Can You Ever Have Too Much Reserve Electrical Power ?

[chadlaroche]

Can you ever have 2 many batteries or 2 much reserve capacity ?? My friend owns a golf cart shop and can get me as many 12v golf cart batts as I want ,rated 208 mins of reserve @ 25 amp draw for 25$ a piece. They are takeouts when they refurb carts. They all load test and hydro test out good so why not have 2000 minutes of capacity ??
I have 2 300 watt wind gens to keep them fed .....

chad

[rebel heart]

Except for the hassle of moving batteries around every few years to replace them and the weight I can't think of anything off the top of my head.

[Vasco]

The size of your battery bank will be limited by your capacity to charge them. Don't rely totally on your two wind generators.

[capn_billl]

Where is the shop? I would like a couple of extra. My experience with Batteries is this. Like the poster above you need to keep them charged and that means having charging capacity equal to usage. You have 50amps peak from the generators, and for continuos usage you'll want to be able to recharge bank in approx 1/5th time. Multiply load by time, I.E. you want to run the fridge and anchor light all night without running the generator. 5 amp fridge (run by inverter = 60amp DC/ duty cycle 30%)+ 1 amp lights = 21 amps time 10 hours = 210 amp hours * reserve 20% = 250AMP hours. Those are 80 amp hour batteries so 4 of them will power the example boat all night. a 100 amp charger will recharge them in approx 3-4 hours, your 2 * 25 amp windmills will need a stiff breeze all day. More batteries than that and you wont be able to keep them charged and they will fail.

[noelex 77]

With an offer of cheap batteries like that you would be mad not to take advantage of it.

Remember however batteries don’t make electricity. You still need to put back what you take out.

The ideal battery bank size is governed a lot by you usage and access to a mains supply.
With the availability of cheap batteries it is sensible to oversize the capacity, but the laws of diminishing returns start to set in so yes you can have too many batteries, where the weight and space taken up outweighs the advantages
.

[chadlaroche]

when I originally started this whole adventure I was trying to live without a fridge and use just a solar panel. just wanted to make sure i could make 3 days of cloud cover and still run lighting. Now its grown to double wind gens that I had hoped would cover my power needs.
Alas there is now a full time fridge , 2 tvs all kinds of electronic,computer chart plotters radar, wireless router ,fancy LED rope lighting( for the ladies ) inside besides reading lights , lights in the cockpit , 12v swimming pool light for night fishing etc,battery packs for tools,microwave ,crockpot ,rice steamer .And to think i originally was going to BBQ every night??
The boat came with a portable AC unit (the kind from Home Depot) which also dehumidifies. Not sure if its just too much power to run even with a small generator.Leave it or install it ?
I suppose I could add another alternator to the yanmar.... decisions decisions.Maybe I'll carry some extra to sell along the way .......

[barnakiel]

Our first house bank was 240 Ah,
we replaced this in NZ with a 170 Ah,
now I will go down to 110 Ah or so.

So, by half.

Meanwhile we also:

- doubled the solar bank (energy x 2),
- upgraded our alternator regulator (energy x 2),
- replaced nav lights with LEDs (energy/5),
- replaced laptops with netbooks (energy/2).

It is nice to have a lot of energy but the 'lot' is related to the consumption needs, not to an imaginary fixed number.

b.