Batteries

[paulstoke1975]

Another power question,

 

i am starting to realise its not going to be as simple as plug all my stuff in and sale off into the sunset

 

i been looking at boats today and some have 1 starter battery an 1 leisure battery,

others have 1 starter and 3 leisure,

obviously more is better but what is required when adding extra batteries?

 

how do they connect to the current set-up on a boat?

 

is there a cable kit available ?

 

and would anything else need to be upgraded to take the extra batteries ?

 

 

 

 

[Paul C]

They are connected in parallel, but be aware of the right place to take the power and negative leads from - opposite corners on a 2 or 3 battery bank (see smartgauge website for picture and explanation)

 

You need

 

1) the space for them

2) the cables to connect them

3) a way of clamping them down securely (or otherwise to satisfy the BSS requirements)

4) something to cover the terminals against accidental shorts by dropped tools (again, for BSS)

UPDATE: link here: http://www.smartgauge.co.uk/batt_con.html

[Ex- Member]

Another power question,

 

i am starting to realise its not going to be as simple as plug all my stuff in and sale off into the sunset

 

i been looking at boats today and some have 1 starter battery an 1 leisure battery,

others have 1 starter and 3 leisure,

obviously more is better but what is required when adding extra batteries?

 

how do they connect to the current set-up on a boat?

 

is there a cable kit available ?

 

and would anything else need to be upgraded to take the extra batteries ?

 

 

 

 

 

The size of your battery bank should be determined mainly by your power usage. It's all a balance at the end of the day, If you feel you can live on 12v alone a couple of batteries might well suffice, inverters and 240v equipment then 3+ depending on amount. There are calculators available to assess usage.

 

Also if upgrading, adding batteries to existing batteries in not advised, especially if the existing batteries are old. Ideally an all new bank is the best way forward wired in the way Paulc has mentioned.

[Alan de Enfield]

Its all interlinked

 

How much power you use - the size (number) of batteries - the ability to put the power back

 

Its no use havng a big battery bank if you only have a weedy 30 amp alternator, remember the 'guide' that it will take twice as long to put it back in then it took to use it.

 

If you use 30 amps and have a 30 amp alternator it will take 2 hours+ to replace it (because your alternator will not be putting out 30 amps, and as the battery 'fills up' it gets harder, and harder to 'push' the electrikery in).

[matty40s]

You seem to be viewing boats before knowing what you will need as a live aboard.

Write down how you will use the boat, where and if you will be moored and what facilities it has.

Also add your normal power usage.

Then work out what you need from a boat, or what you need to spend to get a not quite right boat suitable for you.....

 

Then start looking at boats again.

[Paul C]

If I were about to buy a liveaboard boat, I'd not worry too much about what batteries it currently has because sooner or later I'd upgrade to a decent sized bank of traction batteries eg Trojan T105s. I don't know, maybe 6 months out of the existing bank? So you could at least get onto the boat and get used to it, then do the upgrade when they die.

[b0atman]

Biggest problem is the ability to charge Batteries

Battery charger needs to be more than 10% of Battery total amperage .

Alternator have you only 1 or have you 1 for starter battery and 1 for domestic battery.

30 amp is going to restrict size of battery unless you are running engine for a long enough time

larger ones are obviously going to be better but depending on load engine will still need to be run regular .

Solar panels are the best answer (in my opinion) with an mppt controller.

[bottle]

Hi Paul

 

Others have answered your question but I will just add as an example what our boat, a continuously cruising, all electric (no gas), 60' narrowboat has.

 

6 X 110 amp,hr deep cycle (not leisure) AGM batteries wired in series, parallel giving a bank of 330 amp,hr @24v

 

2 X start batteries, one engine , one generator

 

7Kw generator, diesel cocooned and as big as the propulsion engine physical not cc

 

Alternator 12v 50 amp for start battery

 

Alternator 24v 80 amp for domestics

 

4 X 100 watts solar panels

 

1 x Victron combi (inverter and charger) 24v. 2Kva. 50amp

 

Some would say we are getting towards the extreme end but it is what we need to be able to lead the lifestyle we want.

 

There are others out there with even more power.

 

It will all depend on your lifestyle and how you wish the boat to deliver it.

Edited May 18, 2014 by bottle

[Clifford]

The basics you need to get right (by calculating your planned energy usage):

 

 

- how many batteries you need : too few and your lights and telly will go off at 9pm and you will flatten your batteries and knacker them : too many and they will not get charged properly and you will knacker them.

- the size of your alternator(s), 230v battery charger, solar panels, and (possibly) generator : too small and you will again flatten your batteries every night and knacker them.

- the size of your inverter : too small and you won't have enough AC to run your mains-powered stuff.

- the thickness of the cables connecting your batteries to each other anbd everything else : too thin and you will lose voltage and power heating your cables up (and possibly melting them).

 

None of this need be too daunting with help from this forum. But you will first need to read up on Volts, Ohms, Amps, and Watts - and Ohm's law. Otherwise you won't really understand what anyone is saying.

 

When you understand clearly the very different consequences of connecting stuff in series as opposed to parallel, and the fundamental difference between Amps and AmpHours (and why you should ignore the advice of anyone who mentions amps/hr - joking, folks), it will all start to make sense quite quickly.

Edited May 20, 2014 by Clifford