12v Li-Ion battery packs

[josephmoore]

Thoughts on a flexible and light weight option for some electricity on board - has anyone got any experience of the Chinese Li-Ion battery packs? Example: http://www.ebay.co.uk/itm/331198889414

At 9.8Ah (though I love the capacity disclaimer in the description) one or two would cover all I'd ever use and I could easily pop it in my bag to recharge at home. The alternative is perhaps a small sealed lead acid. I've no desire to have a big leisure battery on board.

Minimal power requirements on my boat - no electrics at present but there will be LED nav lights and a depth sounder for occasional use. GPS and radio are handheld, and I have little need for anything else so the numbers stack up. I day sail or weekend at most and am moored on a swinging mooring so there's no access to shore power, so something easy to take home is appealing.

 

[davidej]

I use similar packs to fly my electric model planes - but around 2500-3000 mAh - a good bit smaller then these.

Seems excellent value - I have never had a problem with the Chinese ones,. AFAIK they all come from china

 

[Colvic Watson]

That's £2 per AH which is a phenomenal price, lead acid is about £1.20 per useable AH which puts it in perspective - your find is top value

 

[josephmoore]

Thanks guys; probably worth a punt then

 

[DinghyMan]

I think you will find the capacity disclaimer is there for a good reason...

I used to use a lot of chinese lithium ion battery packs in several of the torches I make and have dropped them in favour of good old nickel metal hydride ones; main reason being that the lithium ion were a real lottery and there are loads of fakes and recycled/repackaged one around so I swapped to NiMH as they are much more reliable from a standard and capacity point of view.

Downside is that they are a good bit pricier than the Li-ion you link to, but more reliable. A 5000 mAh NiMH is around the £25 mark, smart chargers from about £11.

 

[septiclecky]

Li-Ion aren't they the one's which Lockheed had a problem with on the 787 Dreamliner that kept catching fire?

 

[TQA]

If you go the lithium route be real careful about charging them. Get it wrong and they can ignite and burn ferociously. They are widely used in the model world and a fair number of modelers have had major fires. http://www.rcuniverse.com/forum/rc-jets-120/11596802-another-lithium-polymer-fire.html

 

[Iliade]

Charge them in a metal container and if they leak, run!

(DAHIK)

 

[josephmoore]

I think you will find the capacity disclaimer is there for a good reason...

I used to use a lot of chinese lithium ion battery packs in several of the torches I make and have dropped them in favour of good old nickel metal hydride ones; main reason being that the lithium ion were a real lottery and there are loads of fakes and recycled/repackaged one around so I swapped to NiMH as they are much more reliable from a standard and capacity point of view.

Downside is that they are a good bit pricier than the Li-ion you link to, but more reliable. A 5000 mAh NiMH is around the £25 mark, smart chargers from about £11.

Good stuff. That's the kind of first hand experience I was looking for surrounding reliability and safety.

As for catching fire when charging, I'm sure they do but given that most smartphones and high end laptops have a Li-Ion battery these days if it was a serious problem we'd be hearing a lot more about it. I can't really speak for the R/C guys as without researching I don't know the type of batteries nor the type of chargers their using. Not all Li-Ion are created equal, and I'm not surprised cutting edge stuff like trying to cram more into less for a new jet airliner has seen some issues. The question is whether these cheapo ones are similar to the reliable ones in our gadgets, or a bit of a liability.

 

[davidej]

I am in the modelling world (aeromodelling not fashion). Yes there have been a very few fires on recharging but only when the battery had suffered physical damage or the charger went wrong.

you can buy pecial fireproof envelopes/bags to put them in when charging

 

[josephmoore]

I am in the modelling world (aeromodelling not fashion). Yes there have been a very few fires on recharging but only when the battery had suffered physical damage or the charger went wrong.

you can buy pecial fireproof envelopes/bags to put them in when charging

Thanks David, good insight

It bugged me a little on the R/C forum thread that no specifics were given about type of battery, use, age, type of charger, common sense of user etc... my experience of supposedly the same battery tech in modern gadgets suggests a degree of reliability. You very occasionally heard some years ago about new release products combusting but those days are gone.

It seems the risk is in the charging of a duff battery, or with the wrong type of charger. I've not heard of any issues in actual use discharging the battery.

 

[viva]

Having experienced a Li-ion battery fire in my camera, which set fire to my luggage I would not dismiss the reports too hastily. The battery was not being charged at the time, so I suspect a short. I was lucky that iit was only my underwear that got burnt! Mine was a cheap Chinese import that I bought to replace the original. I now use only OEM batteries. There was a thread on here some months ago discussing the airline issues with travelling with phones and laptos in hold baggage.

 

[Ed Colonna]

I own a little day sailer and had the same issue regarding power. Have a look at mobility scooter batteries, they are light weight and have a good battery capacity. Worked a dream when I used it and made moving it back and forward from the boat easier than carrying a heavy 12v acid battery. In the end I found a small 12v leisure battery was best and used a £30 quid solar panel to keep it charged. Over the last year I haven't had to take the battery off the boat once as the solar panel keeps it topped up.

 

[josephmoore]

viva - Thanks for that. Decent anecdotal evidence always appreciated. I guess with all things, there's decent Chinese made and then there's dubious Chinese made.

Ed - my initial plan was a 12Ah sealed lead acid, similar to that you'd find on a mobility scooter, with my cheapo 1.5w solar trickle charger. If Li-Ion appears to be a risky dead end, it's probably the route I'll go.

So all things considered with these unbranded eBay batteries, you pays your money you takes your chance. You may not get full capacity, it may burst into flames, it may be brilliant and reliable in every way but just because one is doesn't mean the next one will be the same.

What fun

 

[TQA]

One of the reasons you don't find many reports of mobile phones and cameras going up in smoke when being charged is that they are single cell batteries. You will be looking at a 4 cell pack connected in series. Problems occur as the pack becomes unbalanced. There are sophisticated systems that can charge each cell as a discrete entity.

Now I would be the first to admit that modelers often push their packs to the limit but we have learned the hard way that regardless of how careful you are sometimes these lithium cells catch fire and when they do they are hard to extinguish.

 

[northwind]

Go to a scrap yard and get a car battery, and invest the money in a solar panel. You don't really need a "leisure" battery for the kind of consumption you are going to use it for.

You can then fit and forget it, without the hassle of removing it to charge etc.. unless weight is really a concern?

My battery is always ready to go, it's charged up while we are away during the week, and is no hassle.

D

 

[Berkeley]

I have not posted on here before so apologies if I get it wrong. I have 2 of these to power a Furino fish finder and they have been fine I just run one down and take it home to charge it. I found one battery lasted about 2 weeks with the Furino on quite a bit.

 

[josephmoore]

unless weight is really a concern?

22' boat, heavily built and no racer so I wouldn't say weight was a concern as such but bulk is. If I can get away with something I can pick up with one hand and requires less strapping down in an awkward location then that feels better in mind. Already got a 70Ah battery sitting in the garage doing nothing, plus a 1.5w solar trickle charger that would keep a lead acid topped up. If the fancy options prove too unreliable then I'll spend £20 on a small sealed lead acid and that'll do nicely.

TQA - Interesting thought on the cells being in series hence the increased risk. Makes sense.

 

[viva]

viva - Thanks for that. Decent anecdotal evidence always appreciated. I guess with all things, there's decent Chinese made and then there's dubious Chinese made.

Ed - my initial plan was a 12Ah sealed lead acid, similar to that you'd find on a mobility scooter, with my cheapo 1.5w solar trickle charger. If Li-Ion appears to be a risky dead end, it's probably the route I'll go.

So all things considered with these unbranded eBay batteries, you pays your money you takes your chance. You may not get full capacity, it may burst into flames, it may be brilliant and reliable in every way but just because one is doesn't mean the next one will be the same.

What fun

I wasn't suggesting that products made in China are poor quality. I have a number of Chinese tools/equipment which are very good quality. My comment was meant to indicate that from my experiences with a battery fire I will in future pay a bit more for a battery made by reputable manufacturer who is more likely to have undertaken rigourous tests than buying a cheap alternative

 

[LadyInBed]

I would go for something like this:
http://www.alpha-batteries.co.uk/alarm-batteries/

PS your Red Letter Day photo is upside down