Best batteries for $2k budget

[Adventuresail]

This alternator will just be used to keep my start battery charged.

[sailorboy1]

Originally Posted by sailr69

60 amp alternator is far too short for charging that large battery bank. at best you will only get maybe 55 amps from the alternator. you will be running the engine hours and hours to keep it charged. the other charging bits can at best just keep up with your usage. out of balance system

An alternator, even a 60a in this case, is just part of the charging profile of a boat with solar. But, since most "standard" batteries only accept their max charging current for a short time the difference for most people to get fully charged with a 60a alternator and 100a (or more) is minor. Probably not worth the $$$$$ really to upgrade the alternator really IMO.

[Adventuresail]

Honestly, im not that concerned about alternator charging either. I would only ever start our propulsion engine just for charging if my solar array wasnt working. I can certainly see its appeal for other people and if i had a bigger budget it might be something i would add but for now its alot lower on the list than maxing out on solar panels which we have a large amount of space for.

[Dockhead]

Originally Posted by Adventuresail

Honestly, im not that concerned about alternator charging either. I would only ever start our propulsion engine just for charging if my solar array wasnt working. I can certainly see its appeal for other people and if i had a bigger budget it might be something i would add but for now its alot lower on the list than maxing out on solar panels which we have a large amount of space for.

A lot of us find it really useful to have abundant power whenever the main engine is running, even if we don't much run the engine solely for battery charging.

I have a heavy duty diesel generator, yet I believe I produce more kwh per season with the school bus alternator.

[kmacdonald]

Originally Posted by sailorboy1

An alternator, even a 60a in this case, is just part of the charging profile of a boat with solar. But, since most "standard" batteries only accept their max charging current for a short time the difference for most people to get fully charged with a 60a alternator and 100a (or more) is minor. Probably not worth the $$$$$ really to upgrade the alternator really IMO.

Yes, that's exactly correct. Only lithium require high output alternators with external controllers. It's kind of a waste otherwise.

[NYSail]

I am slowly building my boats charging / power system. Got my boat with a dumb 80 amp alt and 2 agm 4d lifelines. Immediately put in a balmar 150 amp alt with an mc614 regulated..... downgraded the alt and also put on a serpentine belt. Got rid of the 4ds And bought 4 Trojan t125s and then programmed the alt to the parameters of my batteries.... you just can’t use factory settings.. also I have a Blue seas acr for charging my starter battery. This set up assured me that if I have to motor anywhere for 3 hours my batteries are going to get an excellent charge. This set up usually gets me 3 full days bringing batteries to 50%. Now I have started on my solar..... just jumped in with a 175 watt panel while I redo canvas and frames at which point I hope to have 500+ watts. Also I do have a Honda generator as back up But will eventually fix / reinstall my genset. We may never do an ocean passage however enjoy the independence a good power set up will get you.

Good luck!

[kmacdonald]

It takes longer to put 200 Ah back in a 800 Ah bank than a 600 Ah bank. Don't oversize the bank for longevity sake. Large banks will run at PSOC more than smaller banks defeating the gains of lower DOD cycling.

[Dockhead]

Originally Posted by kmacdonald

It takes longer to put 200 Ah back in a 800 Ah bank than a 600 Ah bank. Don't oversize the bank for longevity sake. Large banks will run at PSOC more than smaller banks defeating the gains of lower DOD cycling.

Not correct. Where do you get that? It's the other way around. During absorption phase the bigger the bank, the faster you can put in a given number of amp-hours. In bulk it's the same thing unless you are anyway limited by charger capacity. In any case, you can use a larger charger with a larger bank.

[kmacdonald]

Due to the limited time some solar charge controllers remain in bulk and absorption mode, don't be afraid to increase the "float" voltage to 13.8 to 14 volts. "Float" on a solar charge controller can be set differently than a shore power charger that charges 24 X 7.

[FAST FRED]

I think you are looking in the wrong direction.

For an auto pilot a small tiller pilot hooked to a trim tab works as will the classic Aires system, that needs no electric..

The reefer could be either a good well insulated box with eutetic plates or a propane unit that needs no electric.

Propane is very good for the range , oven and broiler, although some folks prefer kerosene as 5 gal will usually last a year.

Why bother with big batt expenses from a system that is complex and going down hill from day 1?

[kmacdonald]

Originally Posted by Dockhead

Not correct. Where do you get that? It's the other way around. During absorption phase the bigger the bank, the faster you can put in a given number of amp-hours. In bulk it's the same thing unless you are anyway limited by charger capacity. In any case, you can use a larger charger with a larger bank.

BS. It take much longer to put in the final 20% charge and the larger bank will have more Ah above 80% SOC to fill. If you like to abuse your batteries like most people and operate in the 50 to 80% SOC range you are correct but otherwise you are dead wrong. It's a common misunderstanding leading to gourmet charging systems and batteries. Marketing at it's best. Absorption phase won't get your batteries anywhere near 100% SOC. It takes a long time to fill a battery and it is limited to acceptance rate of the battery.

[Q Xopa]

Originally Posted by Dockhead

A lot of us find it really useful to have abundant power whenever the main engine is running, even if we don't much run the engine solely for battery charging.

I have a heavy duty diesel generator, yet I believe I produce more kwh per season with the school bus alternator.

Im with ya.

IMHO they are great.

It's obviously not 'free' but whe the motor is running its pretty cheap power.

Simple, rugged, cheap, parts and expertise easy to find, power.

Downsides, bigger frame so got to have a bit more space. Also need to be up for a bit of DIY 'fun',

New 200A, 12v units around $220. Not the same quality as a specialised marine grade. I bought an extra for a spare.

New 8 rib Alternator pulley $30

Balmar 614 Ext reg $330.

$580 +

Some 'DIY Fabrication' making, modifying, or getting your local machine shop to knock up a- crank pulley, water pump pulley, mount, spacers and adjuster.

Do external reg conversion.

This is not as scary as most think.

[ccannan]

Originally Posted by Gerrit Coetzee

I am switching to Super Capacitor Battery. 3,5kw Weighs 45kg 1,000,000 cycles. Charge to full in short times, and can discharge to 99%. 48v delivery. Built in converter to 110v/220v and built in MPPT.
Size 20cm x 45cm x 60cm
Note that I mentioned battery, not batteries.
One battery delivering 3,5kw!!



Costs between $2000 - $3000 depending where it is sourced from.

I'm very interested about this technology. Please provide more information. It looks like the pictured SC is made by Deutsche Tec, but I find nothing about them on the internet. Are you intending on replacing your house battery bank with a SC module or will it complement your existing house battery bank? How will you recharge your SC module?

[sailorboy1]

Originally Posted by kmacdonald

It takes longer to put 200 Ah back in a 800 Ah bank than a 600 Ah bank. Don't oversize the bank for longevity sake. Large banks will run at PSOC more than smaller banks defeating the gains of lower DOD cycling.

I join in saying this is wrong far as it is practical be a cruiser to measure "longer". AHs are AHs and not the same as fully charging. which I bet either takes basically 5 hours for either. But I don't care to debate it.

[kmacdonald]

Originally Posted by sailorboy1

I join in saying this is wrong far as it is practical be a cruiser to measure "longer". AHs are AHs and not the same as fully charging. which I bet either takes basically 5 hours for either. But I don't care to debate it.

I known, it's splitting hairs and technical to boot. Where have you been? You still posting the budget?