| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 53.1 | I won't charge 2 at a time again | HPSCAD::WHITMAN | Acid rain burns my BASS | Mon Jun 20 1988 09:34 | 8 |
|
I tried charging 2 12 volt batteries hooked in parallel with a
relatively cheap automatic charger and 'smoked' it (as in melt down). I don't
know what would happen using the charger/alternator off your engine. Until I
hear of someone with positive experience in this area, or have someone tell me
where I screwed up, I now charge my trolling motor batteries one at a time...
Al
|
| 53.2 | Do it on the traier (I do) | MENTOR::REG | I fixed the boat; So, who want to ski ? | Mon Jun 20 1988 11:33 | 23 |
|
I know this won't work for everyone, but if you trailer your
boat it can help to wire a battery charging line into the trailer
wiring. All the way to the ramp and all the way home you have whatever
the car's alternator puts out available to your boat battery(s),
well, most of it.
Reg
Diode isolator schematic:
+'ve source
--------+---------------+
| |
V diodes V
- -
| |
| batt +'ves |
--- ---
- -
| batt -'ves |
---------+---------------+
-'ve source
|
| 53.3 | 2 at a Time Should Work | WORSEL::DOTY | ESG Systems Product Marketing | Mon Jun 20 1988 11:39 | 9 |
| Sounds like the key to battery charger meltdown would be "inexpensive"
-- a good charger should have current or thermal limiters to avoid
this problem.
I've been running a dual battery/diode isolator on a truck for close
to 20 years with no problems. Shouldn't be a problem with the
alternator on the boat motor (they are current limited -- on cars,
the electrical system will draw from both battery and alternator
at low RPM).
|
| 53.4 | Guest isolator........ | MRMFG1::J_BORZUMATO | | Mon Jun 20 1988 13:28 | 15 |
| bill, the Guest Co. makes a device call a battery isolator, that
sells for about $20 or so, that does just what you want.
the box is well sealed and can survive in some nasty enviornments.
I have one, this guy is for 3 battery banks, (3 batteries)
the one your looking for is for 2 batteries and one alternator.
the're easy to install. the idea of these guys is that each battery
doesn't know that other exist, the diodes act as a one way valve,
and current can only flow in one direction. if one battery is
taking a dive, it can't survive on the other.
hope this helps.
jim.
|
| 53.5 | Works Great | CRAKRS::KELTZ | Onward thru the fog | Mon Jun 20 1988 14:14 | 7 |
| Jim, I've been doing the same thing you're asking for two years
on a 105 Chrystler with no probs. Back a coouple of replies is
the diagram to make the isolator. Just like the one I made. Iff
you make your own, make sure it's enclosed in some kind of "Potting
Compound" to water proof it.
Ed
|
| 53.6 | I like a battery switch | TALLIS::KLOTZ | | Mon Jun 20 1988 15:23 | 38 |
| Hi,
I see two possible solutions to your question - both of which
have been used in larger boats and motor homes for years & are easy
to install:
1) The Guest Battery Isolator mentioned a few times above works
great. Almost all Motor homes have used this technique for over 15
years -- One battery was dedicated to the Engine, the other to the
operation of the "home" itself. If the lights etc.. drained the
operational battery you were sure that the vehical would start &
recharge both batteries. Almost fool proof. Yacht designs have
started using this approach in the past 5 years or so.
2) Guest also sells a Battery Switch. This allows you to put either
of two batteries into the circuit, (or both, or none at all).
The way this is normally used is one battery is selected to start
the engine (both are fine if both are charged), the both batteries
are switched in while running allowing them both to be topped off,
while stopped (or trolling etc..) the other battery is selected
to run the operation -- when your ready to start the engine again
switch in the other battery.
I have a 34' sport fisherman with 3 batteries and a switch set up
similar to that defined above. Normally I leave it set up with 1
battery to one engine/generator (also 1/2 the house keeping) the
other switch set up for two batteries to the other engine/generator
(& 1/2 the house keeping). If I stop off shore or spend the night
somewhere I switch the latter set to 1 of it's batteries. If the
battery runs down -- I simply switch to the un-used battery start
up & leave.
I find this takes a bit more thought than a diode Isolator; but,
in the long run is one less electrical part to fail & mentaly very
comforting to know I always have a fully charged battery to fall
back on.
Fair winds & all that,
Lou "Phanta Sea"
|
| 53.7 | Use switch AND isolation diodes. | BTO::JPETERS | John Peters, DTN 266-4391 | Tue Jun 21 1988 09:34 | 5 |
| re .6, you can use the select switch and the diode isolator at the
same time, getting the best of both worlds... The diodes also serve
to direct charging current to the battery that needs it the most.
J
|
| 53.8 | a couple of points | MSCSSE::BERENS | Alan Berens | Tue Jun 21 1988 09:51 | 12 |
| re .7:
>> The diodes also serve to direct charging current to the battery
>> that needs it the most.
The least charged battery gets the most charging current regardless of
whether a diode isolator is used or the batteries are simply connected
in parallel. One point about diode isolators: Many alternators (those
with internal or integral regulators) sense their output voltage at their
output. There is a significant voltage drop across a diode isolator
(usually about 0.7 volts). Unless the alternator output voltage is
raised, the batteries will not be fully charged.
|