Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Batteries & Chargers => Topic started by: cos918 on June 16, 2014, 08:26:59 pm

Title: Lipo question.
Post by: cos918 on June 16, 2014, 08:26:59 pm: Hello all
I am looking at get a lipo for my ferry boat . I am lookig at a Turnigy 7.4v 6ah 25c battery.
http://www.ebay.co.uk/itm/RC-Turnigy-nano-tech-6000mah-2S-25-50C-Lipo-Pack-/131209080666?pt=UK_ToysGames_RadioControlled_JN&hash=item1e8cabaf5a

I have 2 questions
1. The motors on the boat pull 3ah max between them does this mean I have 2hr running or would that damge the lipo buy making the voltage on the cells to low
2. after say 100 cycles will the battery still hlod 6ah.
many thanks
john
Title: Re: Lipo question.
Post by: malcolmfrary on June 16, 2014, 10:47:06 pm: If the motors between them pull 3 Amps, yes, that will give about 2 hours from a 6AH battery.
Batteries do age, depending on their initial quality and the way they are used and/or abused, so there is no way of foretelling how well any particular battery will perform many cycles down the line. But they should be OK after 100 cycles provided nothing untoward happens before then.
Title: Re: Lipo question.
Post by: cos918 on June 17, 2014, 04:33:17 pm: Hello Malcomfrary
Thank you for clarifing That

john
Title: Re: Lipo question.
Post by: Time Bandit on June 17, 2014, 06:42:19 pm: You have to keep in mind, that LIPO loose a few % of their capacity per year.
Even if you treat them very well, they lost a few % after winter.
They also use capacity over their number of cycles. If we calculate 300 cycles max using, after 100 cycles they should have between 60 and 70% left.

If you want more steady batteries try to get LiFePo4 batteries. I use my big Headway cells since 4 years with around 60 cycles and they still have nearly 90% of their initial capacity left.

If you want to stay with the Lipo, get it from Hobbyking directly. Should be much cheaper.
Title: Re: Lipo question.
Post by: cos918 on June 17, 2014, 08:38:52 pm: thankyou

john
Title: Re: Lipo question.
Post by: kmmbcwebmaster on June 17, 2014, 09:49:05 pm: Word of advice if ordering lipo battery's from overseas the law on the carriage of lipo batteries has changed they can no longer travel via air freight because of the danger of explosion so they can only travel by land or sea .
at present hobby king have a charge of £8 for shipping from global site but if you order from uk warehouse your only charged standard p&p
Title: Re: Lipo question.
Post by: cos918 on June 17, 2014, 10:16:11 pm: Just got them from the HK Uk warehouse. they were cheeper than ebay. There postage was a bit steep at £11 for X2 lipo.

john
Title: Re: Lipo question.
Post by: nick_75au on June 21, 2014, 05:05:09 am: Quote from: kmmbcwebmaster on June 17, 2014, 09:49:05 pm
Word of advice if ordering lipo battery's from overseas the law on the carriage of lipo batteries has changed they can no longer travel via air freight because of the danger of explosion so they can only travel by land or sea .
at present hobby king have a charge of £8 for shipping from global site but if you order from uk warehouse your only charged standard p&p

This is simply not true, there are restrictions but they can be air transported still, main restriction is travel as cargo on passenger planes has been discontinued and only for lithium metal ( Lipo is Lithium ion) batteries. You can also carry the batteries for personal use again somewhat restricted to capacity and how transported BUT THEY can be transported by air.

http://www.dhl.com.au/content/dam/downloads/g0/express/shipping/lithium_batteries/lithium_ion_batteries_regulations.pdf (http://www.dhl.com.au/content/dam/downloads/g0/express/shipping/lithium_batteries/lithium_ion_batteries_regulations.pdf)