Is a Charge Splitter the Way to Go ?

[crazyhorse77]

Does any one know how charge splitters work? To give you a back ground on our setup;

A 55amp alternator goes into a Durite 90amp charging splitter which feeds the battery for the starter motor and a 200Amp deep cycle battery bank for domestics.

The main questions are
1. Would the Durite unit equally split the charging load or dynamically share the load based on demand? So if the domestic battery bank was at 50% charge would nearly all the available charge go to the domestic battery bank?
2. How much would we benefit from installing a multi step regulator (my understanding is the alternator is a regulated to a single voltage of around 13V). If so any advice on affordable models?
3. Would it be worth our while to upgrade to a 90 Amp alternator and not installing a multi step voltage regulator?

Some info on the charge splitter below
http://www.durite.co.uk/pdf/5/05.16%...r%20device.pdf

Hope you hear from you

cheers

Tia and Jarvis

[Pete7]

Folks, you might want to have a look at the Sterling Alternator to the Battery charger which supplies a standard voltage to the start battery and a higher voltage to the house bank.

Sterling Power Products: Alternator to Battery Charger

Pete

[DeepFrz]

Balmar DuoCharge or Xantrex EchoCharge are a couple.

duo-charge
Automatic Charging Relays - Blue Sea Systems
Battery Chargers | Auxiliary Battery Charger | Xantrex

If you search the forum for Duo Charge or Echo Charge or battery combiners you will find lots of info on how they work.

[crazyhorse77]

How much would we benefit from installing a multi step regulator? Would it be better to upgrade the alternator or install a multistep regulator to the existing 55amp alternator?

cheers

[Pete7]

200 amps for a house bank is quite small on a 35ft Trident. Some thoughts.

1. What's wrong with the current set up, are you struggling to charge the house bank?

2. Do you plan any other changes, like more batteries?

3. If the current system works and keeps you batteries charged is there any need to change at the moment/

Pete

[crazyhorse77]

Cheers Pete for your reply,

We have and extra 100A battery of the same type and make we are thinking of adding later.

1. Ans. To be honest we only just got the boat a few months back and have been updating it ready for live aboard when we set sail for 18 months. From what i have been reading I currently think the alternator will struggle with power requirements

2. Ans. Yes and extra 100A

3. Ans. No real life tests yet

I am not sure if the multi step regulator makes as much diference as they say. what do you think?
cheers

[Pete7]

Do nothing for the moment apart from add the other battery to the house bank or it will slowly die and be useless.

You then need to find out how many amp hours you need each day and from there what you will do about charging to replace those amp hours. You need to consider whilst on passage (sailing) in harbour and at anchor. The solutions are wind, solar and engine charging or hook up in a marina. You will also need to properly size a battery bank so it doesn't run below 50%

Until you have worked out what to do about the above you could easily waste hard earned cash and regret it later. Certainly running the engine to charge the batteries with no load won't do it any good.

All the information is on this forum. Since you are not going sailing for the next few months, certainly not in the North Atlantic, it would be worth researching in the electrics forum.

Pete

[Pblais]

A multistage regualtor is a good idea for the house bank. I would not suggest a dual charging alternator or regualtor. You don't need that much. A combiner would do the job just fine and a isolator diode would be dirt cheap if you compensated the voltage drop.

The muti stage regulator is going to add more amps when the house bank is low than when it is high. This is the charge acceptance based on how fiull the battery is based on the type of battery. Whan it gets near full you can not add a lot of amps. The combiner will steal from the house bank as it charges until it reaches full charge voltage. The starting battery should recharge quite quickly so it does not need over charging. The dual chargers are better since both are regulated but you just don't have that much battery to charge and they cost a lot more.

I prefer an external regulator because it can be smarter and the alternator can be dumber. The regualtor might last longer than the alternator though mine didn't. You save a little money on the one but pay a little more on the other.

Your house bank will represent a big $$ investment and you want to be able to charge it as fast and as safe as it is to do so. You need to get a feel for how many amps you will burn between charges. Ideally the house bank never goes below 50% capacity and then you recharge it 100% for maximum lifespan (best investment).

Sometimes it really is all about the money. Deep cycle batteries are what you need to live on and they cost a lot. For a fridge with lights and basic gadgets 400 amp hours capacity is a good-sized bank since you only use half ideally but could use more if required. That is the way real life is sometimes. In the end if you make the bank too big you'll never recharge it properly and it will die sooner from under charging. If you make it too small then you'll discharge below 50% on a regular basis and the batteries won't last as long. So how consistent can you be?

It all is perfect if you recharge everyday the amount you used the day before. You can do it any way that works by using less power (smaller bank) or making more charge (bigger bank). The regulator determines how fast you can do it given the largest alternator they make. The deal is if you oversize the bank the last 10% is a killer since it takes a lot longer. 10% of a large bank = can't get there normally. It's a case where too big a bank can be the worst alternative.

If you search around there is a LOT of details about electrical systems on the forum in many threads.