Charging in the field

[Aire valley]

Originally Posted by RandomConflict

After my leisure battery packed up late last summer, I went for one of these:


http://www.hardwarexpress.co.uk/evx1...20ah-448-p.asp


Will do a full days charging and more, can charge around 9 or 10 2S LiPo race packs without any problems. When I get home, I just stick it on charge with my Orion Adantage Touch and charge it back up. I've also run soldering irons on it, all through the winter in some of the coldest conditions I've raced in. Plenty of power for a full days racing, and probably enough to get through the next day aswell!


So much lighter, cleaner and smaller than any other option! And Corally type connectors fit perfectly into the screw holes in the top!

20ah seems rather small.....? Most people seem to use 75ah or 100ah..
I like the idea , and price, but is it up to the job ..?

[V6Jim]

Originally Posted by Aire valley

20ah seems rather small.....? Most people seem to use 75ah or 100ah..
I like the idea , and price, but is it up to the job ..?

I thought that myself.

20Ah means (I think) that the battery will supply, at best, 20 Amps for a period of one hour.

By my reckoning that should be able to charge 4 x 5000mAh packs from flat. That might be enough to get through a days racing....

Jimmy

[RandomConflict]

Originally Posted by V6Jim

I thought that myself.

20Ah means (I think) that the battery will supply, at best, 20 Amps for a period of one hour.

By my reckoning that should be able to charge 4 x 5000mAh packs from flat. That might be enough to get through a days racing....

Jimmy

I tried to do the math before taking the plunge, I thought I'd get 5/6 race packs out of it, putting around 1600/1700mah back in after each race before the Lead Acid battery went flat.

I have charged 8 packs in the past, putting in on average 1700/1800mah back in after each run, and when charging the Lead Acid battery that evening, my charger put around 10,000mah back in. It's all to do with discharge rates etc. aswell. I charge my race packs at 6 amps and the Lead Acid battery more than copes. It probably wouldn't last you a whole weekend, but is more than capable of lasting for a whole days racing, 5 races and 2/3 practices.

[kaszal]

Originally Posted by RandomConflict

I tried to do the math before taking the plunge, I thought I'd get 5/6 race packs out of it, putting around 1600/1700mah back in after each race before the Lead Acid battery went flat.

I have charged 8 packs in the past, putting in on average 1700/1800mah back in after each run, and when charging the Lead Acid battery that evening, my charger put around 10,000mah back in. It's all to do with discharge rates etc. aswell. I charge my race packs at 6 amps and the Lead Acid battery more than copes. It probably wouldn't last you a whole weekend, but is more than capable of lasting for a whole days racing, 5 races and 2/3 practices.

I too decided to get one of those CSB 20Ah leisure batteries...

http://www.ebay.co.uk/itm/2906804336...601%26_rdc%3D1

I've got an Turnigy Accucel 6 charger and 15v power supply. What settings do you use to charge yours? Do I just set the charger to "pb" mode (12v) and set the current? The CSB specification (link below) says 6A max charging current so I figured half that should be safe to start with?

http://www.csb-battery.com/english/0...p?fid=4&pid=47

[PurcyP]

You say you cant charge a car battery with a normal charger?

I have a Core UAC50 and it supports 12v pb, if you follow the bench charge rate the battery states, for example mine is 4 amps then its no issues, just set a mAh cut off as it can struggle to read the peak sometimes.

ive charged my spare car battery with it and then used it to charge my lipos without many issues, although i would like to invest in a leisure battery with handles as lugging this car battery around is anything but easy.

[Danny Harrison]

Originally Posted by PurcyP

You say you cant charge a car battery with a normal charger?

I have a Core UAC50 and it supports 12v pb, if you follow the bench charge rate the battery states, for example mine is 4 amps then its no issues, just set a mAh cut off as it can struggle to read the peak sometimes.

ive charged my spare car battery with it and then used it to charge my lipos without many issues, although i would like to invest in a leisure battery with handles as lugging this car battery around is anything but easy.

I allways thought 12v pb was like the golf trolley batteries. Sealed lead acid type and similar. Pretty sure a car battery is on same lines as a leisure battery and wont like pb setting too much. Im sure it will charge, but I would't do it personally.

[PurcyP]

Pb is the name on the periodic table for lead

all sealed lead acid batteries are pb by chemistry, be it leisure, those little golf trolley ones or even car batteries, all use the same chemistry

if its a 12v lead acid car battery aka leisure battery and has a bench charge rate of 4 amps then there i guess there is no reason why any charger that supports pb chemistry cant do it?

[Danny Harrison]

Originally Posted by PurcyP

Pb is the name on the periodic table for lead

all sealed lead acid batteries are pb by chemistry, be it leisure, those little golf trolley ones or even car batteries, all use the same chemistry

if its a 12v lead acid car battery aka leisure battery and has a bench charge rate of 4 amps then there i guess there is no reason why any charger that supports pb chemistry cant do it?

Fair one, I was in same boat myself last month, but all the answers I got were that you shouldn't do it. Seems logical though

[HOTSHOT III]

Originally Posted by PurcyP

Pb is the name on the periodic table for lead

all sealed lead acid batteries are pb by chemistry, be it leisure, those little golf trolley ones or even car batteries, all use the same chemistry

if its a 12v lead acid car battery aka leisure battery and has a bench charge rate of 4 amps then there i guess there is no reason why any charger that supports pb chemistry cant do it?

Purcy...it's green.

Joking apart you're right, Pb = Lead = lead acid battery in this context

[PurcyP]

Paha that joke is going to stay around for a while i think

[kaszal]

http://www.youtube.com/watch?v=TkZFuKHXa7w

[dodgydiy]

12v 20ah is 240 watt hour, a 5ah 7.4v lipo is 37 watt hour providing my maths is correct. the 20ah battery should be good for 15-17 AH useable capacity or around 200 watt hours so should be able to fully charge 5 5AH packs from flat or ten from half charged, plenty for the average days racing with one car. have a look around for a 40ah gel cell from an electric wheelchair, another cheap power source, a lot of companies fit new ones when servicing a chair even if there is nothing wrong with the old ones