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Bob and Susan
Elite Nomad
Posts: 8813
Registered: 8-20-2003
Location: Mulege BCS on the BAY
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table
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Bob and Susan
Elite Nomad
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Registered: 8-20-2003
Location: Mulege BCS on the BAY
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comitan...6 105 ah 6 volt batteries is only...
3 105 ah 12 volt batteries
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MrBillM
Platinum Nomad
Posts: 21656
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Charge State ?
Most of the charts I've seen over the years for Lead-Antimony Batteries have read:
12.7 = 100% 12.5 = 75% 12.2 = 50% 12.0 = 25% (Resting Voltage)
When testing batteries of unknown or questionable condition, it is important to monitor the battery under a load. I've seen many batteries that will
appear to be at full charge and the voltage drops rapidly under any kind of a load.
[Edited on 6-15-2006 by MrBillM]
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Bob and Susan
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Location: Mulege BCS on the BAY
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12v times 150 amps = 1800 watts
a generator that produces 2500 watts all the time would only cost less than $300
Most generators come with 12v bulk charger capability...
Noise...run the charger while you're in town
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Bruce R Leech
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Location: Ensenada formerly Mulege
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sorry Dave I was just trying to help.
Bruce R Leech
Ensenada
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comitan
Ultra Nomad
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Location: La Paz
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Strive For The Ideal, But Deal With What\'s Real.
Every day is a new day, better than the day before.(from some song)
Lord, Keep your arm around my shoulder and your hand over my mouth.
“The sincere pursuit of truth requires you to entertain the possibility that everything you believe to be true may in fact be false”
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Sharksbaja
Elite Nomad
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Registered: 9-7-2004
Location: Newport, Mulege B.C.S.
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Inverter solution?
Using my 2500w inverter to power a 2-10 amp 110ac 12vdc battcharger I can keep my back-up 12v batt(batt) constantly charged when running or not. It
also charges a completely dead batt pretty fast. Of course there are tradeoffs.
You would still have to get a bigger alt but at low engine speed you should have all the dc you could use. Low RPMs plus you can have ample AC to
use for recharging or topping off his trailer set-up and the ability to draw off the vehicles batt reserves when necessary.
Here is the site I used set up my AC system: http://www.whistlergroup.com/faq-inverters-answers.asp
DON\'T SQUINT! Give yer eyes a break!
Try holding down [control] key and toggle the [+ and -] keys
Viva Mulege!
Nomads\' Sunsets
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Bruce R Leech
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Location: Ensenada formerly Mulege
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| Quote: | Originally posted by Sharksbaja
Using my 2500w inverter to power a 2-10 amp 110ac 12vdc battcharger I can keep my back-up 12v batt(batt) constantly charged when running or not. It
also charges a completely dead batt pretty fast. Of course there are tradeoffs.
[/url] |
Corky I don't understand using battery's and inverter to charge the Batterers. Have you invented perpetual motion
Bruce R Leech
Ensenada
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Sharksbaja
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No, it's inverted perpetual motion Actually Bruce my inverter keeps my spares
and moto batts charged via a cheap B& charger. My thinking was, Dave said he
neede more low RPM output. With an inverter you can literally drain what is in your vehicles batt if you need the DC while a at low RPM if need be.
It's much easier to run an AC cord from your inverter back to your trailer with a charger than huge DC cables. I assume that the trailer batts will be
isolated.
DON\'T SQUINT! Give yer eyes a break!
Try holding down [control] key and toggle the [+ and -] keys
Viva Mulege!
Nomads\' Sunsets
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jimgrms
Senior Nomad
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Registered: 9-30-2005
Location: oceanside ca
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Dave you would be better of just getting a port generator the price will be close and think of the fuel youl will save
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Bruce R Leech
Elite Nomad
Posts: 6796
Registered: 9-20-2004
Location: Ensenada formerly Mulege
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Dave check this site
http://www.sterling-power.com/htm/ar12vd.htm
Bruce R Leech
Ensenada
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Bruce R Leech
Elite Nomad
Posts: 6796
Registered: 9-20-2004
Location: Ensenada formerly Mulege
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Mood: A lot cooler than Mulege
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Split Charge Diodes
All boats have at least two battery banks - some have three. These tend to be the engine start battery, the domestic battery bank (please note that if
you join three or four batteries together in your domestic battery bank it is still one battery), and the bow thruster battery. Having introduced 2-3
battery banks onto your boat, the problem then is how do you charge them from one alternator source?
There are four various options employed by boat builders. Below are the options with a short explanation giving both the positive and negative
aspects.
1) Rotary switch. This system tends to be very dated, and is not very common on boats. It is recognisable as a large circular switch with four marked
positions on the switch. It is marked off, 1, 2 and both. The good side of this system is it is easy to install. The bad side is that it needs
constant human intervention to ensure it works. Failure to operate it correctly will result in all batteries being discharged or not being charged
correctly, and possible damage to the alternator. They also tend to suffer failure if large prolonged current is passed through them. The spring in
the switch can over-heat and loses its tension; this leads to a exponential break down of the switch and is manifested in heat. When these switches
fail they tend to melt the plastic case (if you are lucky). Simply check the temperature of the switch every so often by touching the back of the
switch - it should be cold.
2) Split charge relay. This system is both dated and extremely dangerous, and more than likely will make your boat fall short on CE requirements,
especially if a inverter is used or a bow thruster. The good side is, that it is easy to fit and requires no alterations to the standard engine
system, but merely connects the domestic battery bank to the engine battery via a relay, which is energised when the engine starts.
The bad side (and the very dangerous side) is that a relay is prone to vibration faults and over loading. Say for example you have a 70 amp relay on
your system and a 55 amp alternator, and you fit a 1500 watt inverter which can draw150 amps and one morning the domestic battery is flat. So you
start the engine to charge the domestic batteries, the 70 amp split charger relay will come on line to enable the alternator to charger the domestic
battery bank. Then you load your inverter to 150 amps, the 150 amps will not be drawn from the domestic battery because it is flat but be drawn from
the engine battery (which is full). That means you will draw 150 amps up the split charge cable and through the 70 amp relay. If you are lucky you
will destroy the relay, if you are not so lucky then you will set fire to the cross over cables, hence the dangerous aspect. The system must be
suitable for the purpose for which it is installed this is clearly not. Be warned about split charger systems using relays.
3) Split charge diodes: By using a set of diodes on a heat sink, one can ensure no back feed through the diode, thus ensuring that high currents from
other battery banks do not flow up the charge lines and cause a fire. This is the most common method by far employed round the world and is the
standard in the USA, for 3 reasons: safety, safety and safety.. However, all is far from perfect. The big down side with a split diode system is the
voltage drop across the diode (in the order of 0.8-1.2 volts), which dramatically reduces the charge rate of the alternator on average by about 70%.
However, do not forget the safety feature.
4) 0 volt-splitting systems: These are electronic devices using a control circuit and driving mosfets. The end result is a very low voltage drop
across the splitting system (in the order off 0.04 volts but no reverse current flow is permitted due to the operation of the mosfets. A good analogy
is the safety of the split charge diode with the performance of a split relay. However, at a much higher financial cost, this system is ideal where a
vehicle or engine is being used and the alternator cannot be altered for warranty or other reasons. However on standard marine engines where a
advanced regulator can be used much better to employ the lower cost diode with a advanced regulator, (see performance below).
Conclusion:
Test 1: From fig1 we can see the voltage drop across different splitting systems. This directly relates to the ability to charge the batteries, the
larger the voltage drop across the device, the less effective the batteries charge.
Test 2 shows the clear advantage of using advanced regulators in conjunction with a conventional split charge diode. The advanced regulator
automatically compensates for the voltage drop across the diode, plus the high charger 4-step program increases the charge rate even further. The
above tests were on a 300 amp hour battery bank, but can easily be extrapolated to 400 amp plus.
The ideal system is clearly a standard low cost split charge diode (for safety and cost) and an advanced regulator on the alternator to compensate for
the diode faults and charge at the constant current charging curves. This not only charges 2-3 times faster (on a good installation, but much higher
on a bad one) but puts about 100% more useful power into the batteries.
For a twin alternator system, the ideal system is: on the largest alternator, fit direct to the domestic battery bank and attach an Advanced Regulator
to that alternator. On the smallest alternator split this with a split charge diode between the engine battery and the domestic (and any other battery
bank) and add another advanced regulator to it. This gives maximum charge rate to the domestic batteries.
Bruce R Leech
Ensenada
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Bruce R Leech
Elite Nomad
Posts: 6796
Registered: 9-20-2004
Location: Ensenada formerly Mulege
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chart
Bruce R Leech
Ensenada
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Bruce R Leech
Elite Nomad
Posts: 6796
Registered: 9-20-2004
Location: Ensenada formerly Mulege
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Mood: A lot cooler than Mulege
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chart 2
Bruce R Leech
Ensenada
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Bruce R Leech
Elite Nomad
Posts: 6796
Registered: 9-20-2004
Location: Ensenada formerly Mulege
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Mood: A lot cooler than Mulege
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photo
Bruce R Leech
Ensenada
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Bruce R Leech
Elite Nomad
Posts: 6796
Registered: 9-20-2004
Location: Ensenada formerly Mulege
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HOW TO SIZE AND USE YOUR BATTERY BANK
Here is another good site that might help you
http://www.glacierbay.com/1batcrg.asp
Bruce R Leech
Ensenada
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Bruce R Leech
Elite Nomad
Posts: 6796
Registered: 9-20-2004
Location: Ensenada formerly Mulege
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Mood: A lot cooler than Mulege
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Dave there is a good book that I bought many years ago that has been invaluable to me over the years. it has a wealth of info for a small book. I
lived on 12 volts for a long time and I have tried everything.
Living on 12 Volts with Ample Power
http://www.amplepower.com/products/living/index.html
Bruce R Leech
Ensenada
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Sharksbaja
Elite Nomad
Posts: 5814
Registered: 9-7-2004
Location: Newport, Mulege B.C.S.
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Confusion says:
What???? You didn't like my ac to dc to ac to dc scheme? Seems silly donut.
Ok, so I'm not a rocket scientist or electrician but I' m trying to sort this out;
40 amp charger 40 amp charger requires 5.91 continuous ac amps .
For 100 amp dc starting mode it draws 11.29 ac amps.
Using this formula:
P = V * I
P is power in Watts
V is voltage in Volts
I is current in Amps
Watts = Volts times Amps
12v X 40a = 480 watts
12v X 100a = 1200 watts
-----
Given the 2500 watt inverter puts out a constant 20.8 amps it seems I would have a surplus of watts at this rate.
So it seems I have stumbled onto perpetual energy.
Get more out than you put in??
NOT!
Now I'm confused
DON\'T SQUINT! Give yer eyes a break!
Try holding down [control] key and toggle the [+ and -] keys
Viva Mulege!
Nomads\' Sunsets
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Bruce R Leech
Elite Nomad
Posts: 6796
Registered: 9-20-2004
Location: Ensenada formerly Mulege
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Mood: A lot cooler than Mulege
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the thing is that the manufacture lies about the 100 amp output so it makes it seem to good to be true and it is 
Bruce R Leech
Ensenada
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MrBillM
Platinum Nomad
Posts: 21656
Registered: 8-20-2003
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Too Good to be True
If you purchase one of those High-Output Alternators, simply take it to one of the numerous Auto Parts Stores or Garages that have a test bench and
pay them to test the maximum output. Knowing for certain is worth the few bucks spent. The only challenge at some of those auto parts stores will be
finding someone who knows what they're doing.
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