Best battery type > Freezing temperatures

[zuzullo]

These are the only 2 batteries available at my town:



Why would I go for a GEL battery considering that both claim a 20h constant power deliver?
Here is my purpose:

- Powering: laptop, music (a lot), coffee machine, lights (LEDs), electronics, etc.
- Its a sailboat with no engine. Small outboard (Petrol) only for docking. (can only charge batteries at the marina)
- I live in the arctic with temperatures around -5°C (23°F) for 5month/year
- Sometimes the battery has to remain fully discharged for 1 of 2 days until I get back to shore.

[PaulfromNWOnt]

It's a safe statement to say battery acid doesn't freeze. I've seen frozen batteries, but thos have all been extreme circumstances.

Fully discharging a battery is hard on it. Leaving it in that state doesn't help. If you plan on using that much power, then increase the size of your bank. A bunch of batteries wired in parallel will have a lower replacement cost in the long run if you don't kill them then a single battery that you hammer on.

That being said, gel cells seem a little more tolerant to abuse. It would be up to you to determine if that tolerance is worth the premium.

[zuzullo]

Originally Posted by PaulfromNWOnt

It's a safe statement to say battery acid doesn't freeze. I've seen frozen batteries, but thos have all been extreme circumstances.

Fully discharging a battery is hard on it. Leaving it in that state doesn't help. If you plan on using that much power, then increase the size of your bank. A bunch of batteries wired in parallel will have a lower replacement cost in the long run if you don't kill them then a single battery that you hammer on.

That being said, gel cells seem a little more tolerant to abuse. It would be up to you to determine if that tolerance is worth the premium.

At, roughly, what temperature do GEL batteries freeze?

I dont know if what I have been doing to my, current cheapo, battery is called "fully discharge". Sometimes I use it until it fails and then I charge it. I try to get it on charge as soon as possible but it can take a day until I do so. You mean that I should avoid doing this, right? Then I need something to control when to stop. What is the percentage that one should stop draining a battery?

[mitiempo]

50%

[falconev]

you need a lithium battery
that was an easy question to answer...
Andy
LithiumMoto

[PaulfromNWOnt]

A battery in reasonable condition shouldn't freeze above -40 C (the battery in my truck is not in reasonable condition and didn't freeze at -42 C). If you are regularly discharging this battery below 11.6 volts, you are severely limiting it's lifespan. Most 12v batteries are considered discharged at around 11.85v, and should be recharged.

As I mentioned before, increasing the capacity of your bank will increase it's longevity, but you still can't neglect them and hope they'll last. You may want to consider some form of auxiliary charging system (solar/wind) to help prolong the life of the battery bank.

[zuzullo]

Originally Posted by falconev

you need a lithium battery
that was an easy question to answer...
Andy
LithiumMoto

Oh, I didnt thought of that. Do you know any link with prices for that?

[mitiempo]

Use a standard flooded battery but keep it charged.