boat batteries

[anabel]

Forum members with an interest in boat batteries might find this site interesting.
http://www.esa.int/esaCP/SEMX4DWJD1E_Improving_0.html

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[Dave1258]

http://www.esa.int/esaCP/SEMX4DWJD1E_Improving_0.html

<hr width=100% size=1> Experience is something you don't get until just after you need it.

 

[ashley]

Lithium ion batteries lovely!
They're only just affordable as 1ah in my phone.
God knows when i can afford a few hundred amps

<hr width=100% size=1>Live life to the fullest... think of all the people on the Titanic who passed up chocolate dessert.

 

[William_H]

Disn't see any reference to Lithium Ion batteries on that sight. Lithium ion batteries have very critical charge voltage requirements as a mobile phone battery and I have not heard of them as large batteries. SAFT have made Nichel Cadmium batteries for aerospace for many years. In fact I have 10 SAFT cells reject from a helicopter in my boat. The advantages are lighter weight longer life, a maintenance of votage until almost discharged and ability to deliver and be charged at very large currents. Capacities tend to be much smaller than similar sized lead acid but you can rely on getting 80% of the rated capacity out even on an old battery. One of the maintenance requirements is to completely flatten each cell and leave shorted for some hours before recharging. My guess is that unless I am missing something this is the kind of battery being used in the Vendee Globe. will

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[Talbot]

Hope they are not Lithium ion cause they really dont mix very well with salt water! - something people should consider with digital cameras/ telephones mp3 players etc.

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[BrendanS]

A hypothetical problem rather than a real one for everday use. The battery packs contain circuitry to detect shorting, and are designed to fail the battery safely by isolating the power strips

The fact that they are lithium isn't an issue, the lithium is present in a salt state, not as pure lithium, so won't explode on contact with water. The danger is the amount of energy stored in them, hence the safety circuitry.

<hr width=100% size=1>Me transmitte sursum, caledoni

 

[Evadne]

True up to a point, the in-built chip will prevent problems due to shorting or overcharging, although unlike Lithium primary cells I don't think they don't produce much heat on discharge; but a little known fact I came across is that they can self-ignite at a temperature of 150 celcius. This would make them a real hazard in case of a minor fire nearby.

They also have, like any other rechargeable, a finite number of recharge cycles so will wear out just like anything else.

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[Trevethan]

AT a conference recently I met a chap who was talking about rechargable zinc batteries for use in hybrid vehicle. (He promised me a couple for teh boat to try out, but they never came)

Apparently its a dry technology and offers plenty of amps for teh buck, but am waiting for the proof.

They apparently can use a regular lead-acid charging regime too.

To me it sounds like a much better system than the complicated Lil-ion system, expecially in a marine environment.

Nick



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[ashley]

I'm pretty sure they're Lithium-ion batteries, could be Ni-Cads though