Long-life batteries for ditch bag

[Dockhead]

I'm gradually gearing up for some long passages this summer -- 500 miles across Biscay -- hooray!

It requires more attention to safety equipment. I'm going to service the liferafts or possibly sell one and buy a new one.

And I'm finally putting together a proper ditch bag.

One thing which I thought ought to be in the ditch bag is a supply of batteries for flashlights (torches to those over here) and for the handheld VHF.

The handheld VHF will also be a navigation tool (I'm going to buy a SH HX851S) and the DSC function seems like an awfully good thing to have in a liferaft. I plan to keep it charged and hooked to my life vest when off shore, but obviously there is no way to charge it in the life raft. So I thought that a battery tray and AA batteries would be good things to have.

So what kind of AA batteries will stay fresh longer? Lithium? Or just keep a larger quantity of alkalaines, and rotate them so they are always fresh?

What do you guys do?

[hellosailor]

Eveready seems to be the sole maker of lithium primary AA cells. They're pricey, but the shelf stability and power output are also exceptional. They're the only thing I'd use for long-term storage.

And having seen a lot of leaky Duracells, and some (but way fewer) leaks from other brands, I'd consider stowing the batteries separately in ziploc or sealed baggies, and also putting silicon grease on the battery terminals/contacts in each device. I've found that ensures good contacts over the years.

Sanyo makes a NiMh battery under their "Enerloop" brand which is supposed to hold an 80% charge after a year on the shelf. That's incredible, also a one-of-a-kind. If you used those in the ditch bag, and rotated them out against others you used everyday, that could also be a good way to get some extra value out of the batteries.

With a VHF, unless it has a dedicated NiMh tray (and sometimes even then) you'll get better range from primary cells, simply because their voltage is higher by more than 1/2 volt per cell.

[Dockhead]

The SH radios have optional AA battery trays. I poked around in the net, and it looks like the Eveready lithiums have seven times the life of a regular alkalaines. Cool! A few packages of those ought to do it.

[barnakiel]

We use NiMHs for continuous duty and Lithiums for long term storage. I believe unless the boat goes to cold waters Alkalis are just as good.

b.

[CarlF]

Standard alkalines will still have usable power at 7-10 years. 85% after 4 years.

NiMh and NiCad discharge very quickly - 10% a month.

Lithium is very long lived but not clear it's worth the extra money versus carrying plenty of alkaline's (keep them cool and dry).

Carl

[Dockhead]

Originally Posted by CarlF

Standard alkalines will still have usable power at 7-10 years. 85% after 4 years.

NiMh and NiCad discharge very quickly - 10% a month.

Lithium is very long lived but not clear it's worth the extra money versus carrying plenty of alkaline's (keep them cool and dry).

Carl

You can buy 8 of them for only 15 bucks on Amazon. Compared to the cost of the other gear in the ditch bag, this is peanuts.

[noelex 77]

I would go with lithium. If for no other reason than alkaline batters can leak. In equipment that is rarely used the battery holder may be ruined before you realize there is a problem. In a liferaft you will not be able to use it even if you have new batteries available.