I may have wired this wrong...

[seapop]

Just installed a new Xantrex Freedom 806-1840 HF 1800 Inverter/Charger, but I'm wondering if I did it right.

I have two large 12 volt deep cycle house batteries, wired in parallel, and then a separate starter battery, "sealed" type.

There is only one + positive post on the charger so I attached both wire cables to the charger (one goes to house batt and the other to starter batt).

This is the way the previous older charger was connected also.

Is this a proper hookup? Or should I keep both different battery sets isolated from each other?
Is this dangerous? Or just terribly inefficient?

thanks for any suggestions

[billknny]

Originally Posted by seapop

Just installed a new Xantrex Freedom 806-1840 HF 1800 Inverter/Charger, but I'm wondering if I did it right.

I have two large 12 volt deep cycle house batteries, wired in parallel, and then a separate starter battery, "sealed" type.

There is only one + positive post on the charger so I attached both wire cables to the charger (one goes to house batt and the other to starter batt).

This is the way the previous older charger was connected also.

Is this a proper hookup? Or should I keep both different battery sets isolated from each other?
Is this dangerous? Or just terribly inefficient?

thanks for any suggestions

What you did was connect the positive terminals of the house and starter battery together... making them into ONE bank connected all in parallel. They are no longer separate, and it sounds like they never were.

When ever you draw from one, you draw from both.

This is such a basic mistake, I'd suggest you have a competent marine electrician review all your wiring.

[Privilege]

That's not the correct way to do it...by connecting them together at the charger, you are effectively paralleling the two banks which will cause all sorts of problems, especially if they are different types.

The best and easier solution IMHO is to leave the charger charging the house bank and then put a Voltage Sensitive Relay (VSR) between the two banks. It's simple to install, is maintenance free and a foolproof way of getting both banks charged.

Your A/C charger goes to your house bank and your alternator goes to your starting battery.

[smac999]

Your old charger likly had 2 outputs... one for each bank.

What you did was screw up really bad. Possibly leaving yiu dead in the water with a dead engine battery. As above. Stop screwing around and have someone look at it. If yiu made that mistake on the dc. I'm scared to see what you did when adding the ac pass through wiring. .

[Privilege]

Seapop, don't worry about negative comments. There's loads of really knowledgeable sailors on this site and most all of them are happy to share their wisdom.

[hellosailor]

You can debate whether to connect the alternator and the charger to different banks, or to combine them. Personally I'd lead them both to the starter battery (which wants to be recharged quickly but needs very little power) and then connect the starting battery with a West/Yandina Battery Combiner. That's a small black box which waits until the first (i.e. starter) battery has gotten up to full voltage, and then it combines a second battery (house bank) to share the charging sources. As soon as the charging sources are stopped, voltage drops below 13.6~ again and the combiner opens up, isolating the two batteries again.
The Yandina combiner was originally basically a relay, the Hellroarer and EchoCharger and various other "combiners" are also on the market today. Figure somewhere between $100-200 depending on the amp capacity rating of the one you buy.
Then your only problem might be that a "maintenance free" battery might not want the same charging voltages as your house bank. Or, the two might be far enough apart that there's a voltage drop in the cables, beware for that.
If your alternator has a "three wire" setup, with a dedicated battery voltage sense lead, make sure that is hooked up properly too. If the two batteries need or get different voltage, the sense lead can only be tied to one, leaving the other to charge improperly.
If you do get an electrician...try to find one who'll explain what they're doing and why they are doing it.

[seapop]

First I want to say thanks the for the "positive"comments from most of you, and the good advice.
When I when I was hooking it up for the first time I was a bit suspicious that one output Port from the charger inverter would be going to two different battery Banks, including two different types of batteries. I did it that way because the previous charger did it the same way and I feel now that that was done incorrectly.. my decision now is to put a smaller dedicated charger on the starter battery and leave the house batteries on the charger inverter. In retrospect, I think hooking both sets of batteries to one output is less dangerous than it is just inefficient. It would cause all batteries to be charged and maintained only to the level of the status of one of them and not for the other. Which would be inefficient at best. By the way the AC hookups are fine as well as the past through and the inverter function. Thanks again for all the help.

[waterman46]

You can do this yourself - don't be discouraged by those who post otherwise. Get a book and read the part about battery charging options with multiple banks, before proceeding.

You do need to prevent drawing down your starting battery when using any 12V equipment on your boat. Several methods have been suggested. But, a caution on battery combiners/isolators that use mechanical relays. My experience has been that mechanical relays don't have a long lifespan when used at the high currents experienced during charging a discharged house battery bank. They start out life as with a negligible low voltage drop, but then over time they become more and more resistive at high current. There are solid state devices which have initial tenths of volt drop, but they do not slowly degrade with time and use.

[Cadence]

Forget that rude post. The poster should get a life.

[tarian]

Hey doing the same thing with my batteries at the moment
I am putting the main battery charger on the house bank and using a VSR of of the alternator for the starter , keep you banks separate a decent VSR will cost very little and is easy to install and safe to the batteries remember your starter batteries only need to start your engine , so they will get charged quickly with the engine running so no major issues
good luck