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Lew Hodgett Lew Hodgett is offline
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First recorded activity by BoatBanter: Jul 2006
Posts: 348
Default Charger - House Bank Sizing


wrote

Thanks for the info. I forgot to mention,, yes I have four wet cell

6v
T-105s.

Another question...... is there a minimum Ah charge rate for a 3

step
charger? That is if I increase my house bank up to 600-800 Ah would

it
freak out a 30 amp charger if the bank was down to 30% of capacity??
Some where I heard the charger may sense the " emptyness" and

consider
it a short......


Basic rules of battery life straight from an old time Trojan
application engineer who had forgotten more about wet cell batteries
than the rest of us will ever learn.

T105s are happy when kept between 60%-65% and 90%.

For every AH hour you consume from a battery, you must replace it with
1.25AH.

A bank accepts recharge at an average of 15% of the AH capacity yes
the instantaneous can exceed 15%.

If you consume 100AH from your 400AH bank, you must replace it with
125AH at a 15% rate or about 60A which will require about 2 hours.

The above are the rules you live by with wet cells.

You can try all kinds of regulator hookus-pookus, but in the end, you
will live within the rules above.

Want to increase the time between recharge cycles or reduce recharge
time, increase the size of the battery bank.

A bigger bank with accept a higher recharge rate.

SFWIW, my boat is designed to have a house bank with 16, T105
batteries recharged from both solar and a Leece-Neville 4800.

As far as the regulator is concerned, it's only job it to control the
field current of the alternator which in turn controls the output of
the alternator.

Any decent regulator will have field current limit built into it to
protect both the regulator and the alternator.

I wouldn't sweat it if you have quality equipment.

Have fun.

Lew