[PUP] Energy resource management

[John Marshall]

Can you drive the 300a model off a single belt? Not sure what my  
current drive belt is called, but its an inch or so wide. If so, it  
might be possible to replace my current Leece-Neville 170A model with  
the 300A. Tks for heads up on the spec sheet. I'm guessing a used unit  
might be floating around out there somewhere.

John
On Dec 7, 2008, at 5:21 PM, 2elnav at netbistro.com wrote:

> A point of clarification. I was only thinking of solar as a trickle  
> charge
> to top up the battery bank in float stage. There is no way you  can
> achieve anywhere near a good bulk rate with solar. The boat cannot  
> support
> enough square footage area of solar panels.
>
> There is another good reason for the split bank concept.  If you  
> cannot
> provide enough charge current to get above the 0.2 X battery  
> capacity A-H
> capacity then reducing the bank size while bulk charging may be the  
> only
> way. Leece-Neville use to make a wonderful 300 Amp @ 24V alternator.  
> They
> still provide data sheets on the Prestolite website but the product  
> line
> (VLF)  is now listed as being discontinued.
> I have one of these monsters and I know of a few more surplus units.
> You may also be able to find  one of the bigger rebuild shops  with  
> reman
> units in stock.
> However, there is another way. The trucking industry uses 160 amp
> Leece-Neville alternators - at least on the older (pre 2000) trucks.  
> Some
> clever mounting using jack shafts and pillow bearings can provide  
> you with
> a 2X 150A = 300 Amp charging plant that can be driven by a coaxial  
> flex
> coupling and drive shaft.
>
> John also wrote:
>> "That's ~8kw, net of house loads and charger efficiency losses --
>> probably need 10KW with only light house loads on the DC system  
>> just to
>> charge".
>
> REPLY
> Quite true, but that is still only about 15 HP of power from the  
> engine.
> If you have a 25HP or larger wing engine, its quite doable.
>
> regards
> Arild
>
>
> ---------------------- original message --------------------------
>
>> There is a downside to long, slow charging, at least when it comes to
>> AGM batteries, which would be a big issue with solar. Lifeline (and I
>> assume this applies to all low-resistance AGM's) is very specific  
>> that
>> for repetitive charging, you should charge at a rate of 0.2 x battery
>> bank capacity in amp/hours, otherwise you'll lose capacity over time.
>>
>> So you get clobbered on both ends if you aren't careful. Here's the
>> link:
>>
>> http://www.lifelinebatteries.com/manual.pdf
>>
>> In my case, when I parallel all 12 batteries, I've got 1530 amp/hours
>> capacity at 24v (charge relays automatically connect thruster
>> batteries to house bank during charge). Per Lifeline, I should have  
>> an
>> initial NET (after house loads) charge current of AT LEAST 306 amps,
>> with a maximum of 5x capacity -- a staggering 7650amps (you really
>> can't charge these batteries too fast). Between my Xantrex 4KW
>> inverter/charger and two additional Mastervolt chargers (each rated  
>> at
>> 50amps at 24v), I can't get above 220 amps at 24v.
>>
>> Guess I need to add yet another 100 amp at 24v charger. Good news is
>> that its more load for the genset (makes it more efficient) and
>> shortens bulk recharge time.
>>
>> But that said, I've never met anyone who could achieve a 320amp  
>> charge
>> rate at 24v on their boat (640 amps at the usual 12v). That's ~8kw,
>> net of house loads and charger efficiency losses -- probably need  
>> 10KW
>> with only light house loads on the DC system just to charge.
>>
>> It also says that bringing the house bank back up with my engine-
>> driven 170amp at 24v alternator is a recipe for short battery life  
>> and
>> short alternator life. Which says I have to do the bulk charge with
>> the Genset even if I'm underway. Not many people think of doing that
>> when pulling out of an anchorage with a half-depleted house bank.
>>
>> And clearly, if you go to solar charging, stick with old-fashioned
>> flooded cell batteries. You can't get enough amperage for a large AGM
>> bank unless your whole boat is covered in solar cells. Even then...
>>
>> Arild is right... energy management gets to be a huge deal if you  
>> need
>> a lot of power. And the idea of split battery banks sounds better all
>> the time.
>>
>> John Marshall
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