Sealed or open wet cell battery's?

[Guest]

A lot of people report that their batteries last longer with solar charging. I hope its true for us.

 

Top Cat

Time will tell. We abuse batteries I'm afraid, though less so these days without teenagers aboard. Still the washer and suchlike give them some grief.

[Top cat]

Our batteries get an easy life, rarely discharged below 90% and usually fully recharged the next day. The lowest I have seen is 78% which leads me to wonder whether I could have got away with a much smaller bank ( 4 × 110 Ah sealed liesure). Something I will consider next time.

I think in 2 1/2 years the capacity has dropped about 15% but thats a guess as I haven't done a formal test.

 

Top Cat.

[tidal]

I believe that batteries' lives are greatly affected by their average voltage. If they're solar supported, they'll spend all day at a decent voltage, 13 or so, if the system is balanced ok.

 

If they're not solar supported their voltage will be much lower all day, except for short periods of recharging.

 

 

That is supported by my experience of similar use on yachts on the salty stuff.

Though in those boats the supporting charge was provided by wind rather than solar

 

 

 

 

[by'eck]

I believe that batteries' lives are greatly affected by their average voltage. If they're solar supported, they'll spend all day at a decent voltage, 13 or so, if the system is balanced ok.

 

 

Even leaving batteries long term on float has its downside although much prefeable to leaving them with no charge at all. The electrolyte becomes stratified with lack of battery use. That's why good mains chargers have an auto pseudo equalise mode evey 14 days or so where the charger is cycled into the absorb mode for an hour or so. Better still to use them though. Mine always seem more responsive once I've made a short term high current discharge on them after boat has been laid up.

[Naughty Cal]

I believe that batteries' lives are greatly affected by their average voltage. If they're solar supported, they'll spend all day at a decent voltage, 13 or so, if the system is balanced ok.

 

If they're not solar supported their voltage will be much lower all day, except for short periods of recharging.

 

More sulphation occurs at lower voltages.

 

NC, do you have 'good' batteries, or the cheapest you can find? I've always been disappointed with cheapos and very pleased with good ones. I would rather buy good ones less often, than replace cheap ones every 2 years. Lugging them to the scrappies is a real pain.

Not the cheapest. We use Varta.

[Guest]

Not the cheapest. We use Varta.

Varta did OK on our boat given the abuse that they got.

[Graham.m]

The most important thing about battery systems in narrow boats is their charging system. It must be matched to the type of batteries you have. If it is not it will shorten the life of the batteries that you have.

 

All batteries are sensitive to overcharging and being charged at the wrong voltage.

 

Fllood (unsealed) are the most forgiving and just boil off their water which can be replaced.

Gel & AGM Batteries are less forgiving in that once you have boiled the water off it cannot be replaced

 

From my knowledge and experience to get the best use from your batteries and value from your batteries

 

The mains charger should be capable of supplying a charging rate of between a 1/20 and 1/10 of the battery bank capacity

The charger should be at a minimum a three stage charger and measure the temperature of the batteries as they charge and adjust charge and voltage dependant on that temperature.

 

The most import thing is the charging voltages (for a 12v Bank, double for a 24V, quadruple for 48V)

 

A flood battery is quite happy accepting a charge voltage of 14.8V and a maintenance charge voltage of about 13.8.

 

However a sealed battery is in danger of boiling off its water if charged at more that 14.4V. That water cannot be replaced. Alway check with the supplier/manufacturer what their recommendations are for the charging of their batteries.

 

Now not only does the above apply to solar panel systems it also applies to the boat's alternators. The whole of the charging system needs to be matched to the batteries installed on the boat or that you are thinking of changing to.

 

There is a lot of talk about rapid charging of batteries. The faster you charge them the shorter their life will be. Don't expect a battery bank to be fully charged from 50% DOD is a couple of hours it will take of the order of 10 to 15 hours assuming a perfectly matched charger. Flood and AGM take a charge faster than Gel.

 

:-) Tin hat on :-)

[Naughty Cal]

Varta did OK on our boat given the abuse that they got.

Ours tend to get shaken around when we are at sea which they don't seem to appreciate!

[Guest]

Ours tend to get shaken around when we are at sea which they don't seem to appreciate!

Interesting, hadn't really thought about that. I expect a lot of banging around can loosen things inside the batteries.

I have seen a couple of car batteries do spectacular things when we used to race bangers, so I expect the end result is similar.

[Loafer]

The most important thing about battery systems in narrow boats is their charging system. It must be matched to the type of batteries you have. If it is not it will shorten the life of the batteries that you have.

 

All batteries are sensitive to overcharging and being charged at the wrong voltage.

 

Fllood (unsealed) are the most forgiving and just boil off their water which can be replaced.

Gel & AGM Batteries are less forgiving in that once you have boiled the water off it cannot be replaced

 

From my knowledge and experience to get the best use from your batteries and value from your batteries

 

The mains charger should be capable of supplying a charging rate of between a 1/20 and 1/10 of the battery bank capacity

The charger should be at a minimum a three stage charger and measure the temperature of the batteries as they charge and adjust charge and voltage dependant on that temperature.

 

The most import thing is the charging voltages (for a 12v Bank, double for a 24V, quadruple for 48V)

 

A flood battery is quite happy accepting a charge voltage of 14.8V and a maintenance charge voltage of about 13.8.

 

However a sealed battery is in danger of boiling off its water if charged at more that 14.4V. That water cannot be replaced. Alway check with the supplier/manufacturer what their recommendations are for the charging of their batteries.

 

Now not only does the above apply to solar panel systems it also applies to the boat's alternators. The whole of the charging system needs to be matched to the batteries installed on the boat or that you are thinking of changing to.

 

There is a lot of talk about rapid charging of batteries. The faster you charge them the shorter their life will be. Don't expect a battery bank to be fully charged from 50% DOD is a couple of hours it will take of the order of 10 to 15 hours assuming a perfectly matched charger. Flood and AGM take a charge faster than Gel.

 

:-) Tin hat on :-)

 

No artillery fired.

 

Sounds good to me.

[Graham.m]

 

No artillery fired.

 

Sounds good to me.

 

:-) It is good just wish boaters would be wise

[by'eck]

The most important thing about battery systems in narrow boats is their charging system. It must be matched to the type of batteries you have. If it is not it will shorten the life of the batteries that you have.

 

All batteries are sensitive to overcharging and being charged at the wrong voltage.

 

Fllood (unsealed) are the most forgiving and just boil off their water which can be replaced.

Gel & AGM Batteries are less forgiving in that once you have boiled the water off it cannot be replaced

 

From my knowledge and experience to get the best use from your batteries and value from your batteries

 

The mains charger should be capable of supplying a charging rate of between a 1/20 and 1/10 of the battery bank capacity

The charger should be at a minimum a three stage charger and measure the temperature of the batteries as they charge and adjust charge and voltage dependant on that temperature.

 

The most import thing is the charging voltages (for a 12v Bank, double for a 24V, quadruple for 48V)

 

A flood battery is quite happy accepting a charge voltage of 14.8V and a maintenance charge voltage of about 13.8.

 

However a sealed battery is in danger of boiling off its water if charged at more that 14.4V. That water cannot be replaced. Alway check with the supplier/manufacturer what their recommendations are for the charging of their batteries.

 

Now not only does the above apply to solar panel systems it also applies to the boat's alternators. The whole of the charging system needs to be matched to the batteries installed on the boat or that you are thinking of changing to.

 

There is a lot of talk about rapid charging of batteries. The faster you charge them the shorter their life will be. Don't expect a battery bank to be fully charged from 50% DOD is a couple of hours it will take of the order of 10 to 15 hours assuming a perfectly matched charger. Flood and AGM take a charge faster than Gel.

 

:-) Tin hat on :-)

 

Brave words but how do you enact your suggestions in the real world? Specifically the low charge rate and 10-15 hours charge period, every day for most living off grid.

[Guest]

 

Brave words but how do you enact your suggestions in the real world? Specifically the low charge rate and 10-15 hours charge period, every day for most living off grid.

I think the words are perfectly correct in an ideal world, but my boat rarely sees shorepower. I have a standard alternator of 90A and use the genny sometimes via a 3 stage charger. I often wonder how my batteries survive as long as they do, since the charging regime is far from ideal. Hopefully Father Christmas is bringing solar panels, so maybe some improvement next year.

[ditchcrawler]

. Hopefully Father Christmas is bringing solar panels, so maybe some improvement next year.

But who will bring the sun shine?

[Guest]

But who will bring the sun shine?

 

My wife is a ray of sunshine so we should be OK

[Graham.m]

 

Brave words but how do you enact your suggestions in the real world? Specifically the low charge rate and 10-15 hours charge period, every day for most living off grid.

 

For starters there is a need to acknowledge that we are using a difficult to replace resource. Then we need to put the right equipment and batteries to do the job in the boat. For starters all lighting needs to be converted to LED, it may seem expensive on the face of it but in the long run it will save money and batteries. Inverters are a backup resource not a main resource and are as small as possible. Most boats only need a 350W inverter for day to day use, plus maybe a 2KW for the emergency, both pure sine wave. Normal AC, washing machines, vacuum machines, hairdryer run off an installed 3/4KW diesel generator as does the main battery charger. Plus of course a 16Amp shoreline

 

Now the battery bank needs to be sized such that the average usage if 20% of capacity and charged daily and not left for another day. A liveaboard would probably use, with gas for cooking, 60A/hs that would give a battery bank of 600A/h, charger would be a 60A unit. That would give a recharge time of 5 to 6 hours.

 

Alternator needs to be of the order of 60/70A and fully regulated.

 

If the boat is used to run an electrically hungry business run the generator it will run the business and charge the batteries at the same time using about a 1/3 litre of diesel per KW being used. A 60A charger will use approx 900W. So cheaper than a main engine running.

 

ED. Nearly forgot solar panels, at least 300W, preferably 600W with an MPPT controller.

 

Install separate charger, generator, inverter so that if there is a failure you only lose one item and not two as with a combi etc.

 

In the long term the same amount of money will be spent, probably more if a poor system is installed.

 

Just my thoughts

Edited November 8, 2015 by Graham.m

[ditchcrawler]

 

My wife is a ray of sunshine so we should be OK

Creep, or does she also read this?

[Guest]

Creep, or does she also read this?

She might read it, and I am in enough trouble already

[Top cat]

All good advice Graham

 

T C

[Loafer]

 

My wife is a ray of sunshine so we should be OK

 

I'm not completely satisfied that she'd be happy being strapped to the mast, pointed at the solar panels, on a damp dreary day though.

[Graham.m]

 

I'm not completely satisfied that she'd be happy being strapped to the mast, pointed at the solar panels, on a damp dreary day though.

 

I thought that is what the rays of sunshine were for. :-)

Heck now I know where I have been going wrong all these years

[peterboat]

Wrong. AGM batteries are better suited to deep discharges and rapid recharges than wet lead acid cells.

 

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

full traction batterries are designed for rapid and deep discharge milk floats etc mine are ten years old my supplier recently changed some at 25 years old my agms were knackered at 3 years old on the side it said 300 cycles how many have 25 year old full tractions done at a smaller cost for the battteries as well

[Graham.m]

full traction batterries are designed for rapid and deep discharge milk floats etc mine are ten years old my supplier recently changed some at 25 years old my agms were knackered at 3 years old on the side it said 300 cycles how many have 25 year old full tractions done at a smaller cost for the battteries as well

 

I agree they are on the face of it expensive but long term very economical. They are designed to discharge to 80% and recharge in 10 hours or so.

[cuthound]

full traction batterries are designed for rapid and deep discharge milk floats etc mine are ten years old my supplier recently changed some at 25 years old my agms were knackered at 3 years old on the side it said 300 cycles how many have 25 year old full tractions done at a smaller cost for the battteries as well

Yes I should have stated leisure batteries to be absolutely clear.

 

When I started work at BT, way back in the early 70's, one of my jobs was to look after the telephone exchange batteries for the London based international sites.

 

Some of those batteries were over 20 years old. Every 2 years they were subjected to a "conditioning cycle", whereby they were fully discharged (to 1.85 volts per cell) at the 10 hour rate (load adjusted every 15 minutes to compensate for the falling voltage) to assess actual capacity, before immediately recharging. A cadmium electrode (which is negative relative to the negative plate) was used to assess the condition of the plates, relative to each other. Used to work 30 hours straight, no slacking as sg readings and load adjustments were needed every 15 minutes, but very lucrative in overtime.

 

Don't think H&S would allow it nowadays, but superceded in 1980 when VRSLA's became the standard battery for BT.

 

Reminds me of a shared ownership meeting I attended once. One of the co-owners asked me what I thought of " Clift" batteries. "Never heard of them" I replied. "On, its just that we met a boater who said his four Clift batteries were the best batteries he had ever had"

Edited November 9, 2015 by cuthound

[Loafer]

ISTR that Lifeline AGMs were rated at 2000 charge cycles. Complete ones. Yer average Numaxes and other stuff are generally 400 max, but they won't tell you anyway 'cos it's so dismal.

 

Good ones are worth it, in my view, as long as they're looked after and charged properly. If you can't do that, get the cheapest you can find and chuck 'em when they start to die!