Battery trouble - again!

[jdbostrom]

Hi,
I have a Laser 4 channel surface radio and I am having some trouble with the Tx battery. When I got the radio, I was careful to charge the battery a full 24hrs like the owner's manual said to do. I used the radio every now and then and it worked fine. However just recently I got the radio out and charged it for about 12-14hrs. When I turned the radio on it showed on the LED battery indicator that the battery only had 60% power. I figured that the battery just needed to be put through the charge/discharge cycle a few times like I had been told to when this sort of thing happened. So I cycled it a few times and still, only 60% power. Any recommendations?

Thank you,
Jonathan


I sent this email (above) to the Hitec service dep. and was told that my problem was a bad cell, and I should talk to someone at Cermark Electronics (800-704-6229). However I really don't understand this because I've only had the radio for about a year and I have not used it very much at all.

Secondly, if I MUST buy a new battery, I would like to buy one with a higher capacity than the last one (More running time). Do they make NiMh Tx packs?

Jonathan

[wingtip]

YES they make nikel metal

YES they make nikel metal packs..but my question is what is the charge rate on your charger that you charged it at 24 hours????? i'd say you fried it by over charging it... most basic tx packs are around 600mah and a charger rating of around 50mah which would take 12 hrs if fully depleted... a 100mah charger would take 6hrs etc etc etc... to safely charge 24hrs with the 600mah pack as an example your charge rate couldnt be more than 25mah....
i'd say its toast...just get a bigger capacity one but you'll need to then get a special charger if u go nimh unless you calculate as above on exactly how long it will be on charge and remove it when neccesary.........

[jdbostrom]

Ok, thank you. http://www.subcommittee.com/forum/icon_sad.gif

The

Ok, thank you.

The instructions said to charge it initially 24hrs though.

Since I am almost completely ignorant when it comes to batteries, can anyone help me decide what charger I want if I was to go NiMh? And is it really worth going NiMh in the first place?

Jonathan

[wingtip]

if you plan on having

if you plan on having multiple vehicles to run throughout the day or just multiple rx packs for a single vehicle you may want a nice nimh tx pack... you could stick with a nicad and a spare... its always good idea to have a spare anyways......
just depends if you feel like charging in the field as needed or just want one that will last all day ... check duralites out...

[petn7]

i like using nicads in

i like using nicads in my TX because it can hold a charge for months. i usually work on my projects in spurts throughout the year (school and all) so it's nice to be able to use my tx after it's been sitting idle for 4 months. also, when you charged for 24 hours, you charged at low rate, right?

[jdbostrom]

Petn7,
That is exactly how

Petn7,
That is exactly how I work on my projects; my transmitter sits there for months unused and then I use it every day for a period of a week or so when I am at the lake.

I guess it would be the low rate, I just plugged the charger that came with the system into the transmitter and charged it for 24hrs, like it said.

By now I have decided I would like a high capacity NiCd pack. Where would be the best place to buy from, Tower Hobbies?

Jonathan

[petn7]

Tower Hobbies would be a

Tower Hobbies would be a good place to buy the factory stock batteries that originally came with your tx; not sure about hi-cap nicads. when you charged for 24 hours, it was a trickle, charge right? like 1/10 C? like my tx uses a 800 mah nicad, so ideally i would trickle charge around 80mah for 24 hours

[petn7]

http://www.towerhobbies.com/listings/cat-cat-l.html

but i don't think they

http://www.towerhobbies.com/listings/cat-cat-l.html

but i don't think they have what you're looking for

oh, and my tx battery is 600mah capacity, not 800 (not that it matters, but i thought i should correct myself )

[jdbostrom]

Like I said, I really

Like I said, I really don't know. I just plugged in the charger and did what the instructions said to do. The charger is just a simple wall charger that has no buttons, switches or any thing else on it. It just says]http://www.subcommittee.com/forum/icon_biggrin.gif[/img]

[petn7]

yeah, it doesn't sound like

yeah, it doesn't sound like you overcharged your cells. i use a MRC 959 charger to charge my Sub C cells, AA and AAA sized battery packs no problem (peak charged too) even if they are nicad or nimh. for my tx, i just use a standard charger where i can choose different charge rates. when the tx battery is low, i just pop out the battery and charge it around 200 mah or so for a few hours. i don't worry about cycling or stuff since i probably end up charging the battery twice a year at the most.

here is a link to the charger i use for my main battery packs. http://www2.towerhobbies.com/cgi-bin...&I=LXAVN1&P=ML

[jsl]

Batteries...

Heat kills batteries, not everything

[color=#000000]Batteries...

Heat kills batteries, not everything else...

If batteries were ideal, then you would charge your battery with exactly the rated capacity, over any span of time to your liking.

Batteries are however not very ideal. When charging, they waste some of the energy as heat. Charge to hard and the battery gets too hot in the boundery layers inside the battery, most likely damaging it.

A rule of thumb is to charge batteries with 1.4 times their capacity to make up for the energy lost in heat. It also says, that a battery must not be charged with a current more than 1.0 times its capacity, unless it is a special fast charge battery.

Leaving the battery in the charger doesn't always mean that it will be damaged. Most NiCd and NiMh batteries can sustain continous charge at a current 0.1 times their capacity for extended periods of time. The batteri will be kept fully charged, and all of the surplus energy pumped into it will be dissapated as heat.

An example]

[jdbostrom]

Petn7,
I think I might

[color=#000000]Petn7,
I think I might get that charger. Now what I am wondering is]



Edited By JDBostrom on 1110749494

[petn7]

as far as i know,

as far as i know, the charger i use comes with a Tamiya type connector. i ended up keeping the stock plug, but built an adapter that allows me to use my Dean Ultra plugs and Deans microplugs. like JSL brought up, i am losing some energy as heat from the inefficient Tamiya type plug, but i don't care.

as for tx battery care, all i do is do an overnight trickle charge for the first charge on the virgin battery pack, then from that time on i'll just charge at 1/4, 1/3, 1/2 or 1C. for main pack battery care, if i'm not going to use nicads for a period of time, i don't care whether they have some power in them or not, i let them sit. with my main pack nimhs, i make sure they have some juice left in them if i won't be using them for a while. this isn't a problem since i never discharge my nimhs (or cycle them) and just peak charge them when i need them topped up.

currently, i only deal with AAA and AA sized nicad and nimh battery packs. the only nicads i use now are in my tx so i just charge them at 1/4, 1/3, or 1/2 C on a regular non peak charger. with my nimhs, i never charge them over 1C and use my peak charger.

my battery handling practices are probably not the best, but i don't care. i don't need to make my batteries last me for 10 years and i don't need to squeeze every last bit of juice from them.

now with whether or not to get one nimh or 2 nicads for your tx, the nicads with the radio manufacturer brand name were about the same price as the nimhs (at least with the packs i compared). i love nicads and always use them when i can. they have more voltage per cell, are alot more forgiving with bad charging habits/mistakes and are usually cheaper. sometimes, you just need to extra capacity of nimh so i use nimh on my micro sub where space in a premium.

and lithiums...need a little more work before i'll start using them.

here is a link to one nimh that i bought for my tx, but never used

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXBGF7&P=0

if you're gonna spend ALL DAY at the flying field or something, it might be worth getting. but if you're like me and only use your tx a few times a year, forget it.

[jdbostrom]

Thank you. I think I

Thank you. I think I will go with the NiCds.

[jsl]

ehm...

Actually, NiMh are the forgiving

[color=#000000]ehm...

Actually, NiMh are the forgiving ones.. They don't have the undesireable "memory effect" of NiCd.

NiCd and NiMh have exactly the same voltage, but the NiCd are usually better at delivering large currents. This is only important in high current applications. There is no difference when using them in the transmitter.

My little list of cons and pros]