Increasing available amps

[Broke sailor SV Marcell]

My boat has a single 12 volt battery, approximately 80 amps. I would like to increase rhe capacity by installing a similar sized battery in parallel. I am not changing the loading on the boat. Can I do this simple mod without having to change the alternator size? I also want to hook up a Link 10 to monitor battery status.

 

[Nice N Easy]

Battery

Simply put yes. Not so simply put, maybe. If you want a house and a start battery, then you need to run through a selector switch. Might want to anyway. Most run them through a switch, so as to be able to protect one bank from being run down to the point of not starting the engine. If you just want them together, works fine. But the existing battery must be in real good condition, or it will not allow the new battery to fully charge. There are lots of diagram on how to do this. Probably the monitor you want to install will have the diagrams.

 

[Trevor - The Offshore Store]

Adding battery capacity

Nice and Easy answered this question well. Upgrading the alternator will certainly charge the batteries (assuming you will have two) faster, but the one you have will get the job done in due time - once you have a monitor installed you'll know how long. I'd go ahead and add the battery, but as Nice and Easy mentioned, you should consider whether you want a separate start and house bank (i.e. one for each dedicated purpose). For simplicity, you can just tie them together in parallel if the one you have is relatively new like you suggest, especially if you plan to install and keep an eye on that meter.Have fun!Trevor

 

[JC on Bainbridge]

Mixing good with bad, or new with old.

Like Nice n Easy have stated, if you want them together, make sure the old one is good. If not, and you put a new one along with it, the bad will pull the good one down to the bad, not the other way around. Whenever you tie multiple batteries together, make sure you replace all of them at the same time, with same type of batteries, such as flooded, AGM, or gel.