Maintenance
Looking after your batteries can double their lifetime! Here's some do's and don'ts for Lead Acid batteries:
Never
- Run your batteries down to below 12.2v
Always
- Always check there's enough liquid in the cells - open them up every so often and check that the liquid is about 2-3mm below the hole you're looking through.
- Use distilled (not tap, or even filtered) water to top up your batteries. Offer to defrost someone's freezer and use all the ice that's stuck around it (yes, melt it first in a clean container!)
Safety
Lead Acid (bog standard car battery type) batteries are the most dangerous bits of your 12v electrical system. Check out the following and you should survive :-)
DON'T :
- hurt your back when you pick up heavy batteries
- smash your toes when you drop heavy batteries
- put anything metal on top of your batteries. If the two terminals are connected then the battery will short circuit. This will lead to lots of scary sparks, and the battery may explode! If you are really unlucky the metal will be welded onto the terminals and you won't be able to knock it off.
DO
- be careful of the liquid inside Lead Acid batteries - it's strong acid and will burn you and your clothes!
Batteries
It's false economy to buy a tractor or car battery. If you run it down (deep discharge it), it will be only good for keeping your boat down in the water. Buy a 'Leisure' battery (I know), for more money; it will survive a few discharges. 'Marine' batteries are better, and more expensive still. Best, buy a circuit that will isolate your battery if the voltage goes below 12v or 11.8v. Leaving lights on has cost me, truly, >300 quid. You might consider lithium batteries, as used in laptops, which are getting more affordable. Try to recycle; don't sell to scrappies, they pour the acid out (into the watercourse).