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Old 06-25-2015, 04:52 AM   #22
Don New Zealand
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City: Christchurch
Join Date: Jun 2015
Posts: 7
I read some of the article and agree with what was written.

My first consideration is what are the battery makers charge specifications ?
included in this spec is the temperature / charge voltage graph, I haven't seen this talked about.

So where I live last night it was minus 5 C / 21F and in the summer it can be 35 C / 80 F

so I don't know where you keep your battery, most standard Flooded Lead Acid (FLA) likes to be at 15 C /60 F and any variation from this ideally requires 'temperature compensated charge regime' to get the most life.

So ask your supplier your battery's spec and if they don't know buy your battery elsewhere, I consider it a biggie.

So with this and a battery temperature monitoring regulator you have the chance to have much closer monitoring and with the result that your battery will last alot longer.

So what does it mean to you the end user if you have a well set up battery temperature compensated charging system ?

1)you can charge as fast as your battery can handle rather than nearest safe guess that a non temperature compensated system can deliver in worst case situation.
2) You have a much higher chance of not creating such a dangerous environment when your battery is in a hot engine room say 50C / 120F
3) Your battery will last longer and if your alternator has the grunt to do it then you will charge faster with no resultant loss of battery life.

The following is a little of topic but may still be relevant / useful

regarding a backup secondary voltage regulator in case of failure.

Piece of cake as the MC214 is set up to take a ford plug so buy a ford regulator and mount it beside your MC214 pull the plug off the mc214 and plug it directly onto the ford. Talk to your local sparky if you wish and they'll confirm what regulator will suit. I'd suggest you turn power off to the regulator before switching.


Checking your Flooded Lead Acid (FLA)

one way to check if your system is overcharging in rough seas without a meter is to touch the negative battery terminal if it feels warmer than ambient temperature and or you can smell rotten bananas it's probably overcharging. Another way is to monitor your electrolyte consumption, it should use a little each month, if this stops or increases , I'd be wondering why.
Best Flooded Lead Acid (FLA) battery tester of the lot including hundreds of dollar battery monitors with computer support I've found is a $15 temperature compensated hydrometer and a notebook, test monthly during your steam home when you're wondering how you'll spend the catch keep a 1.5 soda bottle full of fresh water next to you during testing in case any acid gets on your pants. I use a torch and mirror for the difficult to see cells.

re alternators with built in regulators and temperature compensation

I suspect the temperature compensation talked about in the article is both to protect the alternator and the battery as these regulators most probably originated from an automotive application where often the battery lives under the same bonnet in the engine compartment so reducing the voltage when the alternator and probably the battery gets hotter is usually a good idea, often after a run in summer the under bonnet hot soak temperature will often exceed 100 C / 212F.


a word on alternator RPM

All alternators have an optimum RPM
Faster equals more cooling (so you can work it harder without letting the smoke out) and higher charging at lower engine revs ( say 2kts trawl speed).
Faster equals more HP required to drive it.
Too much faster equals more chance of the alternator rotor winding letting go.
most alternators run happy as between 6 and 9 000 rpm
some bosch load handler 1.5+kw alternators will run alot faster
again consult the alternator supplier, often alternators are now supplied with rpm / output curves.


Most automotive alternators retrofitted into the marine environment last if they are only run as hard as 2/3 max output so keep your 90 A leece Neville at 60 A and it'll last till you're an old fart.

If I can keep my hand on the central laminated portion of the alternator while running for 1.5 seconds or more I'mn happy.

The Balmar are rated at full output continuous.


How to tell if your alternator pulley is slipping ?

When you stop the engine put your hand on it and compare it to the rest of the alternator, a lot hotter , it's probably slipping
If you want to know when your steaming then buy a infared temperature gun from ebay $20~30 measure the pulley (paint your measuring spot a matt colour or a piece of masking tape for accuracy and repeatability (google emistiivity and infared temperature measuring if interested why)
also these temp guns are handy as a quick check of your freezer temperature or each exhaust runner to see all pots running nice.
Any tighter than enough to stop slipping is using up bearing life on all the belt run.


A word on FLA Depth of Discharge (DOD)

Despite the glossy brochure to get maximum life / number of cycles don't discharge your FLA more than 30% from fully charged
(70 % remaining) so yes 2/3 of your battery is useless



When is a battery considered it's time to replace ?
that's up to you,
often this is when it is 80% or less of new condition.



A cool engine room is a happy engine room
and may your fish hold runneth over


Kind regards Donald
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