Hi All,

I recently acquired the Top Hat Fourth Lady, there are a couple of active top hat sailors on this forum I see! Great boat in great condition, a credit to the previous owners really!!

I'm planning a short 5 day trip on the boat and am just assessing my power needs... I've got a 100AH Remco battery, a dead secondary that needs replacing and a 20 watt solar panel for trickle charge. I have a nice 12hp witchards kabota diesel with a 30 amp Nippon denso alternator in great working condition..

I'm considering increasing the solar to top up batteries on short trips like this.. My thoughts are something like the Max Ray 120watt portable folding solar panel for use while moored? Anyone had any experience with these? They are $150 new.

Any thoughts on a cost effective replacement battery? Remco 100AH? Renogy 100AH? Am-tech 110AH...?

How many Amp Hours do other small boat owners carry for short trips? I'm considering a small Waeco Coolpro 21 to cool the essentials.. Any thoughts?

I'm moored on the lane cove river so any other lane cove sailors say hi!

Hi Toyboata,

Can't comment on all your questions but I have an Adams 28 with a 60w solar panel, an isotherm utecectic ASU fridge/freezer (150lt) and 2 batteries - 600cc 130rc and 720cc 160rc. I have only had the boat for about 18mths. In that time I have never not been able to start the 20hp 3 cylinder diesel Kubota engine never run-out of power. My boat lives on a swing mooring and the 60w panel has always kept the batteries topped up perfectly. I was told by the previous owner that the fridge is extremely energy efficient and the panel is sufficient to run the fridge too. I have to say that so far I have been unable to verify this as I sailed the boat in 2 stages from Esperance to Fremantle and managed to fry (suspected as there is nothing visually wrong with it) the circuit board on the fridge due to a leaky exhaust hose. I have only just replaced the board so we shall see. As the previous owners other claims have been proven to be accurate so far I am inclined to believe him in relation to the panel coping with the fridge.
Hope this is of some interest if not value to you.
I feel a need to add that my solar panel is on a frame so is very rarely in shadow.

Toyboata,

Could go on at length, but if you go across to www.tophatyachts.com you will find all the info there on what we have all done to our Top Hats.

But yes, I have found a 20w panel is not enough and you will be struggling.
Most of us use a 100w panel [because of weight] and mount on a frame over the stern.
As to the batteries I last purchased 7 years ago but will be replacing 2 house [120AH each] and 1 starter [100AH] batteries later this year.

I'm in the Camden Haven Inlet so I can't pop over

Toyboata
WaecoCoolpro21, might be a problem. Thermoelectric Cooler / Warmer
has Peltier device - not a compressor, means amperes thirsty. Can't find
how much. You can try 120 w panel plus 2 sets of batteries , see how you go, monitor voltage, if too low start the engine.

Wow, lots of great feedback!

Sounds like the fridge isn't going to happen...

@nswsailor - Phillip? I've read some of your blog, your posts on the top hat forum and also a couple of your comments on the facebook page!

I considered flexible solar but the panels are pretty pricey. A 100W in place of the 20W on the back frame will probably do the trick!

My experience for what it is worth:

I have a Compass 28 which has a 60W solar panel and MPPT regulator for the house battery, plus a separate 5W panel that trickles the start battery, hence they are always as close as possible to 100% charge when I go to sail.

On my multi-week cruises (Bass Strait, plenty of cloudy days) I have found that this set-up comfortably handles the loads, which include tiller-pilot, lights (almost all LED now), VHF, BiData log/depth, GPS/ plotter, laptop and sound system. I monitor things pretty closely as I am a retired electrical engineer and it's all very close to my heart. If I added a fridge I am sure I'd need a bit more solar capacity. However if I was further north (than Melbourne) and sailing during summer I might not need to.

Most small yachts will typically have something like a 80 - 120 Ah house battery. Whilst battery Ah capacity is important, it must be accompanied by adequate charging capacity and over a few days (versus day sailing), the latter is the more critical factor. Measure the current of each your loads in all their various operating modes with your multimeter, then you can compute how many Ah you will use per day (and night), both sailing and anchored, and then will be able to determine how much solar you need. I have found that my panels put out on average about 1/3 their nominal capacity in cloudy weather - ie something like 20Ah per day. This pretty much copes with the load. But when the sun shines the panels provide much more and win hands down.

I am a huge fan of the sealed second-hand UPS batteries that you can find on Gumtree or eBay fairly regularly - Google something like "used 80Ah battery". I have had a few of these and they last for 5 years or more with normal use (including not being run down below about 50% rated Ah). Although they are not designed for engine starting they will cope fine with starting your small diesel and hence can be used for both house and starting. I did manage to kill one by running it flat with the anchor winch (end of long solo passage, exhaustion, brain-dead, should have had engine running with batteries paralleled, but s%#t happens). They sell for about $1 per Ah and are terrific value compared with new batteries.

Make sure you get an MPPT regulator as they will pass about 30% more charge than the cheap PWM ones. You can pay hundreds, but I bought a Tracer brand 10A one over eBay, complete with display, for about $130 and it has served me admirably for 4 years now. I use a cheap PWM one on the 5W starter battery panel, which gives me a spare should the MPPT one cark it.

Your panels need to be "on" all the time during daylight hours, so forget about using folding ones at anchor (especially as the sun sets!). My panels are mounted on a 32mm SS tube, which is fixed to the pushpit and has a tee cross-piece at the top. Simple and cheap, has survived 50kn gusts, and has the benefit of being able to swivel and tilt the panels for best efficiency depending on relative sun/boat angle.

Your hardest task might be to assess the actual daily Ah load of a fridge under the various operating conditions you will encounter. But wtf as my kids say, just start the engine if you have to!
Hope this is of use, good luck with it all,

Graeme

Hi Toyboata
Chaarriot is correct, don't even consider Thermoelectric fridge. They are not suited to boats or for anything for that matter. Engel make the best portable fridge for a boat as the swing compressor they use is very efficient but whats more they are the least voltage conscious of all. Engel make two models with pvc outers that are very suitable for boats, their 15lt and 38lt Eclipse. I run the 38lt in the bow of my boat as a second freezer where is gets a fair share of saltwater and the 15lt in the car when we are away in the caravan. They are not cheap, but at least you are buying something that will do the job. Shop round, l saved $150 on the 15lt from BCF because they price matched the price advertised from Tent World on the net.
In relation to batteries, if you want good life and performance out of your batteries you should replace both batteries at the same time with identical ones. There are quite a number of technical reasons why that I will not go into in this post. Most importantly they should be sealed, maintenance free AGMs. My recommendation to you would be 2 x 115A/hr Fullriver batteries. (Or blow the budget and fit 1x 110A/hr Lithium)
www.fullriverbattery.com/product/dc115-12/
Your 30amp alternator will be OK for charging the 2 Batteries as the batteries will not take much more charge than that anyway. A100watt solar panel would be a minimum. The portable flexible Panel could be a good option in that you can probably position it to avoid shading, but would be a bit of a problem if you want to use it while Sailing
i got away without solar panels for years with my smaller boats by just using the motor to charge, but the big difference is I always had eutectic refrigeration.

Graeme you've given me a days work in that post! I've been scouring gumtree for a decent house battery.. Plenty there just need to decide what I need. $120 for 120AH and $130 for a new 100W solar panel is looking good! I'll chec my regulator is MPPT.. Seems to do the trick!

Jode5 as much as I'd love an Engel and top of the line matching batteries... Maybe next year $$$$$

Estimating energy consumption, charging and battery size requirements is not easy. As part of an electrical upgrade of my boat, I designed a useful spreadsheet.
Unfortunately, spreadsheet files can't be uploaded to this forum, but the pic below might show what it does.
Red cells are calculated results, white cells are for inputting data.
Three separate scenarios can be explored.
The idea is you specify:
1) Battery Capacity and its initial state of charge
2) The period in hours over which the calculations are made
3) The current consumed by each item and proportion of an hour that it operates (eg. Fridge running @ 4 Amps 30mins per hour)
4) Average charge rate (say, from solar panel)
Using this data, the total energy consumption and state of charge of battery at the end of the scenario period.

I'm happy to email the spreadsheet to anyone - just pm me.
regards,
Allan

I have been using the Century marine range battery from Super cheap auto and found them excellent value and reliable. I have a combination of a deep cycle and starter, both Century. I read a million posts on lead acid vs gel vs lithium vs blah blah blah and just decided the lead acid was (for my needs) the way to go. SCA regularly has them on sale for up to 30% off. You probably pay a bit more for the 'marine' brand because they are blue rather than black.

I do not know or particularly understand the science but different batteries require different types of charge cycles. Might be worth reading up on this before you decide on your battery choice.

Ed

Just to clarify Jode5's reference to replacing both batteries at the same time with identical units, he is correct where this refers to 2 or more batteries that are connected in parallel.

But this doesn't apply to replacing separate house or starter batteries (unless they're both stuffed, or you got s good 2-for-1 deal). Sorry if it sounds like nit-picking, but it might confuse some of our posters/readers who aren't very elec-savvy.

Cheers, Graeme

I've done what Datawiz has [power consumption chart] in the past after converting all lights to LED.

We were then surprised to find that the highest consumer was the lights on the switch boards [ex WW]
So we made up a new one without lights! Saved heaps!

As you know, lead acid batteries are charged by voltage control
chargers, it is quite OK to connect any capacity or manufacture
battery for parallel charging. Each battery takes as many amps as
it needs without affecting others.

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Charriot said..
As you know, lead acid batteries are charged by voltage control
chargers, it is quite OK to connect any capacity or manufacture
battery for parallel charging. Each battery takes as many amps as
it needs without affecting others.

Hay Charriot
We will just have to disagree on this one. I've had a fair bit to do with this on boats with big banks of batteries that combine different types and voltage batteries on one boat eg. 6 x 160Ahr 12 volt parallel house, 1 x 90Ahr start plus 2 x 24volt thruster batteries all needing to be charged from the same sources.
Charge one battery from a charger,no problems. Charge two batteries from a charger, most people get away with it with reduced battery life. Keep adding batteries to the bank and the problem just get bigger. Remember one odd battery in the bank can confuse your modern smart charger.
i'm like You 44 years in the Electrical industry.

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Toyboata said..
Graeme you've given me a days work in that post! I've been scouring gumtree for a decent house battery.. Plenty there just need to decide what I need. $120 for 120AH and $130 for a new 100W solar panel is looking good! I'll chec my regulator is MPPT.. Seems to do the trick!

Jode5 as much as I'd love an Engel and top of the line matching batteries... Maybe next year $$$$$

Try this one

www.ebay.com.au/itm/30L-35L-Portable-Freezer-12V-24V-240V-Camping-Car-Boating-Caravan-Bar-Fridge/272980868078

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nswsailor said..

Toyboata said..
Graeme you've given me a days work in that post! I've been scouring gumtree for a decent house battery.. Plenty there just need to decide what I need. $120 for 120AH and $130 for a new 100W solar panel is looking good! I'll chec my regulator is MPPT.. Seems to do the trick!

Jode5 as much as I'd love an Engel and top of the line matching batteries... Maybe next year $$$$$

Try this one

www.ebay.com.au/itm/30L-35L-Portable-Freezer-12V-24V-240V-Camping-Car-Boating-Caravan-Bar-Fridge/272980868078

Is that Kenner unit, the one you got NSW?

$337 for the cheapie vs about $700 for a CF35 or $900 for a CFX35, the cheapie is tempting???

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BlueMoon said..

Is that Kenner unit, the one you got NSW?

$337 for the cheapie vs about $700 for a CF35 or $900 for a CFX35, the cheapie is tempting???

Yep. actually $303 with discount, but in the end it came down to size and the Kenner beat the others hands down with the same sort of compressor. Once I get a new battery bank and use it I'll report back.

I had pretty much decided on a Dometic CFX40 from researching, but the cheapies are interesting & with a $500 saving as a bonus.
Can you plug it in to 240v to test it?
cheers

Update on the battery purchase... My existing starter battery which is in good working order is a Remco RM12 100AH which I thought was dual purpose but could well be deep cycle...

New house battery will be a Remco 100AH Deep Cycle battery (RM12-100DC-M8) to match the starter.. Bit more dosh than i would have liked to spend but at least I'm getting 10 years worth of battery for my money!

Next problem to solve is solar upgrade!

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BlueMoon said..
I had pretty much decided on a Dometic CFX40 from researching, but the cheapies are interesting & with a $500 saving as a bonus.
Can you plug it in to 240v to test it?
cheers

Yep, brought it down to -9 in 1/2 hour on 240 when empty

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Toyboata said..
Update on the battery purchase... My existing starter battery which is in good working order is a Remco RM12 100AH which I thought was dual purpose but could well be deep cycle...

New house battery will be a Remco 100AH Deep Cycle battery (RM12-100DC-M8) to match the starter.. Bit more dosh than i would have liked to spend but at least I'm getting 10 years worth of battery for my money!

Next problem to solve is solar upgrade!

Good discussion.
Just a little advise, prior to paralleling your new battery and your existing battery, give your existing battery a good charge with a good smart charger and then do the same with the new battery. This same procedure should be done say every four months, especially if you are relying on solar to keep your batteries topped up while not using your boat. By doing this you, will get the best life out of your batteries.

Both fully charged. I run the diesel weekly so that'll keep then topped up nicely.

Any thoughts on a 100W solar panel? I was thinking about leaving the 20watt panel in place over the Stern and getting a flexible panel for use when cruising.. I'd throw it on the cabin top and only use it for short periods... Any links to proven cheapies?

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Datawiz said..
Estimating energy consumption, charging and battery size requirements is not easy. As part of an electrical upgrade of my boat, I designed a useful spreadsheet.
Unfortunately, spreadsheet files can't be uploaded to this forum, but the pic below might show what it does.
Red cells are calculated results, white cells are for inputting data.
Three separate scenarios can be explored.
The idea is you specify:
1) Battery Capacity and its initial state of charge
2) The period in hours over which the calculations are made
3) The current consumed by each item and proportion of an hour that it operates (eg. Fridge running @ 4 Amps 30mins per hour)
4) Average charge rate (say, from solar panel)
Using this data, the total energy consumption and state of charge of battery at the end of the scenario period.

I'm happy to email the spreadsheet to anyone - just pm me.
regards,
Allan

I second this approach of compiling a spreadsheet (or table) so you can track your different usage scenarios. In the off-grid energy industry they call it a "Load Demand Survey" - and boats are about off-grid as you get

I'm also a big believer in the more PV panels, the merrier. Arriba has 200W of PV and frankly it is not enough when I have a full crew all wanting to charge their various gadgets (or just plain ol' cloudy weather). The new USB-C phones and tablets can easily draw 10W or more when charging!

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scruzin said..
I'm also a big believer in the more PV panels, the merrier. Arriba has 200W of PV and frankly it is not enough when I have a full crew all wanting to charge their various gadgets (or just plain ol' cloudy weather). The new USB-C phones and tablets can easily draw 10W or more when charging!

+1 on that!!