Batteries

[leorcc]

Batteries

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.

[terrorhurtz]

Batteries

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.

[blazerbotics]

Batteries

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

[woody]

Batteries

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, 200

[Ianshock]

Batteries

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 !!)

[Kenny]

Batteries

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.

[mattan]

Batteries

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