How many batteries?

[VicS]

I believe there is a better wiring diagram and method for multiple batteries in parallel?

Sorry, I cannot find it at moment. Probably in a discarded old PBO magazine.

It is part of one of the technical articles on the SmartGauge Electronics website



Because it consists of two pairs of parallel connected batteries this arrangement can be split between the two sides of the boat which Zoidberg will need to do

See SmartGauge Electronics - Homepage for the complete article and many others

 

[Neeves]

Don't forget that if you add another battery and later another....your electric demand increases to just beyond you ability to store or replace the amps (and any further amps). For this reality blame Parkinson

On more serious note - I recall reading that adding a new battery to older batteries is not good practice (or) it might be good practice if you manage the new and old). Similarly adding batteries of different sizes is also not good practice. Now it may be I misread, or forgot the detail - best ask someone with expertise.

If you plan long passages then your auto pilot will gobble stored power. If you hit bad weather your AP will be a critical item but will gobble amps even faster then normal. Long passages also mean Nav lights, instruments, radios and the AP all on - and no ability to recharge, because its dark and the moon is pretty useless for recharging (unless that towed generator enjoys decent boat speeds, average of 6 knots +.

I'd plan for poor weather and increase your ability to charge as well as the size of your storage (think Lithium) and a second towed generator - small yachts have very limited room for large solar displays.

Jonathan

 

[Refueler]

When I bought Anisette .... I noted that it had one 90 AH for start ... two 90 AH for domestics. Sailing her home (36hrs) - all was good ...

I had also noted that there was a 90 AH battery not connected sitting under the nav seat .. interesting. I assumed it was there 'just in case'.

Later I found out why ... the domestics power obviously the fridge and all nav gear / tillerpilot / cabin etc. I have no electric windlass or winches.

The charging setup - is the standard 2GM Yanmar alternator with solid state relay between battery banks. Plus the old probably worn out 100W solar panel on deck. Plus shore power.

On a longer trip and limited time on shore power - the domestic bank showed its true character ... it was tired and OK for short trips with shore power at end of trip ... but longer and relying on solar - it just could not keep up ... meaning that on the long leg home - engine had to started every few hours to maintain power to nav gear / tillerpilot.
Its plain that extra battery was there from such ....

I swapped out the worst domestic for that spare .. but it was not long before the problem re-appeared ... so now I have to replace both batterys and look at a new solar panel to solve this. I have a couple of portable folded panels as well - I can place when boats idle ... as extra.

 

[[70521]]

And how much usable capacity?
I'm told to start with 'How much do you need?' and get bogged down after navlights, domestic lights, basic instruments, VHF, AIS, VHF/FM, CD player, handheld charger, tablet charger, phone USB-C charger, autopilot.... et al. No radar, thrusters, powered winches, widescreen TV, Starlink, u/w status lights...

I'm happy enough to have 100Ah Optima AGM for Start, 2 x Optima 100Ah for 'domestics', a plain vanilla 70A alternator, 2 x 100W or more PV panels - and a legacy towed generator! Should I later want to fit more battery capacity - e.g. another 2 x 100Ah Optima jobs - how best should I arrange that...?

I have 390 Ah of AGMs (130*3) as a house bank or roughly 200Ah of usable power. I have a self imposed discharge limit of 150Ah as measured by Victron.

I've calculated that I can run the boat for over 24 hours with zero charging, but even in depths of a Cornish winter I was getting some charge from the solar kit.

Charging: My 200 watts of solar panel that should keep up with my daylight hours needs and an engine that is usually used at some point in any 24 hour period unless I am on a longer passage.

 

[[70521]]

It is part of one of the technical articles on the SmartGauge Electronics website

View attachment 194761

Because it consists of two pairs of parallel connected batteries this arrangement can be split between the two sides of the boat which Zoidberg will need to do

See SmartGauge Electronics - Homepage for the complete article and many others

An interesting diagram.

I was always taught to take the +ve off one end of the bank and the -ve off the other.

Would this form of wiring change that?

 

[zoidberg]

Thank you all, good sirs ( and/or sirettes )

For the avoidance of confusion/doubt/tangents I do have an Autohelm steering stick which could be brought into use now and then, but the main aid to my 'feet up with cold beer in hand' cruising is a well-regarded windvane Seafeather thingy.

And, speaking of 'cold beer in hand' I recall I have one of those motor-vanning 12V cold boxes somewhere which could be used to keep the beer in. It's got to go somewhere!

 

[Blueboatman]

I’m sure you are old school enough to adjust your lifestyle to what battery capacity the boat can carry.

2x110 was all I carried (plus doubled up engine/windlass batteries).
Nowadays all that weight would be put into loverly lithium..

I reckoned even with solar and wind gen, it was often a case of either the keel cooled fridge OR the a/p or movie night.

Which is why windvanes are so nice ( and a cabin oil lamp)
Go on, “ it’s only money ”.

You must be getting very close to splashing now?

 

[mrangry]

I believe there is a better wiring diagram and method for multiple batteries in parallel?

Sorry, I cannot find it at moment. Probably in a discarded old PBO magazine.

The diagram is indicative and what I have aboard, it simply shows battery cables are the same length and resistance which places an equal loading on each battery

 

[Neeves]

I’m sure you are old school enough to adjust your lifestyle to what battery capacity the boat can carry.

Many of us are old enough to have discarded the memories of camping in the 19 50's and 60's to enjoy gin and tonic with ice, though another option (in maybe a different climate, Sydney in June) is malt whisky at cabin temperature.

The latter needs no adjustment to lifestyle (nor a fridge).

Jonathan

 

[zoidberg]

I’m sure you are old school enough to adjust your lifestyle to what battery capacity the boat can carry.
.....windvanes are so nice ( and a cabin oil lamp)
You must be getting very close to splashing now?

Yupp!

And one problem is that the Highways Agency's/Highways England/National Highways' big project of rebuilding the A36 here has now been bumbling along - despite fire, flood and the occasional rare-bat-in-a-cave all disrupting progress for 11 months on what should have been a 3-month project. They won't have finished before mid-July.

I haven't been able to get a 'sufficient' boat-trailer and HIAB-equipped tractor unit in here since last August, due to lots of kit, holes and trenches blocking the road. This is the latest obstruction:

 

[Blueboatman]

Yupp!

And one problem is that the Highways Agency's/Highways England/National Highways' big project of rebuilding the A36 here has now been bumbling along - despite fire, flood and the occasional rare-bat-in-a-cave all disrupting progress for 11 months on what should have been a 3-month project. They won't have finished before mid-July.

I haven't been able to get a 'sufficient' boat-trailer and HIAB-equipped tractor unit in here since last August, due to lots of kit, holes and trenches blocking the road. This is the latest obstruction:

Blimey
That must be frustrating
Highways agencies ( and pothole fillers) are particularly disliked around here in East Sussex just now. In fact it’s heading to a public enquiry on one lost cause I think ..
Could you ask them to make access a tad easier whilst they’ve hit the machines all fired up ?That looks quite tight

 

[William_H]

Thank you all, good sirs ( and/or sirettes )

For the avoidance of confusion/doubt/tangents I do have an Autohelm steering stick which could be brought into use now and then, but the main aid to my 'feet up with cold beer in hand' cruising is a well-regarded windvane Seafeather thingy.

And, speaking of 'cold beer in hand' I recall I have one of those motor-vanning 12V cold boxes somewhere which could be used to keep the beer in. It's got to go somewhere!

Do avoid so called cold boxes (peltier effect coolers) (indicated by their ability to heat as well as cool) They just waste power and do very little.
On the battery question. Do not take too much notice of what other people have (and need) Your requirements will be particular to you and only experience will prove the need for a better power storage. ol'will