Batteries

Hi guys.
Best batteries for a featherweight? I know my options (Gel-Cel, Nicad, NiMH ect) but which are best, good value for money, easiest to deal with ect.
Also Ive never been very good with voltages and currents so can someone give me an idea of the best running voltage and that for a good reliable featherweight. Links would be good too.
Cheers. Dave

Dave youve posted one of those how long is a piece of string questions.

Nimhs seem a favourite choice .....voltage and Amp/hrs depend on your motors and gearing.

I did want to know how long a piece of string is...lol.
Its running on drill motors.

a piece of string is twice the length from the middle.

(Message edited by ady on November 08, 2007)

2 drill motors?
4 drill motors?
what voltage are the drill motors?
Will you use a weapon that uses electricity?

All these things we need to know to give the best recommendation.

2 drill motors, not sure on the voltage but Im getting them off James Cooper so Im guessing the standard ones. If I do go with a weapon (havent decided yet) itll be on a separate circuit with a separate battery, so Im just on about for the drive for now.
Its going to be much more of a fun bot than a highly serious competitor for now, Im not building a wedge that has to push all day long. Im just looking for it to have fairly decent speed and power (I know this depends on the wheels as well before someone points that out), be able to last the full battle, and be an easy recharge between.
Also the piece of string advice was very helpful too. lol.
Cheers.

I consider the norm for drill motor voltages to be between 9.6v - 36v.... there isnt a standard voltage.

I think theres a formula to guesstimate the number of knots you can get in the string if all the unknown values add up to 89.

If I was to start a feather like that:

For drive, 2 drillmotors of 9,6V to 12V, I would put 2 NiMh racing packs of 7,2V around the 2000mAh to 2400mAh mark in series so you would get 14.4V. It is easier to find good inexpensive chargers for 7.2V racing packs than it is for 1 14.4V pack.

Add these to a Scorpion (X)XL or a Sabretooth controller, and attach those very nice blue wheels that James Cooper sells and your ready to go.

Thanks Leo, yes thats pretty much what I plan to do. :)

Hi, Its question time... Again
Where do you guys get your battery packs made? Id be looking for somthing in this sort of layout with all the cells stood up like those battle packs. like these.
http://www.component-shop.co.uk/assets/images/150_8vp3700sc-w.jpghttp://www.component-shop.co.uk/asse...vp3700sc-w.jpg

i need somthing roughly 12v 4300mah and either 14.4v 4300mah+ or 18v 4300mah+
Cheers Fellas

just buy thme off ebay search for vapextech they do some good deals, if they dont have what you want just ask and they might be able to make it for you

btw what sort of batteries do you mean? nicad nimh...etc

Nimh. ill keep looking

http://www.modelpower.co.ukwww.modelpower.co.uk

Actually, I think Vapextech are superb too. Quite cheap and delivery is never more than a few days.

Andy

Vapextech is up and coming in dutch modelling like boats and cars, and most results are very positive given their price/performance.

(Message edited by leorcc on September 30, 2008)

Here is their ebay shop

http://stores.ebay.co.uk/Vapextech-Batteries-and-Chargers_W0QQssPageNameZstrkQ3amefsxQ3amesstQQtZkmhttp://stores.ebay.co.uk/Vapextech-B...geNameZstrkQ3a mefsxQ3amesstQQtZkm

Andy

i have ordered from them befor i have a few 12v 3700mah batts and some 7.2v batts from them but they havent got back to me about making me some custom packs.

I can telly you about that. They can supply the cells. They can supply the heat shrink sleeving. They will not make them up for you.

(Says the man with 80 individual cells ready to be made up to 24V packs ready for Saturday with SMIDSY - anyone want to offer odds on SMIDSY appearing at Portsmouth?)

Andy

I ordered some from them before but they couldnt provide the current I needed. Might just be my bad experience with them but I was only using a couple of golds and a wiper motor.

Worst 60 quid I ever spent.

I get mine from various sources but the best has been overlander. Doubt they do custom jobs though.

How about http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&it em=360094704026http://cgi.ebay.co.uk/ws/eBayISAPI.d...WAX:IT&item=36 0094704026
If i was to use 2 at a time to get 14.4v would i have to charge them individually or can they be paired and charged? Cheers

I believe that this is better
http://cgi.ebay.co.uk/Two-7-2V-4500mAh-NiMH-Battery-Packs-For-RC-Cars-Tamiya_W0QQitemZ260291820046QQihZ016QQcategoryZ340 61QQtcZphotoQQcmdZViewItemhttp://cgi.ebay.co.uk/Two-7-2V-4500m...ars-Tamiya_W0Q QitemZ260291820046QQihZ016QQcategoryZ34061QQtcZpho toQQcmdZViewItem
You get 2 for about the same price as the one you linked.

are they a better battery or just better cos there cheaper?

I dont know about the performance between these two, but Id rather get 2 packs for the the same price.

(Message edited by flippt on October 06, 2008)

imm gunna go slightly of topic here but with the spektrum tx/rx charger (the 2 pin one) what adapter do i need for the uk plug sockets? i have found a voltage dropper one http://cgi.ebay.co.uk/UK-US-USA-Adaptor-Converter-Transformer-Plug-45W-45VA_W0QQitemZ130259491314QQihZ003QQcategoryZ96942 QQssPageNameZWDVWQQrdZ1QQcmdZViewItemhttp://cgi.ebay.co.uk/UK-US-USA-Adap...-45W-45VA_W0QQ itemZ130259491314QQihZ003QQcategoryZ96942QQssPageN ameZWDVWQQrdZ1QQcmdZViewItem
Would this be ok?

If you have a futaba charger you could always just open up the spectrum and swap the positive and negative around on the charge jack.

right. what about charging my 7.2v batts then? im using 2 of them in the robot to make 14.4v but would you charge them as there paired up as 14.4v or charge them seperately?

Yes if in series like you say you add the voltages together, but leave the capacity (Ah) the same as a single cell.

so instead of charging at 7.2v 6 cells on my constellationi put 14.4v and keep it set at 6 cells? will they both charge evenly?

Im not 100% sure on this as I dont use a constellation charger but if you are charging two packs in series it will be equivalent to 12 cells (14.4V) so my guess is you would need to set it to 12 cells rather than 6; hopefully someone can confirm this though

well just spent £121.85 on batteries at component-shop.co.uk. Man this is an expensive hobby. Worth it tho.

how many have you bought and what sort that sounds mega money for 2x 7.2v packs!!!!

i got 4 7.2v packs and a 12v pack and a some other rechargeable batts.

Hello fellow roboteers. Its kinda frustrating having to take Anxious appart every time i need to charge the batteries. it has 2 X 7.2V batts inside giving me 14.4v. could i put a little window in the top or bottom of the robot for a charging point? So i dont have to disconnect the batteries and so i can charge them together while there still pluged into the bot. If i can how should i do it? i dont wanna damage anything.
Cheers

Hey Tom,
Came across this picture somewhere a couple of years back:

http://i31.photobucket.com/albums/c367/ayrshirerobotics/Random/charging.gifhttp://i31.photobucket.com/albums/c3...m/charging.gif

Just take a couple of connections off the main battery wires and fit a charging plug as shown. Then you can just add a little window or hinge door to access it

Hope thats of help

cheers. will save me alot of trouble at events doing it like this.

Really good idea to have a charging port, you can just unplug and go 30 secs b4 a fight without having to have a couple of minutes to put armour back on.

more than a couple of mins with anxious. cos its so compact and a strange shape motormounts and baseplate bolts need undoing. 20+ screws to take out and put back in. stupid robot... or stupid designer? yeah its my fault for making it that way.

- id advise you make sure you take the link out while charging though!

:lol:

Job done. well in 1 of the robots. now for the other 2 that need it doing. just hope they charge ok charging the 7.2v batts paired up. ill de-charge them and fully charge them seperately first hopefully they will have equal charge then.
Cheers.