Alternator charging question

[peters.carl]

This should be a fairly basic question for some so excuse my ignorance. I have a 26ft keelboat and am installing a Beta16 engine. I will have two battery banks, a start battery and house battery. Both batteries to be charged off the one alternator. At the moment the current engine charges the batteries through a splitter diode. We only do weekend cruising and dont have "huge" battery demands.
Questions:
1. What would be the "best" way to charge the different batteries. I know ample and balmar do some smart regulators. Which would you recommend? I dont want to use a 1-2-both switch because I'm hopeless/lazy/would forget. Preferably a relay system.
2. Does anyone know what "size" start battery I should get for the Beta 16 engine?

Many thanks.

 

[VicS]

This should be a fairly basic question for some so excuse my ignorance. I have a 26ft keelboat and am installing a Beta16 engine. I will have two battery banks, a start battery and house battery. Both batteries to be charged off the one alternator. At the moment the current engine charges the batteries through a splitter diode. We only do weekend cruising and dont have "huge" battery demands.
Questions:
1. What would be the "best" way to charge the different batteries. I know ample and balmar do some smart regulators. Which would you recommend? I dont want to use a 1-2-both switch because I'm hopeless/lazy/would forget. Preferably a relay system.
2. Does anyone know what "size" start battery I should get for the Beta 16 engine?

Many thanks.

You could still charge via a diode splitter but you really need an alternator that is battery sensed or you will not reach the "normal" fully charged state due to the volts drop across the diode.

You could use a VSR rather than a diode splitter to avoid the volts drop issue. I think this would be my choice.

You could fit a Sterling advanced regulator together with a diode splitter to get even higher states of charge but the standard alternator will need a small modification.

You could fit a Sterling "Alternator to battery charger". That will give enhanced charging of the house battery and simultaneous standard charging of the starter battery. Being an "Add on" device no alternator modification is necessary.

Is there no recommendation on battery size in the Beta literature? **
A CCA recommendation would be nice but don't be surprised by an Ah capacity recommendation


** there is. It's 40Ah minimum!
Go for 60 or 70 Ah ie a medium sized car starter battery

 

[William_H]

Battery charging

I think the standard Beta engine will have an alternator set up for one battery.
The easiest solution is to wire up the battery as per Beta diagrams. Then move all the domestic loads to the second battery via a separate isolation switch. As already said connect the positives of the 2 batteries together via voltage sensing relay. Either buy a VSR with the ability to overide and carry heavy start current as a jump start battery if engine battery is dead. or carry a jump start lead or add another emergency jump start switch. It is most likely that the diodes used in the old system will not give battery charge. good luck olewill

 

[alahol2]

If it's of any interest this is the system I installed on our Beta 13hp engine. Money was tight and a VSR was too expensive so this was a half-way house. Had it for the last 5 or 6 seasons and it has worked well so far.

I should have mentioned that the circuit was gratefully received from another forumite on here (can't remeber who ).

 

[VicS]

If it's of any interest this is the system I installed on our Beta 13hp engine. Money was tight and a VSR was too expensive so this was a half-way house. Had it for the last 5 or 6 seasons and it has worked well so far.

I should have mentioned that the circuit was gratefully received from another forumite on here (can't remeber who ).

With that system won't there be some current drawn through the relay contacts from the house battery by the starter.

I'd be afraid that the relay contacts and wiring could be overloaded especially if the starter battery was not fully charged or getting past its best.

 

[alahol2]

With that system won't there be some current drawn through the relay contacts from the house battery by the starter.

I'd be afraid that the relay contacts and wiring could be overloaded especially if the starter battery was not fully charged or getting past its best.

It did worry me initially but it doesnt seem to be a problem. As I said, I've been using it for several years and it's still going fine. I've run the starter for maybe 15-20 seconds at a time when bleeding the fuel system and nothing seems to overheat.

 

[lw395]

Depending on what GPS you have, the house battery may be pulled low enough in voltage to crash the GPS when you start the engine.
This is a pain in the neck, especially when firing up the engine at an awkward point in pilotage.

I've found relays to be unreliable in boats.
IMHO you either want a fully automatic system, or a simple manual switching system with a foolproof set of instructions and the discipline to use it properly.
At some point it can be useful for other people to understand the system you have!

I would recommend a battery-sensed regulator and split charging diodes. Preferably one with a soft start function as otherwise alternator belts wear badly in my limited experience.
If you are using batteries that cannot be topped up, you need to more careful about over charging than if you are using olde worlde truck batteries.

 

[VicS]

It did worry me initially but it doesnt seem to be a problem. As I said, I've been using it for several years and it's still going fine. I've run the starter for maybe 15-20 seconds at a time when bleeding the fuel system and nothing seems to overheat.

If there was a problem like this or if a drop in house battery volts caused instruments to crash as highlighted above it could perhaps be be solved by fitting an ignition switch with an accessories position which is de-powered during cranking and supplying the relay from this.

 

[nigelmercier]

You could use a VSR rather than a diode splitter to avoid the volts drop issue. I think this would be my choice...

My choice as well, but with a smart charger like the Balmar there is no volt drop problem.

 

[ianj99]

My solution was to use a 100amp sealed contactor from RSWWW and power it from the aux out on the alternator.

This means the contacts only close and charge the house battery when the engine is running.

I too recommend a Sterling Digital regulator which will ensure the batteries receive 100% charge (given enough charging time).

I

 

[VicS]

My solution was to use a 100amp sealed contactor from RSWWW and power it from the aux out on the alternator.

This means the contacts only close and charge the house battery when the engine is running.

I too recommend a Sterling Digital regulator which will ensure the batteries receive 100% charge (given enough charging time).

I

But in the OP's case is any form of "smart charger" or "advanced" alternator regulator really worth the expense and added complication.

He says, "We only do weekend cruising and dont have "huge" battery demands."

It would seem to me that all that is necessary to overcome his hopelessness, laziness and forgetfulness is a VSR, or other relay, controlled system.

 

[ianj99]

But in the OP's case is any form of "smart charger" or "advanced" alternator regulator really worth the expense and added complication.

He says, "We only do weekend cruising and dont have "huge" battery demands."

It would seem to me that all that is necessary to overcome his hopelessness, laziness and forgetfulness is a VSR, or other relay, controlled system.

I really meant to say, if you want a digital regulator, then I would recommend a Sterling over other makes.

I

 

[BabaYaga]

This should be a fairly basic question for some so excuse my ignorance. I have a 26ft keelboat and am installing a Beta16 engine. I will have two battery banks, a start battery and house battery. Both batteries to be charged off the one alternator. At the moment the current engine charges the batteries through a splitter diode. We only do weekend cruising and dont have "huge" battery demands.
Questions:
1. What would be the "best" way to charge the different batteries. I know ample and balmar do some smart regulators. Which would you recommend? I dont want to use a 1-2-both switch because I'm hopeless/lazy/would forget. Preferably a relay system.
2. Does anyone know what "size" start battery I should get for the Beta 16 engine?

1. It says in the engine manual that the standard 40 A alternator is battery sensed (as opposed to the optional 70 A one). It is not clear to me exactly how the sensing wire should be connected to the battery, but likely Beta can advise. There is also a wiring diagram for diodes in the manual.
If this works out, your first bet could well be to keep the splitting diodes as the internal voltage regulator will sense and compensate for the voltage drop.
2. The recommendation is a battery of 350 - 400 CCA, typically 35 - 40 AH, as a minimum.

 

[peters.carl]

I really meant to say, if you want a digital regulator, then I would recommend a Sterling over other makes.

I

Why is this? What are the benefits of the sterling over this for example:
http://www.balmar.net/duo-charge.html

Would this be something worth looking at or would it mean that the house battery never quite gets a "good" charge?
My problem is that the house and start batteries will be two different batteries. One a deep cycle the other a start. Therefore would the 'Sterling' system be the best? Or is a series regulator like the one above a better option?

 

[mitiempo]

The Balmar DuoCharge is a charge follower - when a charge voltage is sensed it passes up to 30 amps to the downstream battery, usually the start battery. It works with any charge source but is a one way device. Charging sources go directly to the house bank. It can be set for different battery technologies -flooded, gel, or agm. It is similar to the Echo Charge but has a 30 amp limit to the Echo's 15 amps.

 

[ianj99]

Why is this? What are the benefits of the sterling over this for example:
http://www.balmar.net/duo-charge.html

Would this be something worth looking at or would it mean that the house battery never quite gets a "good" charge?
My problem is that the house and start batteries will be two different batteries. One a deep cycle the other a start. Therefore would the 'Sterling' system be the best? Or is a series regulator like the one above a better option?

You could use this in conjuction with the Sterling, but not instead of it if you really want to charge batteries to 100% ( as near as).

I use a Sterling Mains charger and digital regulator on the boat, (twin identical Banner batteries ) and on the camper, another Sterling digital regulator but with different battery types. (standard LA engine battery and Optima Blue top van battery).

The regulators sense the house / van batteries and the engine batteries are taken care of without any problems.
I use split charge relays (100a contactors not automotive relays in fact) rather than diode splitters, the relays being driven from the alternators aux output so only activate when the engine is running.

Ian

 

[mitiempo]

You could use this in conjuction with the Sterling, but not instead of it if you really want to charge batteries to 100% ( as near as).

Ian

As long as the alternator regulator is set at 14.4 volts the batteries will be fully charged in their own time. After about 85% state of charge their internal resistance will limit the current they will accept - this applies to flooded, agm, or gel batteries - and the last 15% takes a long time. The only way to change this is to increase the voltage which leads to gassing and higher maintenance of the batteries.

The DuoCharge from Balmar as well as the Echo Charge from Xantrex both will fully charge the batteries as long as the voltage regulator is at 14.4 or close to it. If the alternator is a much older one and set at 13.8 volts the batteries will become fully charged eventually, but it will take a long, long time.

 

[Allan]

It did worry me initially but it doesnt seem to be a problem. As I said, I've been using it for several years and it's still going fine. I've run the starter for maybe 15-20 seconds at a time when bleeding the fuel system and nothing seems to overheat.

My system (Beta) is similar but has no SW3. It seems to me to be potentially more reliable if the risk of large currents through the relay contacts are taken away. Having SW3 still gives the option of using the domestic battery to help with starting, I may add one to my system.
I looked at the drawing and thought the same as Vic, I still can't understand why the relay is not fed from the other side of the charge light. I would be interested to hear the reason.
Allan

 

[mchancox]

Keep it simple. For easy weekend cruising go for a VSR. It will engage both batteries when the engine is running and will disengage when it has stopped. See how you get on with that before you spend more money on some extra gadget that you might not need.

Mike Hancox.
MCH Marine Electrics.

 

[mitiempo]

I agree - either a VSR or an Echo Charge will do the job simply and effectively. Both about the same price when VSR fusing is figured in. Both simple 3 wire installations as well.