How much Solar v Batteries? What do you have?

[WotEver]

4 minutes ago, nb Innisfree said:

ETA: Can't do multiple quotes on my phone anyway. 

You can... you need to persevere to see how

I do 99% of my posting on a phone. 

Just now, cereal tiller said:

I always agree with your advice Rusty,only then do I ignore it

I've found that's generally the best thing to do with my advice too

[Cpickle]

7 hours ago, dmr said:

There a fair bit of crap getting posted on this thread, I might write something later, but its a sunny day and there's big maintenance to get done.

Standard cheapo leisures are good for about 300 cycles (down to about 50%). No matter how well one maintains then they are unlikely to do much better than this. If not looked after then its a lot less than 300 and as Mike says they do appear to go down to a low capacity and then stick there.

If batteries last 5 years that's because either they have not done many cycles or the owner is happy to live with hugely reduced capacity.

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

So does this mean a standard battery could last less than a year? If I am charging my batteries to 12.8 (which I understand is full) and going down to maybe 12.2 every day?! 

 

 

[Tony Brooks]

1 hour ago, Dr Bob said:

Ah, very useful. So for a 100-50% cycle, these Trojans will do 1500 and for 100-80% they will do almost 3 times more. I will do a bit of searching on wet lead acids. This is why I was always told to not drop below 80% when we first started sailing.

Its not just not letting them drop below XX% but getting them recharged ASAP after discharge as Mike likes to remind us. letting them sit at (say 25% discharged for several weeks will induce sulphation.  Its best to think about any quoted maximum % of fully charged figure as a warning that you must start charging NOW and if that is not possible in the next few hours.

It is also interesting to note that Trojan's open circuit rested voltage figure are lower than many other makes and the general consensus. This means that whatever anyone thinks any examples or discussion based on readings can never be 100% factual unless you also have access to ALL the battery manufacturer's data.

[WotEver]

3 minutes ago, Tony Brooks said:

It is also interesting to note that Trojan's open circuit rested voltage figure are lower than many other makes and the general consensus.

They state pretty categorically that the way to determine charge status is by measuring the specific density of the cells. It reads almost as a grudging "well, you could read voltage if you really must" from them. 

Edited July 18, 2017 by WotEver

[nb Innisfree]

20 minutes ago, WotEver said:

You can... you need to persevere to see how

I do 99% of my posting on a phone. 

Time was when I would have persevered but to be honest I can't be arsed! 

[Cpickle]

Thanks again to all for the advice. I think I need to read through all your comments a few times in order to understand them. But so far I think it sounds like: 

* I was planning for more solar than I likely need during summer. 

*  No point getting loads extra for winter because it isn't going to help that much. 

* Most people just run the engine to charge in winter, or have a whispergen (these don't seem to exist any more?) or other genny . The AtoBs don't help charge faster but a bigger alternator does? So perhaps I should look at upgrading the Alternator and get a hospital silencer?  This is my engine, http://www.canaline-engines.co.uk/new-build/canaline-60-marine-engine/. So 170 Alternator already. 

* I need a good controller if I am to manage batteries properly. If I reduce to 1000w solar, I think this means I need a 80ah Controller. Bimble Solar suggested I could get 4 20ah controllers to save costs instead of one big one. Is this a massive mistake? 

* As suggested above, standard batteries have a 300 cycle use from 100-50 - so this means they could last me less than a year even if I am only discharging to 12.2? Good batteries like Trojan might last me 3 x that and longer if I only go down to 80%. It seems to me like it would be really hard to only go down to 80% each day. If I use most of my electricity in the evening, is it not likely I will be getting down to 50 most nights before the sun rises again or I wake up to turn engine on? 

Is it crucial that I understand all the really technical stuff as you are debating above? I'm really just trying to get a basic knowledge so that my system suits my needs and I don't ruin everything within a few months of having the kit. I've kind of accepted that I'm probably the kind of user that's going to need to replace the batteries every 3 years by the sound of what I read on these forums. 

 

Cait 

 

[WotEver]

9 minutes ago, nb Innisfree said:

Time was when I would have persevered but to be honest I can't be arsed! 

I'm rapidly getting to the same stage. 

[Cpickle]

Also. If I currently have 3 x Platinum 110ah batteries, would it be best to get more of the same or could I get 3 more 220 batteries for instance? And can I mix brands? Some brands all seem to be the same battery with different brand stickers on for example, I'm sure the premium ones aren't like that though. 

[rusty69]

7 minutes ago, Cpickle said:

I think I need to read through all your comments a few times in order to understand them.

I wouldn't, you'll end up going mad....I have

 

Whatever you end up doing,try to have the relevant gadgets/meters to determine when you need to start charging and when you can stop.

Edited July 18, 2017 by rusty69

[WotEver]

1 minute ago, Cpickle said:

Is it crucial that I understand all the really technical stuff as you are debating above?

No

Getting a decent solar installation will sort you out up to say mid October and then again from mid March. The vagaries of the English climate can move those dates in either direction. 

Decent batteries like Trojans are good for something like 1700 cycles down to 50% as long as they're charged correctly on a daily basis. If you occasionally only go down to 60% SoC then that 1700 might go up to 2000. So at worst they'll be good for about 5 years. 

Ignore the arguments

[Cpickle]

7 minutes ago, WotEver said:

No

Getting a decent solar installation will sort you out up to say mid October and then again from mid March. The vagaries of the English climate can move those dates in either direction. 

Decent batteries like Trojans are good for something like 1700 cycles down to 50% as long as they're charged correctly on a daily basis. If you occasionally only go down to 60% SoC then that 1700 might go up to 2000. So at worst they'll be good for about 5 years. 

Ignore the arguments

Thank you. The simpler the better for me!  Looking at purchasing some Trojans now, does this mean I would need to get rid of my other 110ah platinum batteries? 

 

 

[WotEver]

33 minutes ago, Cpickle said:

Looking at purchasing some Trojans now, does this mean I would need to get rid of my other 110ah platinum batteries? 

Yes, because the charging voltages are different. Before you buy Trojans do ensure that you can charge them at their optimal rate. This might mean buying some kind of alternator controller, or a Sterling AtoB, or whatever. Also note that Trojan T105s are only 6V, so you'll have to buy them in pairs, plus they're physically much bigger than 'ordinary' batteries.  

[Paringa]

Note to self - never get involved in forum battery threads

[Robbo]

13 hours ago, Cpickle said:

Thank you. The simpler the better for me!  Looking at purchasing some Trojans now, does this mean I would need to get rid of my other 110ah platinum batteries? 

 

 

If you really want to splash out and can afford them go LifePo4.  These type of batteries are more suitable for a off grid lifestyle when you can’t or don’t want to charge to 100% regularly.  They are good for heavy users as the voltage is fairly consistent through the SoC and load.

You are looking at a battery bank costing initially £3-5K tho.  Although long term you are potentially saving money.

[cuthound]

22 hours ago, Dr Bob said:

Mike, I didnt mean to insult you and apologise if that is the way it came over. Your experience is real and shows that it doesnt always go by the book.  There is more to it than the chemistry that has been documented here.

In our case we hadnt lost 50% of our capacity in years 2,3 etc as the voltage at rest showed more capacity than that but cant remember the exact number. We started with 440Ahr so a 50% decrease would have had a significant effect on days when we used 80 Ahrs.

With due respect, the bit I have highlighted shows that you don't fully understand battery charging. 

Resting voltage will show state of charge  (as will electrolyte specific gravity) but SoC is not related to capacity. A battery will show 100% charged voltage whethere it has 100% or 1% of its original capacity. 

Capacity can be measured using an amp-hour counting meter, but every organisation that I have worked for where power was critical to operation, tested capacity every two years by discharging the batteries to a test load and measuring current and time. These are the only ways to assess actual battery capacity. Also when recharging a battery you will typically need to put in 120-130% more amp-hours than you took out.

 

Edited July 19, 2017 by cuthound
Spillung

[WotEver]

11 minutes ago, cuthound said:

With due respect, the bit I have highlighted shows that you don't fully understand battery charging. 

I was going to pick up on that myself but I gave the poster the benefit of the doubt as to him actually meaning "Resting voltage combined with Ah out, showing amount of discharge..." even though he didn't say so. 

Perhaps I shouldn't have done?

[cuthound]

6 minutes ago, WotEver said:

I was going to pick up on that myself but I gave the poster the benefit of the doubt as to him actually meaning "Resting voltage combined with Ah out, showing amount of discharge..." even though he didn't say so. 

Perhaps I shouldn't have done?

Hopefully he will come back and clarify, however as written it is wrong, we both know there is no relationship between resting  voltage and capacity.

Still playing catch up with the forum having been away for the weekend, so having to comment after the event rather than join in the discussion. 

Edited July 19, 2017 by cuthound
To add the last sentance.

[Tony Brooks]

I have just logged on and when I read that bit I immediately wanted to reply to explain why it was wrong but then I thought "why bother, he seems convinced that he knows all he wants or needs to about alternators, batteries and charging so why waste my time".

Its others with even less knowledge that concern me. If we do not try to explain why certain statements are just plain wrong others could end up spending money they maybe do not need to or only hide faults that are still there.

[Sea Dog]

14 hours ago, Cpickle said:

The simpler the better for me!  Looking at purchasing some Trojans now... 

 

 

Hmmm. Those two statements don't really go together. Trojan's may be a good solution for your situation, but it sounds like you'll struggle to look after them. It's a truism that you can kill top quality batteries as quickly as cheap ones by a poor charging and maintenance regime. I'd have thought it better for you to learn on a set of cheaper sealed batteries, and progress to something like Trojan's once you're confident should you see advantage in the extra investment. 

[WotEver]

16 minutes ago, Tony Brooks said:

Its others with even less knowledge that concern me. If we do not try to explain why certain statements are just plain wrong others could end up spending money they maybe do not need to or only hide faults that are still there.

Good point

[Paringa]

31 minutes ago, Sea Dog said:

Hmmm. Those two statements don't really go together. Trojan's may be a good solution for your situation, but it sounds like you'll struggle to look after them. It's a truism that you can kill top quality batteries as quickly as cheap ones by a poor charging and maintenance regime. I'd have thought it better for you to learn on a set of cheaper sealed batteries, and progress to something like Trojan's once you're confident should you see advantage in the extra investment. 

I said the same...

[MtB]

On 19/07/2017 at 07:42, Robbo said:

If you really want to splash out and can afford them go LifePo4.  These type of batteries are more suitable for a off grid lifestyle when you can’t or don’t want to charge to 100% regularly.  They are good for heavy users as the voltage is fairly consistent through the SoC and load.

You are looking at a battery bank costing initially £3-5K tho.  Although long term you are potentially saving money.

 

I'd strongly contradict this advice for the OP as a newbie.

LiFePo4 batteries need very specific charging and management and the equipment to do this simply isn't widely available. Dedicated chargers are madatory, yet I've seen websites selling these batteries yet barely touching on LiFePo4 charging systems and equipment.

BEWARE. Charging them cannot be done with an ordinary boat engine alternator or Halfords battery charger. If fact it would be very dangerous so to do. 

[peterboat]

15 hours ago, Cpickle said:

Thank you. The simpler the better for me!  Looking at purchasing some Trojans now, does this mean I would need to get rid of my other 110ah platinum batteries? 

 

 

Look on ebay GTP batteries arnt much more expensive than Trojans and are tougher, I know which I would spend my money on.

Plus on the controller side, buy just one I had two operating together and it didnt go well [they were identical]

Edited July 19, 2017 by peterboat

[rusty69]

5 minutes ago, peterboat said:

Look on ebay GTP batteries arnt much more expensive than Trojans and are tougher, I know which I would spend my money on.

Plus on the controller side, buy just one I had two operating together and it didnt go well [they were identical]

They look good. Any real world experience yet? 

[peterboat]

2 minutes ago, rusty69 said:

They look good. Any real world experience yet? 

The americans have been using them for years in cars, so plenty of experience for them, very long lived, and they are what I am going to fit in my electric boat.

I wouldnt bother with Li-po as sodium batteries are just around the corner which because of cost, I think deal a death blow to Lithium technology