I leave them in, but charge them for an hour or 2 each 3-4 weeks... and it is freaking cold up here...

I use to leave mine in all winter but would have to replace one every summer. Now I pull them and put them on a $5 Dollar store trickle charger and have had them for 3 years no issues.

The key I believe is to keep them charged and maintained.

Extreme cold temps will freeze and ruin a battery that is low on charge. If its charged, it will be fine.

Pull them the first winter, toss them the second. Batteries are cheap. Stuck on the water isn't. I've had two shorted-plate incidents in the last decade. No issues now that they get replaced every two years.

Batteries will lose 5% of their charge every month just sitting there. The charge lost means that the plates become sulfated. This bond becomes thicker, and harder to release the longer it sits. So, if you leave your batteries all winter, then recharge, you will never have 100% of the amp hours the battery can support ever again.

So they may work with a recharge, but they will not be 100%.

Always use a battery tender. They are soooo cheap compared to batteries, it makes no sense to replace. We sell expensive battery chargers to backup generator OEM's all over on the basis of making their batteries last longer. They are paying for them for a reason.

This is what I do,have not been stranded because of a battery issue in 9 years.....

I leave them in but keep them charged. I have also found that topping them off with electrolyte as opposed to water makes them last longer.

I leave them in and toss a charger on them for a day or two at 2 amps every 4-6wks. I dont have any problems with them and run them for 3-4 yrs. Although lately the boat has been inside and the heater seems to stay on.. something to do with rebuilding motors... something like that..

Dick

What sort of battery tender










What sort of battery tender (brand-model) do you recomend for Optima batteries.




9

Why use a battery tender and not the on-board charger powered by the shore power cord?