Batteries

Would 2, 24v 3700mAh Ni-Mh packs be ok to run 2, 800w Litton motors with 4QD ncc70 speedos??

Thanks

Will

should do, but if your getting into heavys get a pair of hawkers cant go wrong with them

2 packs is on the low side, I would not reccomend that. We ran 3 x 36V in Hannibal (also Littons 800w).

it all depends on the drivetrain if its a free drivetrain it should be fine , i know turb used to run 6ah with a free drive train, doesnt draw as much out of the batts so they last longer, also depends if your heavy is going to be a pusher you will need more capactiy because you will constantly drawing alot from them, with a flipper you only need to get under them and flip and then move off again

it will work if the cells are good. not got much experiance with those.

Turb used the 3000mah sanyos from battlepack, They did last a fight.. when they were new.. we would of gone for 9amps if we had the weight for it though.

Having said that though- the nicad packs didnt have a very long life in that machine.. probably because we abused them abit..

I would use 3 packs. Never been keen on running 2 packs, other thing to remember is that if a pack goes down, you will pretty much destroy the other pack, at least if you use 3, you can finish the fight on the remianing 2 packs (Merlin has done on several occasions).

We dont plan for a pusher.

We have a pair of big hawkers and some other 17Ah SLAs but these are quite old and we are not sure of their condition.

We need to keep the weight as low as possible.

Would it be better to buy new SLAs (not Hawkers
due to cost) or invest in some Ni-Mh packs?

Also we have seen people charge SLAs with car battery chargers is this acceptable?

We already 2, 14 cell chargers and would have to buy a couple more if we go for Ni-Mh- any suggestions?

Will test the hawkers, if there all good then you mayaswell use them, wont cost you anything and if the machine is overweight when its finished you can swap them out for somthing lighter. We did that with the original turb when it turned out to be 14kg over weight at its first event lol.

Also we have seen people charge SLAs with car battery chargers is this acceptable?

Pick a car battery charger that will charge leisure batteries or SLAs.
Ive been using this model for years.
http://cgi.ebay.co.uk/GUNSON-12-VOLT-AUTOMATIC-BATTERY-CHARGER-model-4106_W0QQitemZ200224558720QQcmdZViewItem?_trksid=p 3286.m20.l1116http://cgi.ebay.co.uk/GUNSON-12-VOLT...el-4106_W0QQit emZ200224558720QQcmdZViewItem?_trksid=p3286.m20.l1 116

(Message edited by woody on July 06, 2008)

I have a question, I have just switched over from 24v 3600mah Nicds to 2 Hawker/Odyssey PC535 24v 13AH batteries, due to cost $96 US instead of $172. But at the expense of weight, my question is do any of you guys running these batteries charge between fights or is there enough juice to run say two fights ? The Defyer is HW two wheel running on two mags.

Martin

Martin, you should always aim to charge hawkers between each battle. The deeper they are discharged, the shorter they live.

Thanks that what I thought but just wanted to check

Would this be a suitable charger just to check these old SLAs Will and I have aquired !
http://www.argos.co.uk/static/Product/partNumber/7402137/c_1/2%7Ccategory_root%7CGarden%2C+DIY+and+leisure%7C95 54618/c_2/3%7Ccat_9554618%7CCar+equipment%7C9554675/c_3/4%7Ccat_9554675%7CCar+battery+chargers%7C9554688.h tm?Price+Cut=1http://www.argos.co.uk/static/Produc...ategory_root%7 CGarden%2C+DIY+and+leisure%7C9554618/c_2/3%7Ccat_9554618%7CCar+equipment%7C95546 75/c_3/4%7Ccat_9554675%7CCar+battery+chargers%7C9554688.h tm?Price+Cut=1

Ian, That would do very well.

Thanks Leo...as the spec says Suitable for use with car batteries - 6 volts/12 volts/ sealed/ lead acid/ gel cell batteries between 20-120Ah - Charging rates 5.3 amps RMS would it be advisable to charge 17ah in parallel ? Read somewhere optimum C is 25% of capacity for SLAs

Our current batteries are old but we might buy some new SLAs so want to make sure we use the chargers properly from the start. At £20 each cant be a bad buy if there upto the job !

I would only charge batts in parallel when they are new so they act as 1 battery. Old ones you might get more of a charge in one than in the other due to memory effects.

I wouldnt worry too much over the minimum Ah rating of the charger, its a pretty intelligent charger and it will slow down in time.

If they are Hawkers, then you really need to read the application manual:
http://www.commutercars.com/downloads/batteryCharging/HawkerGuide.pdfhttp://www.commutercars.com/download...awkerGuide.pdf

Hawkers are different from other lead-acid batteries. A lot of people do not realise their potential (and shorten their life) by not charging them correctly. In particular, you must charge them at 14.7 to 15V, no less.

I would NOT recommend using any lead-acid battery charger that does not specifically say it is designed for Hawker batteries.

Also, as it says in the manual - there are no restrictions on the current limit. One good way to charge them is just to use a big 12V power supply, like the 40A one that a lot of teams use -http://technobots.co.uk/acatalog/Online_Catalogue_Power_Supplies_29.htmlhttp://technobots.co.uk/acatalog/Onl...pplies_29.html -
set to 14.7 Volts and connect the battery/batteries directly to it and let them draw as much current as they want.

We use to charge ours with a power supply, and took them off when the current dropped to about 1amp.

Im NO expert on charging batteries but the charger I previously linked to on ebay ... new link provided here http://a1autowise.com/BatteryCharger.aspxhttp://a1autowise.com/BatteryCharger.aspx

Seems to meets the requirements stipulated by http://www.odysseybatteries.com/charging.htmhttp://www.odysseybatteries.com/charging.htm

(Message edited by woody on July 12, 2008)

Thanks all for your help. We tried the cheap option from argos and either the cells are duff or they are not upto the job...so they are going back ! One last question....the power supply linked from technobots....is this a variable current adjustable / limited one...do we need one (? / advisable) or just set the votage and go ! We aslo found another alternative...
http://stores.ebay.co.uk/TK-RADIO_POWER-SUPPLIES_W0QQcolZ2QQdirZQ2d1QQfsubZ9476935QQftidZ2 QQtZkmhttp://stores.ebay.co.uk/TK-RADIO_PO...d1QQfsubZ94769 35QQftidZ2QQtZkm
These prices for the lower amp ones look quite reasonable. Still undecided to but new SLAs or go NiMH ! If we go SLAs would even the cheaper non hawker SLAs be perfectly ok to charge like this ? (well need a couple of sets and £400+ is a lot of pocket money and bedroom tidying for Will !!)

i dont know if they still on ebay but i got 12 brand new packs of 4000mah ni-mhs off ebay for 130 quid, i have soldered them into packs of 28.8v 4000mah giving me 12ah of ni-mh.

A number good charger is also at:http://www.ctek.com/EN-GB/Default.aspxhttp://www.ctek.com/EN-GB/Default.aspx