West Marine Battery Combiner

[stormalong]

Originally Posted by BigAl.NZ

After reading over your post and some others I think this idea is sound.

1. Wire Delco starter alternator direct to starter batt.
2. Also swap out the existing combiner for the Blue Sea ML-ACR which has a manual override, so I can leave it normally off (each alt doing own batt), but if starter bank goes flat I can parallel them with this override switch.
3. If starter alternator fails all together the ML-ACR would allow me to charge both banks.

Sound reasonable?

You do not need to buy an additional combiner. Your existing combiner uses and external relay that is easily activated by a manual switch.

[BigAl.NZ]

Originally Posted by stormalong

You do not need to buy an additional combiner. Your existing combiner uses and external relay that is easily activated by a manual switch.

Yes, although a shiny new one with integrated switch does appeal!! I am a sucker for spending money on my boat

[BigAl.NZ]

I received a reply from the engineer who designed my combiner. Yandina who made it for West Marine for many years. Her reply was very informative and I repost it here for the benefit of anyone else in future. It also speaks volumes that I should be able to get such great support all these years later:

1. What is the point of the external ON/OFF switch between the two poles of the VSR?
The on/off override switch on Yandina and West Marine brand Combiners can be used to force the Combiner ON which connects the batteries together for emergency starting if the starting battery is low. It will act like jumper cable and after a few minutes allow the engine to be started.
The on/off override switch can also be used to force the Combiner to stay OFF. This may be used if a trickle charger or small solar charger is not putting out enough current to support the 1/8 amp that the Combiner uses when ON.
Yandina Combiners draw no current when OFF.

2. Why might the VSR be cycling through a process of switch on (13.3v) and off again at (14.1v) after an engine start
The Combiner makes sure that the alternator does not get overloaded. When the increased charging load gets connected it can exceed the capacity for which an alternator was designed and cause excessive heating. Under these conditions the Combiner will cycle off for a percentage of the time to allow the alternator to cool. As the level of charge improves the current gets less so the heating is less until eventually the Combiner stops providing cooling cycles.

3. Can multiple alternators with different profiles charge the same batteries?
The primary purpose of battery charging profiles is to protect the battery from damaging voltages and to force the charge in as fast as possible. A generic alternator such as found in automobiles has a "safe" profile that will not harm any batteries. But by limiting voltage it is also limiting the amount of current it can get into the battery so charging will take longer. The voltage at which lead acid batteries start to form bubbles in the electrolyte is about 14.2 volts. Although bubbles are advantageous in liquid electrolytes, they can displace electrolyte in a gel battery which may not get re-absorbed and reduce battery capacity. During the bulk stage of battery charging, the alternator can safely put out a higher voltage than 14.2 and force more current into the battery because there is voltage drop in the battery circuits and the voltage across the electrolytes will be much less than the alternator voltage. As that charge voltage increases the extra "forcing" voltage has to be reduced to protect the battery from over-voltage and this is what is happening in a multi stage regulator. The profile can be tailored to match the individual characteristics for maximum charging rate.

Using both your alternators is quite OK. It will mean that the total output of both alternators will less than the total of their individual capacities because subsequent to the bulk stage the regulators will be reducing output due to the higher voltage being introduced by the other alternator. Some references characterize this as the alternators "fighting" each other which is a misleading term. In fact they are both charging in later stages but charge rates are reduced by the effect of the other alternator. Depending on alternator sizes and batteries, adding a "generic" alternator to a "smart" alternator of equal size may not decrease charging time by 50% because the smart alternator will be able to put out a higher voltage which will make the dumb alternator think the battery is already charged and put out less current. Only during the early "bulk" stage will both alternators be putting out maximum.

4. Would there be any harm in wiring the Delco directly to the starter battery, and therefore if the combiner is off I know exactly what the Balmar is doing to just the house bank.
Sounds like an excellent idea

It is unlikely that the Delco is going too high on voltage. Old alternators dating back to the era of flooded cells would often have top voltages well above 15 volts that can damage gel style batteries. The "High Voltage" input on Yandina Combiners can be connected to the gel battery to limit voltage to 14.2 on the gel battery. If you find that the Delco is spending any time above 14.2 you could use that feature. However there is a downside - the smart charger will get above 14.2 volts when it is safe to force current into the battery and since it is on the house battery the Combiner would be shut off until the later stage when the voltage was back below 14.2 so charge current from the Delco would not reach the house bank while it was shut off. Everything would still get charged, it would just take longer.

It is common to hear a Combiner cycling for quite some time after charging has finished since the artificially high voltage left over from charging will remain on the batteries especially if there is any other charging source. Don't forget that the Combiners are bi-directional. With no load at all on the batteries that residual high voltage can take many hours to dissipate. It represents no additional battery capacity since it can't support any current. If one of the batteries is low, the combiner will try to charge it since it still has more than 13 volts but the sudden load will immediately drop the voltage to 12.8 and the Combiner drops out in about 20 seconds. With the load removed the voltage on the fully charged battery will float back up above 13 volts and the cycle will repeat.

[Andina Marie]

We (Yandina LLC) are the manufacturer of the West Marine Combiner.
I have not read any of the above responses.
The switching about once a minute is intentional.
The Yandina combiners are designed to protect the alternator from overload when charging a depleted battery that is demanding more current than the alternator can safely provide.
To protect the alternator the Combiner cycles off to provide cooling time for the alternator.
On each cycle the destination battery voltage will receive 1 to 2 amp-hours charge until it no longer represents an excessive load and the cooling cycles will then cease.
The duration of the cooling cycles can be from a minute or two to as much as 15 minutes or more depending on Alternator output, Battery size (amp-hours) and Existing loads on both batteries.
If the cycling continues excessively beyond the above you can try connecting the alternator to the house battery instead of the starting battery and let the Combiner top off the starting battery (it is bi-directional).
Your Combiner is 15 to 20 years old but still under our UNCONDITIONAL warranty if you determine it is not working correctly.

Ann-Marie Foster,
tech@yandina.com

[surf_km55]

Originally Posted by smac999

.....Also the solar should be direct to the house bank. Not after the switch. In your case just pick one battery......

BINGO.
Besides, the starter battery doesn't see enough cycling or self-discharge to warrant being included in the daily charging even if the batteries were of the same chemistry.


Didn't charging two different battery chemistries from a single charging profile sound an alarm [before experimenting]? Oops, sorry...I just saw the post where it wasn't even considered. Yikes. Be careful, Mate.

[john61ct]

Originally Posted by Andina Marie

We (Yandina LLC) are the manufacturer of the West Marine Combiner.

I have not read any of the above responses.

The switching about once a minute is intentional.

The Yandina combiners are designed to protect the alternator from overload when charging a depleted battery that is demanding more current than the alternator can safely provide.

To protect the alternator the Combiner cycles off to provide cooling time for the alternator.

On each cycle the destination battery voltage will receive 1 to 2 amp-hours charge until it no longer represents an excessive load and the cooling cycles will then cease.

The duration of the cooling cycles can be from a minute or two to as much as 15 minutes or more depending on Alternator output, Battery size (amp-hours) and Existing loads on both batteries.

If the cycling continues excessively beyond the above you can try connecting the alternator to the house battery instead of the starting battery and let the Combiner top off the starting battery (it is bi-directional).

Your Combiner is 15 to 20 years old but still under our UNCONDITIONAL warranty if you determine it is not working correctly.



Ann-Marie Foster,

tech@yandina.com

Thanks so much for that Ann-Marie!

Would you be willing to give a bit more detail on how your combiner determines when it is necessary to activate that current-limiting feature?

If for example the alternator is very large, and already has a sophisticated current-limiting external VR configured to prevent such overloading, would the engine runtime just be needlessly extended?

[YANDINA]

Originally Posted by john61ct

Thanks so much for that Ann-Marie!

Would you be willing to give a bit more detail on how your combiner determines when it is necessary to activate that current-limiting feature?

If for example the alternator is very large, and already has a sophisticated current-limiting external VR configured to prevent such overloading, would the engine runtime just be needlessly extended?

The current limiting ability is judged purely on the ability of the charging source to maintain voltage on the starting battery. If it cannot supply the current required by the destination battery(ies) it must be putting out its maximum.

So whatever the sophisticated profile is, it will not be throttled if it can do the job.