Marine battery deep cycle or not

[dean12m]

my battery has dropped a cell so need to replace . its a deep cycle battery.

is this the best way to go as the starting battery??????

i'm running nav lights B pump and gps/sounder off the one battery.

is this the best set up or are DCB's not ideal as a starting battery? in my 4x4 i'm running one of each one to start and one for accessories (DCB) , is it different in the marine world
dean

[shy guys]

Deep cycle batteries won't last long for starting motors I run both dcb for night time run everything off whilst fishing then switch to good cranking battery to start the boat

[lucee81]

I run 1 start and 1 dcb however if you switch them and something happens to your start battery you can always flick the switch and get home.
People will also argue that leaving them separate and changing the battery lugs if in trouble is a better idea. Less parts to rat and go wrong keeping it simple on smaller boats is normally the best way.

[NAGG]

No ..... A marine battery is what you need . A deep cycle doesn't have the cranking ability .
Marine batteries are build with both cranking (CCA) and deep cycle capabilities .
The ideal set up is a Marine battery & house (deep cycle) via an isolator ....... you run around / start your boat on the marine cranking battery & use the deep cycle house battery when sitting for long periods on the anchor or drift (without the motor running)

Chris

[dean12m]

thanks for the info what was in it was a century marine pro 400

Dean

[NAGG]

Here is a bit of a guide for the Century marine pro range ...... looks like I need to add a second battery quick smart

chris

[juggernaut]

I recently bought a deep cycle lead acid battery and after a bit of research found this Trojan battery had decent capacity for a Group 27 battery....115AH, 200 mins RC, 620 CCA.....if your budget can stretch that far.

http://www.everybattery.com.au/prodd...php?prod=27TMH

Bit of a guide and brands of batteries

http://www.everybattery.com.au/deep_...marine-pro.php
http://www.everybattery.com.au/deep_...ies_marine.php

[LittleSkipper]

What I would like to know is if you have a switch that can be changed from Batt 1, Batt 2, Both 1 & 2 and off course OFF.

Can you run on Both 1 & 2 if you had 1 normal start & 1 Deep Cycle or would you have to keep switching between Batt 1-start & Batt 2-Deep Cycle?

Currently I run 2 normal calcium battery's (550CCA) that can run individually or both. Most of the time the switch is always on both.

Is this an okay thing to be doing? or perhaps not so okay in case I end up with two dead batteries? I know the alternator is putting back some of the charge but I understand the inevitable can always happen?

[juggernaut]

Provided the batteries are the same chemistry then paralleling the batteries is OK. However, as you've pointed out you still run the risk of having one dead battery pulling down the other and not being able to start.

You'd be better running dedicated isolated batteries for starting (cranking battery) and electrics (deep cycle battery). Preferrably use a switch arrangement that does not parallel the batteries and that can isolate the dead battery. You'd also want a deep cycle battery that can double as a start battery if and when needed. Not all deep cycle batteries can be used as starting batteries.

[WalrusLike]

Many folk (including me) use the 'out on one... Back on the other' system.

Advantages:
- both get used regularly so you are familiar with their health and prove the wirings ok

- one can't bring down the other

- any issues like shorting or unusual drain that arise on a trip you always have one unaffected battery available to get you home.

- can have dissimilar battery types and capacities.

Cons:
- have to manually manage it

- need both batteries to have a 'motor starting' ability

The only reason to run on both is if you need double grunt for some reason to start... Maybe both flattish but together enough to get going?

Be aware that you risk blowing the rectifier if you swap while motor is running.

[LittleSkipper]

Thanks for the advice gentlemen! The debate on batteries I think will forever be a never ending one? We all know motor vehicle/marine batteries have a very short life span. Only last year I got caught out unexpectedly when my car battery (2.5 years old) died whilst out & about one morning. Think I'll stay away from Deep Cycle and continue to use standard starting batteries and battery charge them as and when required.