Charged up!

[Sirus]

Could someone help,have just come back from a two week holiday on the boat and found the batteries not up to the job.
Basically I would like to know the best way to opptimise power on board,at the moment I have two 120amp batteries charged from an 55amp alternator that only seems to be charging at just over 13volts because i'm on the river running just over 1ooo revs and no shore power.

Question 1 What is the max battery amps I can have.
2 Is it best to have a diode splitter.
3 Alternator boasters do they work.
4 Seems the batteries i've got are best suited for domestics,whats good battery for starting.
Thanks for helping me out..

 

[bobnewbury]

Afternoon Sirus.

1. I have it on the excellent authority of PVB that you can never have enough ampere hours. The problem with having lots of them is that it may take your alternator an awful long time to pour them into your batteries.

2. Diode splitters are useful, but they do result in a voltage drop. I can recommend investing in an Adverc battery management system. their support is second to none.

3. As far as I'm aware these work by boosting the field coil voltage and therefore the output voltage. I've heard some iffy stories about these if they're not strictly controlled - nicely boiled batteries etc.

4. Many domestic deep cycle batteries are not too good at delivering the very high currents needed for starting. You want bog standard starting batteries with as many CCA (cold cranking amps) as you can get.


I'm in the process of increasing my domestic battery bank to 500 AH. I'm doing it this weekend - I'll let you know how it goes if you're interested.

all the best,

 

[Sirus]

Thanks for the reply,I'd be very interested in how you get on.

 

[Gaffer]

I don't know much bout electrics, but I was told that the very best batteries to have for domestics are those specifically designed for electric fork lift trucks. Has anybody else heared similar ??

 

[Guest]

How about a solar panel and/or wind/water generator?

Regards,

Peter
http://www.mistressofmourne.com

 

[halcyon]

Your main problem is alternator rpm, you need to be 10,000 / 15,000 rpm alternator speed.
Can you alter one of the pullies ? you need to get the voltage up to 14.4 volts,

Alternate controllers are not worth looking at until you sort out the rpm problem, you may not have a problem then.

Diodes are a major no no, they will only loose you more power at the moment.

You can fit a starter battery, but it will only allow you to reduce battery size for the same crank amps, ie a large traction will give the same amps as a small starter.


What boat/engine installation?


Brian

 

[pvb]

Ideally...

Ideally, your solution would be as follows.

First, you need a separate starting battery and a separate domestic battery (or a bank of domestic batteries). The starting battery can be an ordinary car battery (most boat engines are fairly small compared with car engines). The domestic batteries should be "leisure" or "deep cycle" type.

To ensure that the starting battery isn't discharged in normal use, and to ensure that it's charged up as required, you either need a blocking diode or a battery combiner. In the UK, blocking diodes tend to be more common; in the US, battery combiners are more usually seen.

Whatever method you choose to separate your battery banks, you'll never recharge efficiently without a "smart" regulator. This will artificially increase the normal output of the alternator, to recharge your batteries faster. The better smart regulators (Adverc, etc) sense the charging voltage at the battery, and therefore compensate automatically for any voltage loss through a blocking diode.

The biggest problem with using batteries is discharging them. The more you discharge them, the shorter their life will be. Therefore it makes sense to have as large a domestic bank as possible, given the constraints of space. In your case, with a 55amp alternator, you could easily have a 400Ah domestic bank, and this would make recharging quicker, as well as increasing the life of your batteries.

 

[ParaHandy]

Agree & good advice (though are you sure that alternator rpm is 10,000?). Keep it simple.

Would think sirius might be better with a pair of (identical) 120amp hr marine batteries. No problem with starting current. There are slightly more expensive (£approx £90 each) batteries made by elecsol which claim to have much better cycle capability. Marine (or leisure as they're sometimes called) batteries can not take many charge/discharge cycles but these elecsol batteries claim significant improvement in that regard and have a 5 yr guarantee.......which is a lot longer than my current pair of 120amp batteries are going to survive for.

 

[pvb]

Wiring...

When you hook up a number of batteries to make a big bank, It helps to take the main positive and negative wires from opposite ends of the bank. In this way, any minor resistances in the connections tend to be cancelled out, and each battery gets the same charging voltage.

 

[Sirus]

The boat is a CHB or chan-wai trawler yacht with a single 120hp ford. These stirling alternator boasters are no good?

 

[halcyon]

Boosters will not increase output, they only control maximum output voltage, overcoming a volt drop problem (blocking diodes) or a low alternator regulator.

Is the alternator working?, you can have a diode fail that will only give a very low charge, if you increase rpm in neutral do you get a increase in voltage voltage?

If in doubt get your local Lucas agent to check it, until you know it's ok, it's not worth looking else were.

Brian

 

[Guest]

I think most of the foregoing is sound advice and the advice can be taken depending upon budget.

I would unhesitatingly recommend the purchase of an Adverc system- this is easy to fit, technical help is at hand from Adverc and it will transform byour charging system [safely] and it gets the best from your batteries.

This works well with a blocking diode because is checks the voltage at the battery - a blocking diode [without an Adverc] will prevent the batteries getting charged as it will only offer them 13.5v at best even if the alternator is superb. By checking BATTERY voltage the adverc system causes the alternator to raise voltage so that the maximum voltage at the battery is about 14.4v which is perfect.

Batteries - agree with advice set out above namely split your engine start and your domestics. If you can afford it get an Optima battery for engine starting. Small and nothing better

For domestics spend a little bit more than anonymous "Leisure" and but AC Delco Freedom or Elecsol or [a bit cheaper] Exide lorry batteries.

I have 55a alternator, Adverc, blocking diode, separate Optima starting battery, three 100AH AC Delco Freedom batteries. Adverc digital voltmeter hardwired up to monitor everything. All works perfectly and, importantly, you can see that it is working.

If you get an adverc read the instructions well so that you understand the principles; it reduces the battery voltage after about 20 minutes to check whats needed and then raises it again - you can hear the change in engine note as the alternator ACTUALLY puts out 55A.

Best wishes
Follow Adverc's advice and you will be happy

Andrew

 

[jfkal]

Get a Sterling regulator. They work fine. And or a solar panel with regulator to keep the batt. topped