setting up a house battery and start battery

[shaeleblanc]

hey guys my boat currently has a single battery to start and run all the acc, i will be tossing some audio stuff in her shortly and i am going to need a house battery. my problem is whats the best way to get both of them to charge from the motor and not over charge or under charge one? and the only thing i will need to run on my house battery is the amp i am putting in the boat. it is a mb quart nau 660 amp to run my highs and subs. i know of the little red selector switches but i dont think they really play with charging correct.

 

[skargo]

Re: setting up a house battery and start battery

A switch with batt 1 batt 2 and both will do the trick. You might want to search as this has been discussed countless times here.

 

[Silvertip]

Re: setting up a house battery and start battery

If you intend to have the head unit on one battery and the amp on the other and have them isoltated from each other you may run into some "noise" issues. As for the "little red switches" I assume you mean a dual battery switch such as the Guest which has OFF, BAT 1, BOTH and BAT 2 settings. Your information about them not charging correctly is simply baseless and this is exactly what you need. Other options are a VSR (Voltage Sensing Relay) or ACR (Automatic Charge Relay). There are ample discussions and illustrations in this forum about the pro/con issues of each. If you plan to use the house battery as an emergency starting battery then your best option is a bual battery switch. Unless the VSR/ACR has a "combine" feature, you can't start the engine from the house battery. As for charging, two batteries can be charged from the engine without damage. The engine voltage regulator monitors "system" voltage and can't tell if you have one battery, two batteries or 10 batteries connected to it. The only issue is the amount of time it takes to charge "all" of them.

 

[bruceb58]

Re: setting up a house battery and start battery

Typically, the ACRs don't have enough current capacity to allow them to be combined to help start. You will fry them fast. Go with a switch and the ACR.

http://bluesea.com/category/2/productline/overview/329

 

[shaeleblanc]

Re: setting up a house battery and start battery

cool then the red switch i can run the amp to my battery in the boat and then wire another battery in. how long can i expect the battery to last with the engine not running with just amp and deck on playing.

 

[Silvertip]

Re: setting up a house battery and start battery

You didn't search the forum for the many discussions on DUAL BATTERY SWITCHES. Nothing is wired directly to the batteries except an automatic bilge pump. Battery 1 (the start battery) gets wired to BAT 1 on the switch. Battery 2 (the house battery) gets wired to BAT 2 on the switch. Ground terminals on both batteries get connected together and a cable runs from either battery to the engine block. The fuse panel and all accessories are then connected to the COM terminal on the switch. Whatever you have the switch set to will power everything and be charged by the engine. At anchor or at the dock you would typically have the switch set to BAT 2 (the house battery) which now powers everything thus saving the start battery. When you are ready to go switch to BAT 1 (or BOTH), start the engine and go. If you selected BOTH, both batteries get charged. If you selected BAT 1 only BAT 1 gets charged, if you left the switch on BAT 2 and the battery wasn't run down totally by the stereo and the engine starts, leave it set to BAT 2 so full charge current from the alternator can be dedicated to that battery. Google or use the forum search for DUAL BATTERY SWITCH. There is enough reading to make your eyes bleed.

 

[shaeleblanc]

Re: setting up a house battery and start battery

thanks for the reply i will get that switch then