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moiuk

Wet batteries left dry.

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hi,

 

The batteries I have just taken ownership of seem not to have been maintained very well.  I have topped them up with water now, but it needed 2 litres of distilled water across 4 batteries...

 

One of the worst was the photo attached. Anybody know how badly damaged this is from looking at it alone?   The batteries as a whole seem to be functioning OK, but not brilliant. Should I be concerned, or just let it run  until they stop being able to hold  charge?

20200731_142449_exported_5338119765334035256.jpg

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They’re almost certainly now ex-batteries. Do you have any way of measuring their capacity? Amphour counter?
 

 

Edited by WotEver
Typi

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They will not be performing very well, you are going to have to buy new batteries in the near future, but maybe take the next 6 or 8 weeks as a 'learning curve' and get to understand how long you have to charge the batteries (every day), then when you have learned, buy some new ones and look after them.

 

You can 'kill' batteries in a as little as a couple of weeks if you do not care for them properly.

 

Do you have any battery monitoring systems on the boat ?

How are you planning to charge the batteries ? (are you in a marina, cruising, or have a generator ?)

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12 minutes ago, Alan de Enfield said:

They will not be performing very well, you are going to have to buy new batteries in the near future, but maybe take the next 6 or 8 weeks as a 'learning curve' and get to understand how long you have to charge the batteries (every day), then when you have learned, buy some new ones and look after them.

 

You can 'kill' batteries in a as little as a couple of weeks if you do not care for them properly.

 

Do you have any battery monitoring systems on the boat ?

How are you planning to charge the batteries ? (are you in a marina, cruising, or have a generator ?)

I actually have a lithium setup that I am moving across from my previous boat so the long term will be fine. But in the short term (5 weeks) until I get the all installed professionally I have to make do with these.  Fully charged I get a stable 12.7 volts, which drop down to around 12 volts overnight with just the fridge and freezer and some lights etc.  Originally these are 4 x trojan 6v 220ah batteries, so there should be 440aH there. Clearly not any more....

 

The only battery monitor at the moment is a basic volt meter display.

 

I will be continuously crusing and never plugged into mains. Charging will be by solar, and engine in summer and topped up by Honda eu20i generator in the dark months.

Edited by moiuk

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Look like Trojans. The dry bits are likely dead but any plate left in acid might well be ok. Carefully fill them up and report back on how much water went into each cell. Trojans can take a lot of abuse and still recover but these have been neglected,  we don't know how long since they had a full charge, might be possible to recover them to some extent. And worth a bit of money at the scrap yard.

 

...................Dave

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35 minutes ago, dmr said:

Look like Trojans. The dry bits are likely dead but any plate left in acid might well be ok. Carefully fill them up and report back on how much water went into each cell. Trojans can take a lot of abuse and still recover but these have been neglected,  we don't know how long since they had a full charge, might be possible to recover them to some extent. And worth a bit of money at the scrap yard.

 

...................Dave

I used 2 litres to fill them all up across the 4 batteries. Most cells looked like they had enough to just cover the plates.

 

My understanding  is that 5hese are possibly 6 years old, but never actually used as always plugged into mains at a marina. Also means never actually topped up either my guess..

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You have lost a lot of their capacity, but my guess is that the capacity remaining will be reasonably stable over the next couple of months.  From the voltages, you are using most of that ‘capacity’ overnight, so if you can recharge every day you should with care survive until you get your lithium set up working.  Failing that, you could replace the existing bats with a couple of really cheap 110Ah bats which should be enough to keep you going overnight with care for a few weeks.

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9 hours ago, moiuk said:

I will be continuously crusing and never plugged into mains. Charging will be by solar, and engine in summer and topped up by Honda eu20i generator in the dark months.

 

Not via the "12v" output I trust. he 12V output is unregulated so could damage batteries and has  a very low output. Use it to power a mains battery charger

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8 hours ago, moiuk said:

I used 2 litres to fill them all up across the 4 batteries. Most cells looked like they had enough to just cover the plates.

 

My understanding  is that 5hese are possibly 6 years old, but never actually used as always plugged into mains at a marina. Also means never actually topped up either my guess..

Presuming they are Trojans (and they look like it) 2 litres into 4 batteries isn’t a huge amount. Did you top them up to the correct level which is 3mm below the bottom of the filling well!? However, the level rises when the cells are fully charged so if the batteries aren’t fully charged, add just enough water to cover the plates, then fully charge, then top up to the 3mm below bottom of well mark

 

These batteries do use water and it needs checking every few months (depending on usage) but they are very good batteries. Mine are 6 years old (extensive leisure use) and still have their original capacity.

 

They do also like a fairly high finishing voltage (end of charge) at around 14.8v. Your cells May have become sulphated from not being charged properly, but a prolonged equalisation charge at 15.5v will recover some or all of it. If you fully charge the batteries and check the specific gravity with a hydrometer or refractometer, you should get 1.277 and anything below 1.250 means they need an equalise charge.

Edited by nicknorman

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26 minutes ago, Tony Brooks said:

 

Not via the "12v" output I trust. he 12V output is unregulated so could damage batteries and has  a very low output. Use it to power a mains battery charger

I am plugging it into the combi invertor/charger via the 13amp socket, which should give me an 80amp charge on bulk mode.

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You may find they're ok. Our shared boat has four Trojan-a-like batteries which are 10 years old. They were chronically undercharged for a lot of that time. Since fitting solar and keeping them topped up they seem to have recovered to an extent, usual daytime charge voltage about 28.6 v and they stay over 25.4 v overnight running the fridge, inverter and odds and ends. I regularly put in a L or more, of water (well, a couple of times a year).

Edited by Onewheeler
Gobbledegook
  • Greenie 1

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NickNorman says it right. As these batteries are an unknown quantity a hydrometer is the quickest and easiest way to assess them. Get one, tell us the results and we might suggest what to do next. You probably wont get back to the full 1.277 but an equalisation might well get 1.26 or so which might be adequate for you needs. Trojans are good batteries so its worth spending a bit of time sorting them out.

 

Hydrometers are fiddle messy things but are a very useful to have.

 

................Dave 

  • Greenie 2

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33 minutes ago, dmr said:

NickNorman says it right. As these batteries are an unknown quantity a hydrometer is the quickest and easiest way to assess them. Get one, tell us the results and we might suggest what to do next. You probably wont get back to the full 1.277 but an equalisation might well get 1.26 or so which might be adequate for you needs. Trojans are good batteries so its worth spending a bit of time sorting them out.

 

Hydrometers are fiddle messy things but are a very useful to have.

 

................Dave 

Refractometers are better (less messy and fiddly), and under £20 from eBay eg
 

https://www.ebay.co.uk/itm/Portable-ATC-l-Refractometer/114254095573?hash=item1a9a1324d5:g:UQYAAOSwA6Be36R2

 

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46 minutes ago, nicknorman said:

Refractometers are better (less messy and fiddly), and under £20 from eBay eg
 

https://www.ebay.co.uk/itm/Portable-ATC-l-Refractometer/114254095573?hash=item1a9a1324d5:g:UQYAAOSwA6Be36R2

 

Refractometers are lovely instruments, and they do feel like an instrument whilst hydrometers generally feel cheap and nasty. However they do not stir up the acid which I suspect is sometimes important, and lifting out a tiny blob of acid is a potential "hole in the trousers" risk. I prefer the two rotating disc" type hydrometers though I can't find any just now or I would have posted a link. They do automatic temperature compensation but do need a bit of care to get decent results and also I have seen some sample to sample variation. Myself and mtb compared our two disc devices with Mikes refractometer and did find differences, though not huge.

 

.....................Dave

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Do you mean one of these hydrometers

 

https://www.ebay.co.uk/itm/Pro-Hydrovolt-HYDRO-VOLT-Lead-Acid-Battery-Hydrometer-Electrolyte-Tester/322082591860?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

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21 minutes ago, JonesBoy said:

Yes thats the one, much easier to use than a conventional "floating stick" device. I think its important to keep it upright and its not always obvious when its full, and if its not quite full it gives a bad result. Give it a tap to make sure the discs are moving freely. Rinse out well after use but the red and green will still fade.

 

Mine was about "1" out in that it would read 12.7 when it was really 12.6 so if you want to be really accurate you could get a refractometer as well to do a calibration check.  In many cases its the cell to cell variation that is of most interest but its still nice to have an accurate reading.

I found it quite difficult to get an error of less than "1" when using a float type hydrometer due to the float sticking to the side and the meniscus uncertainty, the disc device is much easier to use.

 

.................Dave

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