Hinckley Radio Control Car Club

OK mate, no probs.

If you hear of anyone after any cheap batteries then let me know please? (I am going to try to match them into 4 cell packs sometime this week)

Anyway, I charge my Intellect 4200's at 6 amps.....I dont know what the recommended charge rate is but I have had no problems charging at this rate.! (I even charge my new 08 spec batteries at 6 amps). It may be worth checking the manufacturers recommendations though.

If I was to charge at 4.2 amps they would take an eternity to charge.....also, I find that a higher charge rate gives the cells more power/punch at the expense of a little duration/runtime although this is obviously not an issue with a mardave.

Common sense would suggest that the higher the charge rate, the lower the life span.....???? So I guess it comes down to personal choice.

A word of advice though......If you go for the 4200's which I have found to be very good batteries, it is a good idea to make sure they are properly discharged after use, and equalised if possible. This will ensure they maintain maximum performance, and increase the lifespan. Also, if you are not going to use them for a period of more than a week....they should be left part charged (about 1000Mah)....and re-discharged/charged to 1000Mah on a weekly basis.
The majority of people running these cells have found that they lose charge when left and if they are left in a discharged state for too long the cells may get as low as 0 volts and will not take a charge.

Hope this is useful
Daz

Daz. . . .
from new do you still need to trickle over night then 6amp after that

Any way going down to the http://www.midlandercc.co.uk/index.html to night ( thursday) to play is there any where else local that run mardave's. . . .

To be honest, I have never trickled my batteries......or not for about 15 years anyway.

I think it depends on what you buy.....If you buy 'matched' then they will have already been charged/discharged a number of times to allow them to be matched. Therefore they should be ok to just go straight into charging.

The only other clubs I know of are Leamington on Wednesdays and Beaumont Leys on Fridays.

I would advise that you charge at 1C, as per the brca charging guidelines. This means 3.3A for 3300mah cells, and 4.2A for 4200mah cells.

In my opinion, If at all possible, I would avoid intellect IB4200's. They are one of the most unstable types around, that self discharge badly when stored. Also, throughout the past few years, there have been many cases of these exploding, hence the reason for the brca issuing guidelines for charging and cell handling. However, if you get a decent pack, they will perform very well indeed. Hence why they are very popular.

Looking at the 1/10th Off-Road and 1/12th circuit racing from this year, the popular cell has been the Ener-G 4600. However, these are fairly expensive, and quite difficult to get hold of. Popular cells for mardave's, include E-Power 4500's, Yuntong 4300's, Vapextech 4300, and BATT 4000's. From what I've been told, the 4300's are the more stable / solid cells. Yuntong's and E-Power's are available from Demon (no stock at the moment though), Vapextech are available from TJ Cells, and BATT 4000's are from BRM.

As Daz has said, if you buy matched cells, they would have been cycled a few times during the matching process, so trickle charging wouldn't be necessary. It may be worth cycling them yourself when you first get them though. Charge at 1C to max capacity, select a low delta peak cutoff, then discharge the pack to around 4.4V or so, and then equalise to 0.9V per cell.

hope this helps.

Hi,

I have been running IB4200's for about 2 years now and have not had a single problem with them exploding and I charge them at 6 amps.....sometimes more if I am struggling for time. I will agree however that the self discharging is a right pain in the ___.! I think the key is to use a good quality charger and remember to discharge and equalise them after every run, and then part charge before storing them.

To be perfectly honest though, I have found exactly the same thing with all Nimh cells. I am now running '08 spec' EP4600's in my touring car and these tend to self discharge in the same way as the IB4200's.

Now to confuse all of you......My understanding is that the Ener-G 4600's are actually Intellect '08 spec' 4600's re-shrink-wrapped. In the same way that the LRP/Nosram Big Mamas and Fat Cobras are also re-wrapped Intellect/East Powers respectively.

I cant comment on the other makes (Yuntong, BATT 4000...etc) as I haven't really heard of them or had any experience of them.

A word of advice though.....If you are looking for cheap new batteries, it may be worth looking at Precision-rc, or rc-mushroom in hong kong as they do the '08 spec' cells at about 1/2 - 2/3 the price they are here......and my last 2 orders from precision-rc have arrived inside 4 days.

Thanks
Daz

A bit late but aww well
cheep cells hey Demon power products or kamtec