Lipo/Lifepo4 in damp weather

[gensem]

I was questioned by a friend today about Lithium batteries for bicycle and hot weather.
He lives in Rio de Janeiro wich has a very hot and damp weather... He was telling me that lead has a much longer life in these condition and he is not going to use lipoly.
I mean I never heard anyone complaining when living in a bay area, granted Rio´s weather is really wet.
Are his complains feasible? Would lifepo4 behave like lipo?


tks

 

[ohzee]

We have quite a few riders in Arizona and I know it gets 120's F in the summer there.

I would be more concerned about the damp then heat myself..

 

[gensem]

title changed from "in hot weather" to "in damp weather"
because damp is the relevant factor.

 

[wesnewell]

The average temp range in Rio is about 65F to 85F. Not at all what I'd consider hot. Lead would perform better there than in colder climates, but so will lithium. And there's no way it will outperform or outlast lithium by a long shot. Humidity shouldn't have any affect on either since most lead is sealed and all lipo is.

 

[Drunkskunk]

Damp? can't get much damper than raining. The only risk from "damp" is a short because you haven't waterproofed well enough for the conditions, and don't have a fuse. Under those conditions, Lipo might short out, over heat, and burn.

But

SLA might also over heat, vent hydrogen, explode spewing acid all over yourself and any innocent bystanders, then burn. Not as violently, but who cares when your nuts are soaked in flesh eating battery acid.

Not likely. But then a battery fire from riding in the rain isn't very likely either, Unless you have open connectors pointing at the sky to catch as much rain as possible and pouring salt in there as well

 

[dogman dan]

I remember a thread a few years back where a guy wrecked a lifepo4 battery fast by letting salt spray from melting snow get into the battery compartment. He had salt buildup all over the battery bms and wiring.

So, something similar could happen if the bike was ridden in the area very close to the ocean enough. One issue is that a bms can't be completely smothered in waterproof bags or boxes in the hotter climates. I'd say a good box for the cells, then put the bms into a heat sink box similar to a controller, and seal it up. Any water that doesn't bother the controller wouldn't bother the bms if it's in a similar enclosure. The battery itself won't give a damn, in its water tight box. The cells don't need vents, but a way to let out excess gas could be a good design feature. Like, just in case lipo got too hot, gas woud blow out a rubber plug or even just taped over vent hole.

 

[RTLSHIP]

70 degrees F is the ideal temp for SLA. Lithium types do better in warm than super-cold. As for dampness, you probably don't want to get any battery wet. But I've never heard of humidity problems with lithium. Dampness can definitely affect
a controller.

 

[sangesf]

Humidity has NO effect on any battery...
It's high heat and low cold..
High heat = more power / less cycles
Low cold = less power / more cycles

The opposite holds true for motors...
Cold = more efficiency.
Warm = less efficiency.

 

[dogman dan]

Exactly. But a salt spray could harm a controller, bms, or whatever. Nothing metal lasts at the beach unless it's brass. Obviously you don't want a tire spraying down your wiring or cell connections, but that would apply to sla or any chemistry equally.

It should be a good climate for happy sla, but that would make it a good climate for happy lithium too.