www.iFourWinns.com
https://smwebhead.com/phpBB3/

Deep cycle batteries for starting
https://smwebhead.com/phpBB3/viewtopic.php?f=11&t=1693
Page 1 of 1

Author:  dgdake [ Sat Apr 05, 2008 4:05 pm ]
Post subject:  Deep cycle batteries for starting

I know Volvo and other manufacturers warn against using deep cycle batteries for starting, due to the heavy current load that starters put on a battery. On the other hand, I only start my boat in pretty warm weather so the battery should be near peak power and the engine isn't overly hard to start. Has anyone actually had or heard of a problem using a deep cycle battery for a starting battery?

Author:  Walt [ Sat Apr 05, 2008 8:24 pm ]
Post subject:  Re: Deep cycle batteries for starting

Deep cycle batteries have fewer and thicker plates. They are designed for a lower amp draw over a longer time frame. Starting batteries have more and thinner plates, allowing greater contact with the electolyte, thus quicker discharge/recharge and higher amp draw for shorter times. Therefore, using a deep cycle battery for starting would result in a higher power density (that is amps per sq in of plate area) and greater heating, cooking off the electrolyte, and reducing battery life. I spent 7 years maintaining batteries in critical back-up applications, and became well versed.

Read the info in the link below.

http://www.cabelas.com/cabelas/en/templ ... ieldguides

I only use Deep cycle for stereos, as fishermen use for trolling motors.

Author:  wkearney99 [ Sun Apr 06, 2008 8:23 am ]
Post subject:  Re: Deep cycle batteries for starting

So have two if you're concerned. I believe the new boats generally tend to have a dual-purpose sort of battery model. I can't recall which one at the moment. But if you've only got one battery you're not going to be able to restart the engine if you run it down. Like by leaving the radio running all afternoon, or a chartplotter (or all of the above). Many boats have batteries dedicated for starting only, one for each engine. Our 348 came with three; port and starboard engine and a 'system' battery for the accessories. I added a pair of 6V (in series for 12v) golf cart model batteries to the system circuit. No more low voltage issues even with all weekend use.

Author:  LouC [ Sun Apr 06, 2008 10:06 am ]
Post subject:  Re: Deep cycle batteries for starting

I have an old FW and the way the boat is wired I could not have a dedicated starting and cycling battery. I did use group 27 deep cycles for starting (had a pair of them and a switch) and running the bilge pump (moored boat, auto bilge switch), and they were fine for 5 seasons. Just replaced them with a pair of Deka group 27 dual purpose batteries, since they should meet my use needs better. With a boat on a mooring, you are always worried about water getting in either from storms or a leak. You need adequate power for a bilge pump at all times, and a starting only battery may not cut it.
Keep in mind my old boat is a carb and points+condenser engine, the cranking voltage needs are not what modern engines have so I'd follow what the engine manufacturer says.

Author:  230 Mike [ Sun Apr 06, 2008 5:20 pm ]
Post subject:  Re: Deep cycle batteries for starting

A pair of Interstate dual purpose group 27's here, and when the time comes to replace them I plan to use the same. Been very happy with them so far.

Author:  BrentC5Z [ Mon Apr 07, 2008 4:33 pm ]
Post subject:  Re: Deep cycle batteries for starting

Only use dual purpose or cranking for this.

Author:  dgdake [ Wed Apr 09, 2008 10:38 am ]
Post subject:  Re: Deep cycle batteries for starting

Thanks for the information and feedback. I'll stick to dual purpose and won't worry too much.

Author:  van [ Wed Apr 16, 2008 4:08 am ]
Post subject:  Re: Deep cycle batteries for starting

Depends on the boat, but I would use a dedicated starting battery for starting. I have owned several boats and some did not fare well even with a dual purpose battery (slow cranking speed) while I had an old Chris Craft with that had been "converted" from 6 volts to run on 12 (actually means the starters were left unchanged but deemed to be strong enough for this) and it had the same group 27 deep cycle battery for 5 years until I sold the boat. The point is while the Chris did fine with the deep cycle battery (single battery for 2 engines to boot), I had trouble with dual purpose batteries in other boats. I now only use dedicated starting batteries for starting.

Author:  Jim_R [ Wed Apr 16, 2008 4:41 am ]
Post subject:  Re: Deep cycle batteries for starting

My '07 H200 came with a Dealer installed dual purpose Group 27 battery - 120 Minutes Deep Cycle, 185 Minute Reserve, 720 CCA. For my engine, Volvo calls for a dedicated starting battery with minimum 650 CCA and 135 minute reserve capacity. So far I've had zero problems, and did have some extended stereo use on the hook with the standard stereo (no amp). I'm sticking with the dual purpose this next season, although I am adding a second group 32 deep cycle battery for House systems and new Stereo Amp. I'll be using the Blue Sea Systems "Add a Battery" switch and ACR to isolate starting and house systems so there should be even less load on the starting battery, although more of a load on the 75A alternator keeping both batteries topped off.

Author:  BrentC5Z [ Thu Apr 17, 2008 12:09 pm ]
Post subject:  Re: Deep cycle batteries for starting

Jim_R wrote:
I'll be using the Blue Sea Systems "Add a Battery" switch and ACR to isolate starting and house systems so there should be even less load on the starting battery, although more of a load on the 75A alternator keeping both batteries topped off.

It's my understanding, isolators are available that will only send alternator output to the second battery when the first has a full chage. Thus, no extra load.

Page 1 of 1 All times are UTC - 6 hours [ DST ]
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/