barrystrs Posted August 1, 2011 Report Share Posted August 1, 2011 When I go on holidays I don't have access to hydro. Could I connect booster cables from starting bat to charge trolling batt? As long as I don't leave it connected while trolling to run down starting batt. I usually do more sight seeing on holidays and don't run down the trolling battery, but it would be nice to keep it topped up. I don't plan on using a batt isolater, but I'm surprised that I have never heard of someone doing this. Perhaps there is a safety issue I have not thought of. Thanks for any comments or suggestions. Link to comment Share on other sites More sharing options...
Fisherman Posted August 1, 2011 Report Share Posted August 1, 2011 When I go on holidays I don't have access to hydro. Could I connect booster cables from starting bat to charge trolling batt? As long as I don't leave it connected while trolling to run down starting batt. I usually do more sight seeing on holidays and don't run down the trolling battery, but it would be nice to keep it topped up. I don't plan on using a batt isolater, but I'm surprised that I have never heard of someone doing this. Perhaps there is a safety issue I have not thought of. Thanks for any comments or suggestions. There are a couple of unknowns here, how big is your gas motor, how far do you run at any speed above idle to charge the trolling battery. Safety issue, none that I can think of other than don't trip over the booster cables and make big lightning bolts,,,a.k.a. sparks. Depending on the output of the alternator on the motor and time spent running at speed, you can achieve some recharging. Link to comment Share on other sites More sharing options...
ccmtcanada Posted August 1, 2011 Report Share Posted August 1, 2011 I'm not an expert here, but a quick google search came up with this... "Yes, it is possible, but to a very limited extent. The reason for this is that in order for a rechargable battery to charge there must be electrical current flowing through it. The greater the difference between the volatages of the two batteries, the greater the flow rate. With one fully charged battery and one dead battery, if connected with the polarity correct, then there will be some current flow, and thus a little bit of charge on the dead battery. Again, the charge gained by the dead battery will be very small. Generally, normal vehicle alternator output voltage is from 12 1/2 volts [minimum] to 15 or 16 volts, which results in a relatively rapid charging rate." What about attaching an inverter to your starting battery and using the deep cycle charger you have, plug it into the inverter and charging that way? I'm not sure if that will drain your starting battery quickly...don't have specs of usage on inverters handy... Link to comment Share on other sites More sharing options...
mercman Posted August 1, 2011 Report Share Posted August 1, 2011 Assuming you have a car or truck with you, why not charge it with your vehicle? There are inverters and lighter adaptors available at CT for doing just that. Link to comment Share on other sites More sharing options...
ccmtcanada Posted August 1, 2011 Report Share Posted August 1, 2011 If you have a car or truck, I'd do what mercman suggested. Link to comment Share on other sites More sharing options...
vance Posted August 1, 2011 Report Share Posted August 1, 2011 Assuming you have a car or truck with you, why not charge it with your vehicle? There are inverters and lighter adaptors available at CT for doing just that. We looked into that and a couple of other charging methods for trolling motor batteries before I retired from GM in Oshawa.We went to the Delco engineering rep and asked him,he didn't know so he asked them in Detroit.The HEAD engineer for charging systems said,and I quote Modern 12v alternators with all the load that they have on them are not designed to charge a depleted battery ONLY to MAINTAIN one and repeat heavy draws required to charge a battery will quickly burn out an alternator even if only done a few times.And BEFORE we get into a GM bash Delco designs and build parts for ALL car manufacturers and this guy was in charge of his department. vance Link to comment Share on other sites More sharing options...
Fisherman Posted August 1, 2011 Report Share Posted August 1, 2011 What about attaching an inverter to your starting battery and using the deep cycle charger you have, plug it into the inverter and charging that way? I'm not sure if that will drain your starting battery quickly...don't have specs of usage on inverters handy... You're going from DC to AC back to DC, you're wasting a bunch of power in the conversion and in the process, you're draining the starting battery. Not a good idea. Link to comment Share on other sites More sharing options...
DRIFTER_016 Posted August 1, 2011 Report Share Posted August 1, 2011 Just do what I do and take a 1000 watt generator. I just plug my on board charger in and have at 'er. No on board charger, just bring yours with you. As an added bonus you can run other stuff off the genny too. Like lighting or a bug zapper. Link to comment Share on other sites More sharing options...
Canadiancontent Posted August 1, 2011 Report Share Posted August 1, 2011 Just do what I do and take a 1000 watt generator. I just plug my on board charger in and have at 'er. No on board charger, just bring yours with you. As an added bonus you can run other stuff off the genny too. Like lighting or a bug zapper. Minn Kota makes an DC alternator charger: http://store.minnkotamotors.com/category/392877/on-board_dc_alternator_char Link to comment Share on other sites More sharing options...
Woodsman Posted August 2, 2011 Report Share Posted August 2, 2011 As long as you don't drain your deep cycle battery too low why not just hook it up to your motor directly (from time to time) instead of your starting battery to charge it when you are boating from place to place. Link to comment Share on other sites More sharing options...
spinnerbaitking Posted August 2, 2011 Report Share Posted August 2, 2011 A buddy bought a Solar panel he takes up to Gogama when they go up & he said he was surprised how much it helped just leave it on the deck all the time SBK Link to comment Share on other sites More sharing options...
gottobecdn Posted August 2, 2011 Report Share Posted August 2, 2011 looked into doing this aswell...talked with an interstate guy i know and he said it would work but deep cycle batts like to be 80-90% drained and then charged slowly, charging to quickly and to often would decrease the batt life. other option would be an onboard inverter/ charger but $$$$.....on the other hand batts are not cheap.. Link to comment Share on other sites More sharing options...
Fisherman Posted August 2, 2011 Report Share Posted August 2, 2011 looked into doing this aswell...talked with an interstate guy i know and he said it would work but deep cycle batts like to be 80-90% drained and then charged slowly, charging to quickly and to often would decrease the batt life. other option would be an onboard inverter/ charger but $$$$.....on the other hand batts are not cheap.. I think you should go down to the interstate guy you know and have him read a few chapters of Batteries 101. DC batteries don't like being discharged below 50% and going beyond that really reduces their usable lifespan. Charge rate is normally C20 or 20% of their capacity. If he says 80-90% he's doing nothing more than trying to sell batteries. Link to comment Share on other sites More sharing options...
BillM Posted August 2, 2011 Report Share Posted August 2, 2011 A buddy of mine lets me borrow his little Honda generator. That's what I'll charge the trolling motor battery with. Link to comment Share on other sites More sharing options...
barrystrs Posted August 2, 2011 Author Report Share Posted August 2, 2011 Thanks for the great ideas and comments. I use a solar charger for the ice hut but I don't think it is suitable for this application because in order to get enough output you need a big/expensive one and it could easily get damaged. If I use my original plan I am a little worried about overloading the alternator, but if I use the isolator/charger, that someone else provided a link to, it limits output to 10 amps which will protect the alternator. Sounds good! I hadn't thought of a portable generator, but I think this might be the best solution as it can also be used for other things. Thanks Link to comment Share on other sites More sharing options...
Raf Posted August 2, 2011 Report Share Posted August 2, 2011 (edited) get a 2nd battery. little cheaper than a genny. Edited August 2, 2011 by Raf Link to comment Share on other sites More sharing options...
DRIFTER_016 Posted August 2, 2011 Report Share Posted August 2, 2011 get a 2nd battery. little cheaper than a genny. True, but if you are going to be off grid for more than a couple of days you will just have 2 dead batteries. Link to comment Share on other sites More sharing options...
gottobecdn Posted September 20, 2012 Report Share Posted September 20, 2012 I think you should go down to the interstate guy you know and have him read a few chapters of Batteries 101. DC batteries don't like being discharged below 50% and going beyond that really reduces their usable lifespan. Charge rate is normally C20 or 20% of their capacity. If he says 80-90% he's doing nothing more than trying to sell batteries. Guess I should have know better than to trust a sales man...... Quoted from Wikipedia " A deep-cycle battery is a lead-acid battery designed to be regularly deeply discharged using most of its capacity. In contrast, starter batteries (e.g. most automotive batteries) are designed to deliver short, high-current bursts for cranking the engine, thus frequently discharged of only a very small part of their capacity. While a deep-cycle battery can be used as a starting battery, the lower "cranking amps" imply that an oversized battery may be required. A deep-cycle battery is designed to discharge between 50% and 80% depending on the manufacturer and construction of the battery. Although these batteries can be cycled down to 20% charge, the best lifespan vs cost method is to keep the average cycle at about 50% discharge,[1] as there is a direct correlation between depth of discharge on the battery and the number of charge and discharge cycles it can perform.[2] " Sad part is our company does quite bait of business with this guy. Was well worth the couple hrs of my time reading up on batteries for myself. Link to comment Share on other sites More sharing options...
Muskieman Posted September 20, 2012 Report Share Posted September 20, 2012 Hook it up to the vehicle , works like a charm, many tourney anglers I know do it at the motels the night before , I do it myself ..don't worry the alternator can handle it . Link to comment Share on other sites More sharing options...
Gerry Posted September 20, 2012 Report Share Posted September 20, 2012 I've got one of these on board my boat and it seems to work fine. My link It's a bit pricey but it does what it claims to do....delivers 14 volts at anything over 1000 RPMs'. I have the same issue in that I don't have power available and I stay for 3 - 4 weeks at a time without accesss to electicity. Haven't had any issues with dead trolling batteries and I'm on them all the time. The thing though is that you're not going to get a lot of charge if you make short runs with the big motor. Link to comment Share on other sites More sharing options...
R. J. Kovacs Posted December 2, 2012 Report Share Posted December 2, 2012 The engineer speaks the truth. While possible to recharge a boat battery from the electrical system of the towing vehcle it will take quite a long period of time. If driving for several hours, then maybe. Seems foolish to attempt to do this with a staionary vehicle idling for hours. Link to comment Share on other sites More sharing options...
R. J. Kovacs Posted December 2, 2012 Report Share Posted December 2, 2012 You would be draining one battery in order to recharge another. You will loose a lot of energy in the process, DC to AC then back to DC. The voltage of the donor battery may drop below the cut off point of the inerter long before any significant charging can be accomplished. Link to comment Share on other sites More sharing options...
R. J. Kovacs Posted December 2, 2012 Report Share Posted December 2, 2012 Good idea, but the charging circuits on the smaller outboard engines will not be designed to run at full load for any great length of time. They are designed to replenish a relatively small starting battery quickly, and then just maintain it. Attempting to charge a larger, deeply discharged trolling motor battery would require in my opinion, several hours of engine run time and would likely very quickly damage the generator on the engine due to it running at full load longer than it was designed to. It may work for a while. You would have to consult with the engine manufacturer and see what the maximum rated output and duty cycle of the charging ciruit would be. You may be able to do this with the larger engines, but the smaller ones I doublt would be suitable. A good rule of thumb to start with would be how many hours of trolling motor use each day versus hours of engine run time? Link to comment Share on other sites More sharing options...
BillM Posted December 2, 2012 Report Share Posted December 2, 2012 (edited) You've got an alternator in your big engine, why not use it to charge all your batteries? If I just didn't buy an 2 bank onboard charger for the Lund, I would have done a setup similar to a buddy of mine just did. Also if you have a 7 pin trailer harness, you'll charge everything while driving as well. Seems like the best solution out there. Maybe Dave will come in here and explain it a bit better then I did, lol. Edited December 2, 2012 by BillM Link to comment Share on other sites More sharing options...
fishindevil Posted December 3, 2012 Report Share Posted December 3, 2012 Why not run them parallel ?? I have a battery selector switch in effect it just makes 1 big 12 v battery I can direct the charge from my engine to either battery or both or just my trolling motor battery it works and when I'm running down the lake it sends a pretty good charge !!!! Not sure how it works as a freind hooked it up that way but it does I'm not sure if I'm explaining it correctly ?? Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now