Batteries?

[john61ct]

Only if you have replacement power available on demand, or running out occasionally is NBD.

Solar only with medical necessities would dictate a decent buffer for poor conditions.

And only if you don't mind replacing the bank more frequently

and usually travel near places where your batts are readily available, since you'd be spending a higher proportion of bank lifetime at a higher risk of sudden unexpected failure.

For a long circumnavigation with lead, I'd design for the usual 50% DoD cycling.

All depends on circumstances, there are few rules that fit all.

[CatNewBee]

I guess, everything was said about GEL, AGM, Wet lead acids...

there are 2 more options for long lasting batteries - lead crystal and of course Lithium. I would take the LiFeYPO4, small, light, heavy duty, deep dischargeable, plenty of amps, quick charge, 5000+ cycles.

[kmacdonald]

Originally Posted by CatNewBee

I guess, everything was said about GEL, AGM, Wet lead acids...

there are 2 more options for long lasting batteries - lead crystal and of course Lithium. I would take the LiFeYPO4, small, light, heavy duty, deep dischargeable, plenty of amps, quick charge, 5000+ cycles.

I don't think lithium is suitable for the vast majority of cruisers. One charging or discharging mistake and they are ruined. The average cruiser needs a FOOLPROOF solution. To accomplish that with lithium is complex, not very robust, and cost prohibitive.

[skipmac]

Originally Posted by kmacdonald

I don't think lithium is suitable for the vast majority of cruisers. One charging or discharging mistake and they are ruined. The average cruiser needs a FOOLPROOF solution. To accomplish that with lithium is complex, not very robust, and cost prohibitive.

My position exactly. I find the learning curve and the requirements to keep LiFEPO happy and avoid killing them more than I care to deal with for now, and this is coming from a guy with a degree in electrical engineering.

The possibility of a minor screw up toasting a few thousand dollars worth of batteries is just not something I'm ready to accept. I'm sure I could figure out how to run a LiFEPO setup but I've got too many other things on my plate. The final bit, the requirements to modify and/or upgrade the charging system for another boat buck or three.

[kmacdonald]

Originally Posted by skipmac

My position exactly. I find the learning curve and the requirements to keep LiFEPO happy and avoid killing them more than I care to deal with for now, and this is coming from a guy with a degree in electrical engineering.

The possibility of a minor screw up toasting a few thousand dollars worth of batteries is just not something I'm ready to accept. I'm sure I could figure out how to run a LiFEPO setup but I've got too many other things on my plate. The final bit, the requirements to modify and/or upgrade the charging system for another boat buck or three.

Exactly. I have been using a 20 Ah lithium for four years but only charge it with solar so it's a simple setup. It's only a $150 battery so I don't mind taking the risk. I wouldn't do it with a large lithium bank that cost thousands, or even $500 for that matter.

[skipmac]

Originally Posted by kmacdonald

Exactly. I have been using a 20 Ah lithium for four years but only charge it with solar so it's a simple setup. It's only a $150 battery so I don't mind taking the risk. I wouldn't do it with a large lithium bank that cost thousands, or even $500 for that matter.

I'm using 6, 6V golf cart batteries. Gives me about 650 amp hours total capacity, about 300 usable. More than enough for all my goodies and only have about $500 invested. Almost 10 years old and still working but might be about time to get new ones.

[kmacdonald]

When I get a bigger boat with a refrigerator I will use 6V golf cart batteries. Best bank for the buck IMHO. Lithium has all the best attributes a cruiser is looking for except fault tolerance. Just too unforgiving. I'm sure I will forget to turn the solar off one day and ruin my small lithium but it won't break the bank.

[john61ct]

Please don't bring so-called "lead crystal" into the picture, unless you manage to find some objective data from trusted sources that demonstrate it's not just a scam.

[zboss]

Originally Posted by john61ct

Sorry, absolute bunk.

If you were talking LFP, yes.

But within the lead family, size in AH, State of Charge and State of Health are critical for the ability to deliver high C-rate discharge current, AGM won't be of significant advantage.

Here is my logic.

They take heavy discharges, such as windlass and engine without damage while maintaining a more consistent voltage during those short periods (or longer if using a heavy inverter load). If you have electronics that are already close to that allowable 3% voltage drop due to wiring or higher draw at start up, you are only shortening those electronics lifespan further when those FLA batteries are unable to deliver that voltage, resulting in regularly occurring brown outs. Look at when the lights flicker when you use the SSB or turn on a pump. That can’t be good for anything that shares that power.

Why not have a battery that is able to deliver large draws and maintain that voltage?

[CatNewBee]

Originally Posted by john61ct

Please don't bring so-called "lead crystal" into the picture, unless you manage to find some objective data from trusted sources that demonstrate it's not just a scam.

... There are some people out there that have them in RV's and like them, I personally have no experience with them yet, however - they are heavily used in UPS solution for railway traffic lights and telecommunication containers, where maintenance-free operations for years is required.

They claim this batteries are performance wise similar to AGM, but deeper dis-chargeable with no damage. I guess the truth is somewhere in the middle.

[frozenhawaiian]

honesty my house bank are duracell batteries from the local sams club that have been just fine

[john61ct]

Yes best value on the planet for deep cycling lead at under one USD per AH, actually a Deka product, also sold by Batteries+

Only exception might be LFP for those that get 15+ years out of them, but such high up-front costs makes that risky.

[CatNewBee]

I am on the track for LFP, Its just the power when used with an inverter.
You need a 4 times larger lead acid battery bank to have this Amperage without a damage to the cells and voltage drops.

They also charge ways faster than any Lead Acid bank.

It is not only the weight and the long lasting of the bank / cycles...

[skipmac]

Originally Posted by john61ct

Yes best value on the planet for deep cycling lead at under one USD per AH, actually a Deka product, also sold by Batteries+

Only exception might be LFP for those that get 15+ years out of them, but such high up-front costs makes that risky.

And that sums up my feelings onLiFePO pretty well. The most usable amp hours for the money unless you screw up, then you're way, way underwater on the costs.

I do like the greater usable capacity for a smaller, lighter bank but just not willing to risk the cost and deal with the care and feeding required.

[skipmac]

Originally Posted by CatNewBee

I am on the track for LFP, Its just the power when used with an inverter.
You need a 4 times larger lead acid battery bank to have this Amperage without a damage to the cells and voltage drops.

They also charge ways faster than any Lead Acid bank.

It is not only the weight and the long lasting of the bank / cycles...

I agree with all of your reasons except for cell damage with high current draw. I have not seen a problem with standard FLA batteries under high current demands. I have a 2000 W inverter and pull 150 amps or more from my 6X6V FLA golf batteries. They're nine years old and not dead yet.