How much Solar v Batteries? What do you have?

[Matt&Jo]

10 minutes ago, Bettie Boo said:

 

LOL - actually I think you'll find you are the one who has misunderstood the op on this occassion.

They simply asked what set up other power hungry boaters have, I answered the question asked; not by telling them how they should live and what electrical appliances they should or should not have on their boat, but rather what we have and the power supply needed to run it.  I didn't in anyway mean to imply our set up is how everyone else should have theirs, it just works for us and how we like to live.

& yes, you are correct; I should have stated that we've only been living & cruising on our boat for 4 years now and are still very much considered complete novices by the boating clique that have been doing it for 40+ years.  I've often meant to ask just how long does one need to be cruising/living on a boat before one is no longer considered a novice?

Yes we could all stand out in the rain for our bathing needs, or lite a fire pit on the tow path for our cooking needs; we could even get a couple of large stones and beat our dirty cloths on them using canal water to wash them, personally I'd prefer a few "home comforts" in "my home"

Maybe if more folks stopped judging/assuming how others live, or should live, it would be a wee bit nicer place

LOL - & to add insult to injury...we have a Pump Out & LOVE it

Boooooom and there we have it. Nuff said

[ditchcrawler]

18 minutes ago, Bettie Boo said:

 

 

& yes, you are correct; I should have stated that we've only been living & cruising on our boat for 4 years now and are still very much considered complete novices by the boating clique that have been doing it for 40+ years.  I've often meant to ask just how long does one need to be cruising/living on a boat before one is no longer considered a novice?

 

Its a bit like living in a village, if your not born there you are always a new commer

[Dr Bob]

8 hours ago, WotEver said:

There's a fair bit wrong with the above paragraph. Taking the last bit first, 5 times faster than what? Up to 5 times faster than an old alternator with a low voltage regulator, poor wiring and split charge batteries? Maybe. 5 times faster than a modern alternator with a 14.6V regulator, correctly specced cables and no diodes in the charging circuit? No way. 

An AtoB charger doesn't 'fool' anything, it simply raises the charging voltage to the optimum for your batteries. If the alternator is already supplying the correct charging voltage at the batteries then an AtoB will do nothing. 

The last thing to bear in mind is that it's the batteries which determine the charging current, not the charge source. By way of example, a modern Beta with a 175A domestic alternator, correctly installed, will charge the batteries optimally with absolutely no external kit required. 

I was trying to keep it simple and not get too technical. In my experiencethe AtoB did work very well and was 5 times faster than without. Our system was 420 Ahr of batteries (new at first) being charged by a 70A alternator. The boat was new, using a Volvo Penta engine - so new alternator/wiring. My comments were about the ability to charge the batteries from circa 85/90% to full - which is where the OP is going to be if he has upwards of 600Ahr capacity. Before we fitted the AtoB, at 85/90% capacity, the alternator would start by putting in 25amps or so but this would fall very quickly to 5 -10amps and take over 5 hrs to get to 100%. This was on a Sailing yacht were you didnt want to have to run the engine for more than half an hour to get out of your berth. We fitted the AtoB and found that the initial charge was 40 amps but it was sustained at this level for much longer. Less than an hour was needed to get up to 100%. In our case it was 5 times faster and it was new kit (albeit smaller capacity etc). We lived aboard for 3 years and in the 5 years we had the boat, the battery performance did not seem to deteriorate.

I am sure you are right in saying a modern Beta with 175A domestic alternator  is the bees knees, but not everyone will have that.

Our current boat doesnt but with 700Ahrs of capacity and a 90A alternator, I am happy to run it a few hours to put the amps back in.

[MtB]

On 15/07/2017 at 16:52, Dr Bob said:

I was trying to keep it simple and not get too technical. In my experiencethe AtoB did work very well and was 5 times faster than without. Our system was 420 Ahr of batteries (new at first) being charged by a 70A alternator. The boat was new, using a Volvo Penta engine - so new alternator/wiring. My comments were about the ability to charge the batteries from circa 85/90% to full - which is where the OP is going to be if he has upwards of 600Ahr capacity. Before we fitted the AtoB, at 85/90% capacity, the alternator would start by putting in 25amps or so but this would fall very quickly to 5 -10amps and take over 5 hrs to get to 100%. This was on a Sailing yacht were you didnt want to have to run the engine for more than half an hour to get out of your berth. We fitted the AtoB and found that the initial charge was 40 amps but it was sustained at this level for much longer. Less than an hour was needed to get up to 100%. In our case it was 5 times faster and it was new kit (albeit smaller capacity etc). We lived aboard for 3 years and in the 5 years we had the boat, the battery performance did not seem to deteriorate.

I am sure you are right in saying a modern Beta with 175A domestic alternator  is the bees knees, but not everyone will have that.

Our current boat doesnt but with 700Ahrs of capacity and a 90A alternator, I am happy to run it a few hours to put the amps back in.

 

Now I'm curious. How were you determining '100%'?

[mrsmelly]

1 minute ago, Mike the Boilerman said:

 

Now I'm curious. How were you determining '100%'?

A smartgauge  

[MtB]

On 15/07/2017 at 16:58, mrsmelly said:

A smartgauge  

 

That's what I was worried about!

[Dr Bob]

13 minutes ago, Mike the Boilerman said:

 

Now I'm curious. How were you determining '100%'?

Combination of replacing the amps that had been taken out overnight - as measured by a amp hour counter, and then the alternator amps in dropping to 2-3amps which usually seemed to co-incide. We also had a Sterling battery charger that was used when we were on shore power that achieved 100% (I assume) so we had a base line from which to measure Amps out. I was a bit of a power nerd, and watched and plotted the volts and amps all the time. Probably had enough data to write a model for the voltage (similar to the Smartgauge!). I prefer amps in and amps out, but of course that doesnt tell you the capacity of the bank if it has deteriorated.

[Tony Brooks]

On 14/07/2017 at 21:56, Dr Bob said:

oring).

Running the engine is the only answer, but if finance is not an issue, buy an alternator to battery charger. This fools the alternator into thinking the batteries need charging and thus the alternator puts out more charging voltage. We had a Sterling unit on our boat which worked great and you could see 50-60amps going into the batteries for many hours. I think Sterling claim that it charges the batteries 5 times fast which is what we saw.

The only way to put that many amps into even a half charged typical battery bank is to elevate the voltage. This is what the A to B does BUT the degree to which it can be elevated is limited. If you overcook it you will do the same to the batteries. You may well have seen those figures but my question to you is how many of those amps were being converted to chemical energy, how many were producing heat, and how many were causing gassing - gassing can make charging worse because some say the bubble son the plates 2insulate2 them to a degree so they an not charge as fast as bubble free plates. Such devices will reduce the charging time to a degree but not as much as the Sterling bumph would have you believe. For teh first part fo charging it can only sit there the alternator is at full ouput without any help. During the second stage it will elivate the voltage to a limited extent but it will probably pulse on and off so that reduces the time it is acting. During the third stage the batteries will only accept  a small charge and trying to force the issue with excess voltage will damage them or dry them  I doubt you will save more than an hour or two over a day, probably less. Such devices will hide deficiencies in the existing charging system. they will not cure them and often its cheaper to cur than cover up.

My advice is to find the safe maximum charging voltage for your batteries (probably between 14.5 and 14.7) and get an alternator voltage regulator set to that or just below. In winter do most of the charging early in the day and let any solar provide the many hours of low current the batteries need.

[cuthound]

Just putting back the amp-hours you have taken out is not enough to fully charge a battery.  Typically you will need to put back 20% more than you take out.

However the good news is that you are monitoring tail current. Ideally keep charging until it ha dropped and remains steady at 1-2% of actual capacity.

[Dr Bob]

8 hours ago, Tony Brooks said:

During the third stage the batteries will only accept  a small charge and trying to force the issue with excess voltage will damage them or dry them  I doubt you will save more than an hour or two over a day, probably less. Such devices will hide deficiencies in the existing charging system. they will not cure them and often its cheaper to cur than cover up.

 

My comments were all about the later stages of charging as it sounded like the OP was talking large battery bank and a useage of 100A per day (my interpretation of the numbers that had some dubious values in them). On our yacht, we therefore got away with charging for 30mins to an hour rather than 2-3 hrs -which was important as we were sailing not motoring (ie your one to two hours a day). The AtoB worked well for us. The batteries (cheap end 110A lesiures) worked well for 5 years until we sold the boat. Only once went down to 50% charge and only below 80% a few times so they were looked after. Never saw the negative effect of overvoltage.

[WotEver]

5 minutes ago, Dr Bob said:

On our yacht, we therefore got away with charging for 30mins to an hour rather than 2-3 hrs

Sorry, but this is impossible. You cannot take lead acid batteries from 80% to 100% in 30-60 mins. It cannot be done. The chemistry prevents it. 

[MtB]

On 16/07/2017 at 19:14, WotEver said:

Sorry, but this is impossible. You cannot take lead acid batteries from 80% to 100% in 30-60 mins. It cannot be done. The chemistry prevents it. 

 

Changed my mind.

Edited July 16, 2017 by Mike the Boilerman

[WotEver]

7 minutes ago, Mike the Boilerman said:

Changed my mind.

Nahhh... go on

[Tony Brooks]

1 hour ago, WotEver said:

Sorry, but this is impossible. You cannot take lead acid batteries from 80% to 100% in 30-60 mins. It cannot be done. The chemistry prevents it. 

Ahh, but if the batteries were say 80% discharged with a meter that was giving false info you might be able to get them from 80% discharged to 50% in a short time when maybe the meter said 100%. Especially if the batteries were well sulphated an down on capacity.

[WotEver]

3 minutes ago, Tony Brooks said:

Ahh, but if the batteries were say 80% discharged with a meter that was giving false info you might be able to get them from 80% discharged to 50% in a short time when maybe the meter said 100%. Especially if the batteries were well sulphated an down on capacity.

Absolutely.

You can get to 50%, 60%, 70% or 80% very quickly, as you know. And if your meter is telling you that you're at 100%...

T

[Dr Bob]

1 hour ago, WotEver said:

Absolutely.

You can get to 50%, 60%, 70% or 80% very quickly, as you know. And if your meter is telling you that you're at 100%...

T

 

I was referring to 80-90% charge. I also said the AtoB started at 40A and kept it at this for much longer. Therefore to go from 90 towards full was not much more than an hour. OK, maybe only 95-97%.

The point I was trying to make was that the AtoB was far better to get to that level of charge than the straight alternator which within a short time was charging at less than 5 amps. It then took a few hours more to put back in what had gone out. 

Maybe you are right that I wasn't getting to full charge as I was using amps in vs amps out (as well as charging Amps down to 2-3) but I was looking at the comparison to that state of charge, whatever that state of charge was - to me it didn't really matter as long as state never went below 80% (which was likely less given all the flack I am taking here on state of charge) but the strategy worked as they lasted at least 5 years and possibly more. The AtoB worked better. 

The battery monitor, if I remember rightly was a BEP one, which 10 years ago seemed to be pretty sophisticated.

[WotEver]

Sorry, but it's impossible to charge anywhere close to 100% in anything less than several hours. It has nothing to do with the charge source and everything to do with battery chemistry. 

See this quote: "the remaining 30 percent [from 70% SoC] is filled with the slower topping charge that lasts another 7–10 hours. The topping charge is essential for the well-being of the battery"

From here: 

http://batteryuniversity.com/learn/article/charging_the_lead_acid_battery

Certainly you can get that 7-10 hours down to maybe 5-6 hours at some expense of battery capacity (increased internal corrosion and shedding) but it is completely impossible to get it down to <60 mins. 

[WotEver]

13 minutes ago, Dr Bob said:

The battery monitor, if I remember rightly was a BEP one, which 10 years ago seemed to be pretty sophisticated.

You might want to read through the OP here: http://thunderboat.boards.net/thread/867/battery-state-charge-meters-tell

[MtB]

On 16/07/2017 at 22:50, WotEver said:

 

Certainly you can get that 7-10 hours down to maybe 5-6 hours at some expense of battery capacity (increased internal corrosion and shedding) but it is completely impossible to get it down to <60 mins. 

 

Unless you rely on your SmartGauge telling you 100% SoC, obviously!

 

[WotEver]

Just now, Mike the Boilerman said:

Unless you rely on your SmartGauge telling you 100% SoC, obviously!

Regardless of the fact that the instructions tell you not to do that the fact remains that you can get that 7-10 hours down to maybe 5-6 hours at some expense of battery capacity (increased internal corrosion and shedding) but it is completely impossible to get it down to <60 mins. 

[Dr Bob]

6 minutes ago, WotEver said:

You might want to read through the OP here: http://thunderboat.boards.net/thread/867/battery-state-charge-meters-tell

Thanks for the link. Yes, I had read this before. We also had some solar to top up and a wind/water genny which did achieve full charge at least every other day so mainly we were 'nearly' fully charged.

[Dr Bob]

15 minutes ago, WotEver said:

Sorry, but it's impossible to charge anywhere close to 100% in anything less than several hours. It has nothing to do with the charge source and everything to do with battery chemistry. 

See this quote: "the remaining 30 percent [from 70% SoC] is filled with the slower topping charge that lasts another 7–10 hours. The topping charge is essential for the well-being of the battery"

From here: 

http://batteryuniversity.com/learn/article/charging_the_lead_acid_battery

Certainly you can get that 7-10 hours down to maybe 5-6 hours at some expense of battery capacity (increased internal corrosion and shedding) but it is completely impossible to get it down to <60 mins. 

Right let's rewind.

After a night at anchor we had used 40 A. 30 mins to an hour of engine with An AtoB brought that up to a state of charge a lot faster than no AtoB. Battery bank 440amp. Maybe the state of charge was not 100%. Let's assume it was only 95%. Maybe it was even less. Maybe I should be saying how long it took to put 40A ( as per the meter- which may only be 35 A true) back in. The AtoB was faster. Voltage at rest was fine. The batteries lasts 5 years and more. I am looking at a comparison here.

Have you tried an AtoB? I lived with one for 4.5 years. 

 

[WotEver]

My guess is that you were recharging with the engine to around 80% SoC. Certainly solar and wind would help a lot to increase that over several hours thereafter and would contribute greatly to battery life.

If you've used, to take your example, 40Ah then you'd need to replace around 50Ah to get back to where you started. If you're consuming any power at the same time then obviously that 50Ah needs to increase correspondingly  

An AtoB cannot help when the SoC is above 80%. As I have repeated several times in this thread (and as Battery University confirms) the last 20-30% of the charge is dictated by the battery chemistry and not the charge source. It takes several hours to get a lead acid battery from around 75% to 100% and that can't be changed. 

[Dr Bob]

8 hours ago, WotEver said:

An AtoB cannot help when the SoC is above 80%. As I have repeated several times in this thread (and as Battery University confirms) the last 20-30% of the charge is dictated by the battery chemistry and not the charge source. It takes several hours to get a lead acid battery from around 75% to 100% and that can't be changed. 

I am going to disagree.

In an earlier post, you said my first statement was wrong in that the AtoB fools the alternator into charging at a faster rate. The Sterling charger reduces the voltage from the alternator - not increases thus fools it - and not increases voltage as you say. It is  not the same as other Ato B units.

It is a fact that we got more amps into our batteries with the Sterling unit.  Probably 25% of the boats we knew had these units and the owners saw the benefit.  No one in the NB world seems to use Sterling which is surprising considering the number of sailing boats that use them. I doubt Sterling would be in existence if your coments above are true as they would have been hammered by Trading Standards. Sterling do not quote at what stage of charge their Ato B units are 500% more efficient but for us we saw a big efficiency change at the higher end of charging.

Rather than continually saying the chemistry doesnt allow faster charging, why not consider the facts that people who actually use this kit see a benefit. If I had another yacht I would certainly add a Sterling AtoB. I am holding off doing so on my NB as I run the engine far more and it seems to charge far better at tickover than the Volvo unit I had.

 

[MtB]

On 17/07/2017 at 09:00, Dr Bob said:

I am going to disagree.

In an earlier post, you said my first statement was wrong in that the AtoB fools the alternator into charging at a faster rate. The Sterling charger reduces the voltage from the alternator - not increases thus fools it - and not increases voltage as you say. It is  not the same as other Ato B units.

It is a fact that we got more amps into our batteries with the Sterling unit.  Probably 25% of the boats we knew had these units and the owners saw the benefit.  No one in the NB world seems to use Sterling which is surprising considering the number of sailing boats that use them. I doubt Sterling would be in existence if your coments above are true as they would have been hammered by Trading Standards. Sterling do not quote at what stage of charge their Ato B units are 500% more efficient but for us we saw a big efficiency change at the higher end of charging.

Rather than continually saying the chemistry doesnt allow faster charging, why not consider the facts that people who actually use this kit see a benefit. If I had another yacht I would certainly add a Sterling AtoB. I am holding off doing so on my NB as I run the engine far more and it seems to charge far better at tickover than the Volvo unit I had.

 

 

A few peripheral knit-pickings...

1) I can't help myself. I've held off saying this until now as I'm like a cracked record on this. I think you're using the wrong units here: "It is a fact that we got more amps into our batteries." I think you should be saying "It is a fact that we got more amp-hours into our batteries". This is important as new readers will struggle (as I did when I first started learning in depth about battery charging) to understand  why amps are being quoted when it ought to be amp-hours. 

2) "500% more efficient"? Another technically meaningless term in my view! Charges five times quicker, I think Sterling claim. Also meaningless. I think they should say "charges in 20% of the time", which makes much more sense.

3) Like you, I find battery charging has sublime aspects never quite explained by the technicians. I'm staggered your cheapo batteries lasted five years when my expensive ones lasted five months when I looked after mine almost correctly, but not quite, just as you did. And the anecdotes here about how gel batteries take so much more abuse than wet lead acid never seem to be fully explained either by applying conventional battery chemistry knowledge