ko esprit II vantage replacement batteries

[Big G]

I replaced the batteries in my tranny with some £8 from HK GP 3000mah nimhs a few months ago. since my tranny is the older of the several vantages it doesn't have the tabs to just pop AA's in so I soldered them together into 4's (obviously).

I only seem to get 2 nights racing out of a charge then they go flat really quickly. When charged they read 11.0v, but once the alarm goes off at 9.0v they drop voltage very quickly.

Any suggestions for good batteries to replace mine or indeed proper packs?

maybe 2x 3cell 11.1v heli packs would be better wired in parallel...?

ty

[IceMike]

ask neil oliver if he can sort u out mate, i had some off him sometime last year, and they can go for forever without me charging them up.

[Big G]

what about these?

http://cgi.ebay.co.uk/2x-11-1v-900ma...ht_2873wt_1087

I can find 2mm in height to squeeze them in. would need to hook them up in parallel to give a total 11.1v and 1800mah and then just charge then individually through the balance port...

does anyone know if I can charge through the port with the charger set to 3 cell lipo at 1A? wired in parallel aren't they same voltage double capacity?

[Hog]

In the same boat as you Big G. My KO packs are getting tired (think they're only 1100mAh anyway). Managed to find some 2700mAh AA cells on fleabay and I'm just waiting for them to come from HK now.

Only trouble I'm having is finding AA sized solder tags. Any ideas?

[Big G]

well I used just tiny bits of wire. like an inch and soldered them on. maybe I cooked the batteries doing it?

I'm gonna try those lipos I recon. Gaining 2mm won't be hard on the height. remove the plastic and support them with gaffer tap lol. the little gap down the side will be enough to keep the balance plugs. There's easily enough room behind to gain that much.

I was thinking about moving the module to the side, but this is a better way I recon.

I'll post a step by step when I do it.

[Hog]

Possibly cooked them. They do recommend "spot welding" instead of soldering to cells, but we've all been soldering to Sub C NiMh's for years without problem - perhaps it's just the small size of the AA cell which doesn't help.

I've found some 15mm long tags so i'll give those a go.

Just wich the damn cells would arrive from HK!!!

[Big G]

I ordered a motor from toyeast on ebay on the 4th and it arrived on yesterday. so 15 days delivery. Suppose I should just be happy given their 15 or so negs for the last 30 days lol.

My AA's from HK were pretty quick when I got those.

I think the 1st charge through the port I'll remove them from the tranny and put them in the lipo bag with the extinguisher to hand. just in case...

[Big G]

if my tranny has 3000mah nimh AA's in it now shouldn't it take 3000mah from flat from my charger?

it seems to take like 250mah before saying it's charged. I use my normal battery charger setup to 8 cells and 0.8A. there are some nimh peak sens settings or something I haven't really fiddled with...

should I just keep putting it on until the batteries get warm like nimhs do when they're charged?

[Battle_axe]

Originally Posted by Big G

if my tranny has 3000mah nimh AA's in it now shouldn't it take 3000mah from flat from my charger?

it seems to take like 250mah before saying it's charged. I use my normal battery charger setup to 8 cells and 0.8A. there are some nimh peak sens settings or something I haven't really fiddled with...

should I just keep putting it on until the batteries get warm like nimhs do when they're charged?

i charge mine at 1A and the cutoff set at 20mv seems to work fine with my ansmann 2400mah cells

[Big G]

I changed the cut to 15mv which is the highest I can do on my charger and they took a fair bit more. got them to warm up now so I guess they're charged. I'll find out how many nights racing I get now then.

[Big G]

woot. now got a 3 cell lipo powering my tranny. Time to test now long it lasts on 900mah of juice

I would of installed 2, but the space was a bit tight since the supplier made an error in their ad so they arrived 18mm longer than I expected