LiPo

[plargen]

can you use normal chargers from NiHm on LiPo battery's or do you need a special charger

[Anttazz]

Re: LiPo

Some can do both, but are primarily LiPo. What charger do you have?

[plargen]

Re: LiPo

just the bog standard rc 1s

[Anttazz]

Re: LiPo

Wouldn't really say there is such a thing, most LiPo chargers I've seen though advertise it with lots of large writing on them so I would assume yours is not one of them. They would also have a balance connection.

[plargen]

Re: LiPo

probably easier and cheaper to stick with NiMH battery's and chargers then

[typhoon_driver]

Re: LiPo

for lithium polymer, no you can't however there is a way for the lithium A123 cells using a dapter. A bit of kit that sits in between the charger and cells and cuts off at the right voltage.

[PJ-27]

Re: LiPo

Most modern day chargers that can do enough Nimh / Nicad cells can do Li-Po and have a built in balancer.

I got an iMaxB6 for £8 On ebay. Here's one for 99p..... Whether you trust it is at your own discretion.

http://www.ebay.co.uk/itm/IMax-B6-Digit ... 3f1033d919

[plargen]

Re: LiPo

ok will look into it a bit more thanks

[roketrhino900]

Re: LiPo

I know this is mostly resolved, but the build rules state chargers must be built for the same chemistry of battery. So you can't use NiCad on LiPo, for example.

[razerdave]

Re: LiPo

I have been reading the rules with regards to LiPo batteries and there is one thing that I have been told a few times but doesn't appear to be in the rulebook; Metal boxes for lipos.

I have been told that Lipos have to be charged in a metal box and/or a Lipo sack, and should also be in a metal box inside the robot, or have at least a 2mm thick metal base underneath to protect the floor if the lipos go up.

Can someone clarify this ?

[Mouldy]

Re: LiPo

Thats right Dave...

the metal box for charging is redundant, those rules were drafted up before lipo sacks were easy to get hold of... get a lipo sack. There cheap enough on Ebay these days.

At tech check for people using lipos i check for the following;

2mm+ METAL base plate under the lipo + security of the lipo (I.E. It isnt cable tied to the pneumatic cylinder *cough* Mr Lear *cough*)
Secure well insulated connections within the robot + the connectors being used are sufficient to cope with the maximum current draw.
Sufficiently rated fuse on the positive side of the lipo, thats rated below the maximum discharge of the lipo.
The visual state of there lipo
The charger + balancer combo the competitor is using is suitable
The competence of the person using the equipment.

Im a bit more strict then some tech checkers when it comes to lipo's, but most of the people using them so far have enough common sense to think of all that them self.

[chompalot]

Re: LiPo

I see that the type of metal hasn't been specified, is aluminium OK for the under LiPo plate?

[maddox10]

Re: LiPo

7.8 LiPo
Lithium Polymer batteries have specific limitations and extra precautions which must be adhered to.
7.8.1 Balancers
Appropriate balancers must be provided if not part of the charger. They will be inspected during the
Technical Check. LiPo batteries should be properly balanced to prevent damage occurring to the cells.
7.8.2 Voltage Cut-out (Advisory)
The robot should be fitted with an under voltage cut-out or alarm set at or higher than the battery
manufacturer€Ÿs recommendation to prevent the batteries from becoming damaged by over discharge.
7.8.3 Fusing
A fuse rated below the maximum burst discharge of the battery must be fitted.
7.8.4 Extra Equipment
Roboteers using LiPo batteries must provide a LiPo sack.
7.8.5 Inspection
LiPo batteries must be removed from the robot, inspected and placed into a LiPo sack prior to and during
the charging process.
7.8.6 Charging
Lithium batteries must not be left unattended at any time during the charging process. Leaving batteries
unattended while charging will be considered a serious breach of pit safety and may result in you and
your robot being removed from the event.
7.8.7 Damage
LiPo batteries showing any evidence of damage or swelling must immediately be placed a LiPo sack and
removed to a safe, well-ventilated area such as outdoors.

Don't see any remarks on metal battery-baseplates.

[Danjr1]

Re: LiPo

How set in stone is the metal plate rule?

[razerdave]

Re: LiPo

Well according to the rules it's not there at all. However with Mr Moulds experience with lipo's, the metal plate and/or box is well advised.