Deep cycle or starting battery same specs?

[Salmonseeker]

Okay guys I was looking at batteries the other day and noticed something.<br /><br />There was a deep cycle battery with 650MCA and 130RC. There was also a starting battery with 625MCA and 80RC. They were both the same price.<br /><br />So if the deep cycle has more MCA(marine cranking amps) and more RC(reserve capacity). Why would someone want to buy the starting battery?

 

[Paul Moir]

Re: Deep cycle or starting battery same specs?

If those RC numbers are true & trustworthy, the deep cycle battery should be physically larger. It is foolish to purchase a smaller battery, all other factors being equal. Factors like cost, brand, importance of weight and size on boat, that sort of thing.<br /><br />If this is for your 50hp, forget about the cranking amps specification. The starter just doesn't draw that much. A deep cycle is far more useful and will power the starter just fine. So Reserve Capacity is the critical number. 130 RC = 54 Amp Hours if they're being honest.

 

[Salmonseeker]

Re: Deep cycle or starting battery same specs?

Hey Paul<br /><br />You may be right about the size. I did not take that into account. It is for my 50HP which only requires 360 CCA or 465 MCA according to the owners manual.<br /><br />I am trying to decide wether or not to install a second seperate battery for my bow mount trolling motor. The boat came factory wired for it. I might just go that route instead of running new wires to the back of the boat. That was what I originally going to do.<br /><br />I currently have a very large deep cycle for my starting and accesory battery. I never went below 3/4 charge all last year. I was thinking of moving that one up to the front for the troller and purchasing the deep cycle above for my starting and accesory battery.<br /><br />I just need to replace the fuse that was wired from the factory. It came with an auto reset 40 AMP fuse. My motor reccomends a 50AMP.<br /><br />Thanks Jay

 

[Paul Moir]

Re: Deep cycle or starting battery same specs?

If you don't mind the extra expense, weight and complication, two batteries are a really good idea. If your starting battery dies, you have a backup.

 

[Salmonseeker]

Re: Deep cycle or starting battery same specs?

I think I will go the two battery route. Just to be safe and not have to worry about running the trolling motor to long.

 

[18rabbit]

Re: Deep cycle or starting battery same specs?

Originally posted by fisherman38:<br /> I currently have a very large deep cycle for my starting and accesory battery. I never went below 3/4 charge all last year.

Jay – something happens when you only use the top charge of a battery; the battery lasts a real lot longer. A batt is a chemical reaction that is in a constant state of decay. The less change in the internal voltage, the slower the decay. The less energy you take out of a batt, the less change the internal voltage sees. Never discharging below 75% is a good thing.<br />

 

[Salmonseeker]

Re: Deep cycle or starting battery same specs?

Thats good to hear. Thanks

 

[cuzner]

Re: Deep cycle or starting battery same specs?

Rabbit is right,deep cycle batteries are made to drained more than starting batteries. deep cycle are heavier than starting batteries because they have thicker plates . I don't know what size your boat is, but be careful in placement of the the batteries, that much weight can seriously affect handling if not placed right.<br /><br /><br /> Jim

 

[Salmonseeker]

Re: Deep cycle or starting battery same specs?

I think I will be okay with the extra weight. The boat is designed to use two batteries and has a weight capacity of 1200lbs. It is already factory wired and has a spot to accomodate an extra battery.<br /><br />Jay

 

[demsvmejm]

Re: Deep cycle or starting battery same specs?

18R, that's counter to any advice for rechargeable batteries I have ever received. I even worked for a company that provided factory level training and told us that we needed to periodically draw down even automotive batteries to destroy any memory that they may have.<br /><br />And I was advised by my parts supplier that a deep cycle battery and a marine starting battery were no different except for maybe the CA ratings. I asked about it because I was installing a battery on my camper and was considering transferring the DC from my boat and putting the new battery in my boat.

 

[Paul Moir]

Re: Deep cycle or starting battery same specs?

Draining down any rechargable battery all the way is a recipe for destroying them. Cells may be a different story with some types but not with Lead Acid. <br />The "memory effect" only exists with older NiCd batteries and was only a serious problem in satillites and other devices with precise periodic charge/discharge levels. That is not in 99% of applications. Just read the battery manufacturer's literature.

 

[bandsaw48]

Re: Deep cycle or starting battery same specs?

Exactly Paul... the deep cycle battery with it's thicker plates can be depleted and recharged many times before they are dead for good. The starting battery may only survive a fraction of that. <br /><br />Deep cyclce up front for trolling and economical starting in back for cranking in my humble opinion.<br /><br />Greg

 

[MajBach]

Re: Deep cycle or starting battery same specs?

Most here are right on the money: deep cycles are meant for continuous low current use with starters are the other way around. I have found from experience that deep cycles can be used in a car and last just as long as an auto battery when treated like one, although the experts would call me a liar. On the other hand, I once killed [permanently] an auto battery in 20 minutes when I hooked it up to a trolling motor - I kid you not.<br />I'd say, buy the deep cycle and use it for starting.

 

[jch7450]

Re: Deep cycle or starting battery same specs?

i'd rather have a little extra weight, on board, then to loose a few pounds rowing back home lol

 

[ZmOz]

Re: Deep cycle or starting battery same specs?

Originally posted by David L. Moore:<br />I even worked for a company that provided factory level training and told us that we needed to periodically draw down even automotive batteries to destroy any memory that they may have.

The worst thing you could possibly do to ANY kind of lead acid battery - deep cycle, starting, sealed, flooded, AGM, gel...whatever, is to run them dead. Even just one or two complete discharges to a starting battery will have an effect on it's life and remaining capacity. The only type of batteries that have a memory effect are nickel based - nicd and nimh, and even with them, this problem is usually blown way out of proportion. All other types of batteries do not have any sort of memory effect what so ever.