 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
| HomeDiscussion GroupsBoatsPaddle BoatsSailingCruisingBuildingElectronics Related Topics CarsMotorcyclesMore Topics ... |
Boat Forum / Building / January 2006isolators
I'm starting to give some thought to my power source on the house boat I am refitting. I am leaning towards using isolators to seperate the battery banks. I would like some experienced feedback on what type of isolator to use; diode, FET or solid state? All I know at this point is that the drop across the diode type can play havoc with the battery life because of the voltage drop never allowing a full charge (?). The other two kinds I have not been able to get anything except that they have a much smaller v drop (FET) or none (solid state). And that is from sales materials. Will using isolators allow me to forgo the 12Both switch and just use an in line on/off switch? May seem like a dumb question but how do I know what size of charger I will need or does size (amps) matter other than how quick it will charge the batteries. I plan on having two start and two house batteries. How important/neccessary is it to have a galvanic isolator on the AC side? THX I'm looking forward to others' comments, but first: The only diodes available today are "solid state" devices. Forward voltage drop will typically be 0.5 to 0.7 volts unless it's a Schottky type. Could be compensated for by sensing on the battery side or by telling the controller there's an isolator. FETs (Field Effect Transistors) are "solid state" devices. The voltage drop is a function of current, figure 10 to 200 ohms on-resistance. Huh? Roger derbyrm@NOSPAMinsightbbNOSPAM.com http://home.insightbb.com/~derbyrm > I'm starting to give some thought to my power source on the house boat I > am [quoted text clipped - 17 lines] > > THX The most modern alternative is the "Battery Combiner". The connections in this device are actual relays (0.0 V voltage drop). They leave the batteries isolated until they see 14 (approx - value adjustable) on one of the banks, indicating it is being supplied by a charger. In this case, the relay closes, combining the batteries for joint charging from the single source. When the charging voltage disappears, the relay opens again, isolating the batteries. bob > I'm looking forward to others' comments, but first: > [quoted text clipped - 33 lines] >> >>THX Isolators cause votage drop and are not optimum for deep discharge battery banks... Not recommended by me.. Ideally you will have two engine start batteries with an A-B-OFF switch... Use the standard engine alternator and fixed voltage regulator on the engine to maintain the start batteries... Autos use the fixed voltage regulator and you get years of life and many thousands of starts from your car battery... It will do the same on your boat... Alternatively, for two engine start batteries an isolator will work and probably never cause you any problems and I would not criticize that type of installation... However for house battery banks, you want and A-B-OFF switch for the two house banks <never BOTH>... You want a separate, heavy duty alternator for charging these... You need a three charge regulator to control the charge rate based on the battery state and the battery temperature...... You need the heavy duty alternator for ramming a charge to the big house batteries, a task that the standard automotive style alternator was not designed to handle... Running a big alternator into the start battery is a waste as it cannot accept more than 60 amps, even when discharged from a hard start... WIth volt meters on each house bank you can switch between A and B as you discharge the batteries, never going below 50% charge state on either... Once A is 50% and B is getting there it is time to fire up the engine and ram a charge into B, and once it is up switch to A.. Yes, it requires you to monitor the banks and make the decision when to charge/switch, but it is the only way to avoid the switch being on BOTH and having both banks exhausted... Hers are a few web sites to give you food for thought... http://www.powersolutions.com.au/index.html http://www.charlesindustries.com/main/ma_alternre.htm http://www.zena.net/htdocs/alternators/mar_alt.shtml#Top http://www.e-marine-inc.com/products/alternators/marinealtsgas.html There are lots more vendors of similar products, but I leave it to you to do the searching... cheers ... denny MV Levitation Thanks for the input... and the links Denny. I will have a look. > Isolators cause votage drop and are not optimum for deep discharge > battery banks... Not recommended by me.. [quoted text clipped - 37 lines] > cheers ... denny > MV Levitation There is extensive FAQ information on combiners at at http://www.yandina.com/combInfo.htm |
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2009 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.