockets, and electrolyte to take into account, so that 99% is really a marketing fiction. 

 

I suspect the price of lead was at a low point when he took them and that was the way the operative decided to justify the price, or they did not want them. It could be the scrapie was pulling a fast one, but I would not like to say that based on the information given.

[GUMPY]

All a scrappy will do is reduce the price per kg paid, unless it's a scam. Most have a minimum of £10 pay out  and if the weight is not enough then tough.

Just scrapped 4 starter batteries Inc 2 x AGM, price was rubbish I got £11 for the four.

[Jon57]

I've made some enquiries at my local scrap yard. The yard guy mentioned about a battery having more than two terminal post? That maybe the way he identified the difference in a crude sort of way. Mine only have the screw in battery posts so will remove them and all labels and see what happens when the time comes 

£200 a ton atm 

[Tony Brooks]

4 minutes ago, GUMPY said:

All a scrappy will do is reduce the price per kg paid, unless it's a scam. Most have a minimum of £10 pay out  and if the weight is not enough then tough.

Just scrapped 4 starter batteries Inc 2 x AGM, price was rubbish I got £11 for the four.

 

Which suggests that the lead price is low at the moment, compared with the £5 per battery people were quoting a while back.

[Jon57]

2 minutes ago, Tony Brooks said:

 

Which suggests that the lead price is low at the moment, compared with the £5 per battery people were quoting a while back.

Good job it's black Friday. 20% off fogstar batteries is looking like a no brainier. 👍

[Alan de Enfield]

3 minutes ago, Tony Brooks said:

 

Which suggests that the lead price is low at the moment, compared with the £5 per battery people were quoting a while back.

 

A couple of years ago I got £10 each for 100Ah and £20 for 230Ah batteries (and that was the 'collected' price')

[Jon57]

6 minutes ago, Alan de Enfield said:

 

A couple of years ago I got £10 each for 100Ah and £20 for 230Ah batteries (and that was the 'collected' price')

He got £18 for 4 110amp batteries. Better to use as ballast or a mud weight. 😢

[Tony Brooks]

3 minutes ago, Jon57 said:

He got £18 for 4 110amp batteries. Better to use as ballast or a mud weight. 😢

 

So allowing for price fluctuations, that is roughly in line with the £5 a battery I mentioned.

[Jon57]

2 minutes ago, Tony Brooks said:

 

So allowing for price fluctuations, that is roughly in line with the £5 a battery I mentioned.

Which make getting lithium a bit more of a no brainier if you need to replace 4x agm batteries. Even with the additional expense of the correct charging and monitoring if you need to upgrade. Fogstar 280amp drift pro gen 2 is now available at £560 . How much would 4 agm 110 batteries be. The difference is getting stupid not to go down that route I'm thinking. 

[Tony Brooks]

1 minute ago, Jon57 said:

Which make getting lithium a bit more of a no brainier if you need to replace 4x agm batteries. Even with the additional expense of the correct charging and monitoring if you need to upgrade. Fogstar 280amp drift pro gen 2 is now available at £560 . How much would 4 agm 110 batteries be. The difference is getting stupid not to go down that route I'm thinking. 

 

I agree, but 4 x 110 Ah open cell batteries will start at about £360 upwards, so taking the cost of the extra kit needed for a competent LFP install, LA may still make sense for some.

[Jon57]

1 minute ago, Tony Brooks said:

 

I agree, but 4 x 110 Ah open cell batteries will start at about £360 upwards, so taking the cost of the extra kit needed for a competent LFP install, LA may still make sense for some.

Agree. It's all to be taken into account. But even if you don't have most of the equipment all ready installed the price is secondary to the advantages of lithium even with the ongoing investigation on the gayton day boat in my opinion. 

[ditchcrawler]

1 hour ago, GUMPY said:

All a scrappy will do is reduce the price per kg paid, unless it's a scam. Most have a minimum of £10 pay out  and if the weight is not enough then tough.

Just scrapped 4 starter batteries Inc 2 x AGM, price was rubbish I got £11 for the four.

AI answer

The price for a scrap car battery in the Lowestoft area will depend on weight and type, with lead-acid batteries typically fetching around £0.45-£0.65 per kg or £4.50-£6.50 per unit. To get the most accurate price and find local buyers, you will need to contact local scrap merchants or use online comparison tools like Scrappie.