Two alternators - combining them

egantsea · Veteran Member

Two alternators - combining them

Farron Peffer · Veteran Member

Hello Chip,

Congratulations on the new engine!

The battery switches that you describe are paralleling switches that more or less combine your batteries into one large bank.

This is good as it allows for your alternators to charge all the batteries at once.

It is bad because it causes your individual batteries to attempt to act as one large single battery.

The battery with the best charge will be drawn down by the battery with the least charge. The battery with the most charge will tell the alternators to power down and thus not allow the lesser charged batteries to get a full charge.

For multi battery/multi alternator systems we have found the ADVERC battery controller to be a very nice system for doing a simple job in an elegant way.

The ADVERC system measures the battery voltage and controls the alternator output to give the best and fastest charge to each battery. Isolators allow the system to work with more then one battery and more then one alternator. Because the system measures battery voltage and not alternator voltage the isolators do not limit the charge.

The ADVERC system is not an extrnal regulator, it is a very robust and simple controller that "piggy backs" onto the internal regulator of the alternator. This allows you to have a degree of redundancy in the system. If the controller were to have a failure, the ADVERC system can be unplugged and you can then operate on the standard internal regulator.

As I say, it is a simple system but a bit too involved for me to cover all the potential applications in this forum. The system is just to flexible!

If you will e-mail me a request I will be happy to forward to you (or anyone) a white paper that describes the system and applications.

egantsea · Veteran Member

OK thank you for the information. Luckily for me I have not installed the switch yet so i think I can bring it back if needed. I was going to just use it for emergency jumping the starting battery with the house bank. Another switch may be better after I read about the system your mentioned.

I will read up on the system you suggested then will probably have more questions

http://www.adverc.co.uk/batterymanagement/split-charging-systems

-- Edited by egantsea on Monday 7th of February 2011 02:42:19 PM

egantsea · Veteran Member

Another quick question.

If I wanted to use the battery switch That I have that combines the two batterie banks for emergency starting will it hurt the controller when we combine them for emergency starting then switch back to two seperate banks when the engine starts?

Will it hurt the current setup with two alternators one on each bank our would it hurt them when we install the ADVERC BM system if they were combined for emergency starting then switched back to two separate banks?

The switch is like using jumper cables. We would only connect the two battery banks if the starting battery was dead, then switch back to the starting battery.
Thanks,
Chip

-- Edited by egantsea on Monday 7th of February 2011 04:04:40 PM

Farron Peffer · Veteran Member

Hello Chip,

Yes, you can use your switch to combine the battery banks. It will not hurt the alternators but it will not allow the alternators to work to their potential.

Isolating the alternator outputs would allow you to get the best charging efficiency.

A drawing of an ADVERC installation for two alternators is attached. This design charges both batteries from both alternators. You could add a battery selector switch to this installation with out a problem.

egantsea · Veteran Member

Thanks,
We plan on installing the ADVERC controller but it may take some months to get there. In that time we will just use the switch in case of an emergency.
Thanks for your help,
Chip
s/v Elegant'sea IF36-B #29
http://elegantsea.blogspot.com/