Re: Deep Cycle vs. Starting
Trolling motor batteries are deep cycle. They are especially made to cycle to discharge, be run down and fully recharged, repeatedly. They have a few thick plates for ruggedness and few in that you usually don't need much current to run the troll; like you need in cranking and engine.<br /><br />Then there are the combination deep/reg which I assume is the medium of of plate thickness and number.<br /><br />Then the regular battery which has lots of thin plates for the 200 amperes or so you need to start an engine. They are thin cause the battery can only be so big dimensionally, but needs so much surfact area to get the current.<br /><br />My experience with batteries is that the thin plates do not do well with deep cycling, recharging, and vibration. Don't remember the particulars, but they (the plates) scale up (think they call it "sulfide up") and break off. The pieces of plate and/or scale settle to the bottom and over time build up to the point that they short the plates. Soon as they start doing that the capacity of the battery reduces till it is finally unusable. <br /><br />So for marine, industrial, and OTR truck applications they have large batteries which allow for thicker plates and still keep the surface area up (hi number) for high current starting. <br /><br />Deep and regular batteries have (seem to have) a different specific gravity for full charge which translates to voltage at a particular temperature. The voltage on the troller is lower than the reg so in parallel, as mentioned by Dunaruna, you will fry the troll trying to get the reg up to full cap. I know this because I had a battery charger that had a switch on it for reg or deep types. It reduced the "full charge sensor" voltage requirement for the trolls.<br /><br />I bought a 40 hp diesel farm tractor a couple of years back which had a trolling motor battery for the cranker, believe it or not. Aren't advertised to do it, but this sucker could pump out the 200 amps required to get the diesel to start. But I wouldn't recommend it. Replacement with a regular HD farm battery did get her to spin faster and obviously start sooner. On your big 350 cu in I would think this is definitely a no-no.<br /><br />Go to a battery web site and they should tell you all about it. Exide is one.<br /><br />So, what to get? If you are starting, get a heavy duty marine, industrial, or OTR battery. You can run a lot of accessories for a long time (with the engine off) on these babies, before you do much discharging. If you are running a troller, get a troller.<br /><br />I like OTR batteries cause you can get a size 31 maint-free for about $56. (Duralast brand as I recall...think the plant is owned by International Harvester.<br /><br />Truck dealers buy them by the skid. They have 3/8" threaded stud terminals (whereas it's sister the popular 27 has push on-lead studs). Makes hookup to all your electrical goodies really easy and clean and there is no corrosion like with lead.The last ones I bought had 950 CCA believe it or not. <br /><br />I have a 300 cu inch diesel farm tractor and just one of these babies will start her right up summer or winter.<br /><br />HTH<br /><br />Mark
