Re: synthetic oil conversion, and battery connection
AAAAAAhhhhhooooooyyyyy BASSNSNOW..<br />Here's my view (for what it's worth) on this popular subject:<br />-Outboard charging systems are not robust<br />-When they break............big money<br />-Most charging systems are not designed to deliver their max. output for long periods<br />-I can't remember the exact numbers, but around 60% of max. output is safely maintainable. eg. a 30 amp system can supply 18 amps over long durations.<br />-Most manufacturers and rebuilders will not warranty a charging component if the component is installed in a system with a low battery. Why??!! Because the load that the low battery and accessories present to the charging system may damage the system from extended periods of a high charging rate(heat).<br />Now to the question at hand....<br />-if you connect b1 and b2 together in parallel, some neat things are going to happen. You will increase the on time for your trolling motor. When you go as far as you can go......the batteries may be too low to start the engine(no big deal, that's what paddles are for..LOL) So you wait awhile, and as we all know, the batteries will recover somewhat in a few minutes and probably get you started (you wipe off your brow and say wheeeeew, I was lucky!) Question! How much current does b1 and b2 draw when they are being charged at 14volts? ans.=about 25-45amps each (depending on size, age, temperature and electrolyte mix ratio). That means that your charging system will put out its max for a long time before these batteries are up in charge and start drawing less. So you head back to shore > charging system overworking > batteries not fully charged in that short of time (but a full stringer of bass!) You try starting it when you get to shore, and it starts. YES!!! I guess there's nothing wrong!! Then you trailer the boat for another week or two...While your batteries are sitting there in the 'less than fully charged condition' they are slowly becoming permanently sulphated(eventually unusable) couple of weeks go by, and you head out again. The engine starts...wheeeeew!!! Nothing wrong!!! Off you go. Batteries still low from last time > charging system working its bag off. You get to your fishing spot(batteries still not up in charge)....switch on the trolling motor and find that you're not getting the distance you got before using the troller. Barely get it started > head back home > charging system again overworked > batteries still not up....you get to shore > try restarting > engine starts > wheeeew!!! Nothing wrong.......wipe off your brow and off you go!!!!<br /><br />Are you seeing a pattern here or is it just me!! Eventually you will have a pair of permanently sulphated batteries (unusable) and maybe even a damaged charging system...You look at the batteries and say 'I'll never buy *almart batteries again, they're sh*t!!.....LOL<br /><br />If this was an inboard, the solution is simple---put in a high output alternator (one that can handle the 50-90amp requirements of two low batteries,add in a safety factor to the alternator's spec) and add in a continuous duty solenoid to connect b1 and b2 together at the appropriate times.(NOT ALL THE TIME)<br /> But you don't have that option. Not easy to find a big output charging system for an outboard.<br /> If it was me:<br />1. B1 = Maintenance free battery. Why? maintenance free batteries have less gassing, less spillage, higher internal resistance when fully charged > less current draw under normal operation. Oh yeah, why doesn't everbody use m. free? They can't take deep cycling for long.(but we're not going to deep cycle them, and they'll live for 7-10 years) connect b1 soley to the OB<br /><br />2. B2 = Large deep cycle battery or regular maintenance battery (almost as good) If you have a large demand for power, buy a larger battery, not two small ones. Even an '8D'series heavy equipment battery battery will work nicely.<br />3. Do not expect the OB to charge this battery. Couple these batteries together with a continious duty solenoid controlled by a small push button for emerg. starting in the event that B1 fails.<br />4. Put a current limiting device(resistor or high forward resistance diode) from B1+ to B2+ This will allow the OB to slowly and safely charge B2. With this current limiter in place, B2 will take a very long time to come up in charge, therefore I'd recommend complimenting the system with a small solar panel which will slowly chip away at the sulphation and get the batteries up in charge even while the unit is aground.<br /><br />With this system, B2 will not pull down B1, thus you won't be stranded. B2 will not over-burden the charging system because of current limiting. The solar panel will slowly bring both batteries up to charge.<br /><br />I can hear some guys out there saying.....aaaaaahhhhhhhh that's a load of sh*t, I just connect them together and away I go..... Yeah, It'll work (for awhile)These are the guys on this website with charging system and battery failure problems......<br /><br />Hope this helps!!<br />