I'm wanting to buy a new battery for my Nexstar. I'm looking at a Futaba NR4F1500 Reveiver NiCd Flat 4.8V 1500mAh. It calls for a charge of 150 mA 15 hours. The charger I have now for my battery that came with the nexstar says it charges at 100 mA. Would there be any problems with charging this battery with my current charger? Thanks.

I'm no expert:-( But I would think Your charger should be alright..
You may need to leave it charging a little longer than 15hrs to get
a full charge.. But there should be no problems... As long as the
polarity is correct..

from what i have learned, take the current rating of your battery pack (in this case 1500 mAh) and divide it by the current of your charger (100 mAh) and that will give you an aproximation of how long you need to charge your pack (in this case 15 hours). Like I said, I'm not exactly sure, but this is what i've read. someone correct me if I'm wrong.

Your charger should be OK.

Do you want more flying time?

Radio manufacturer battery packs are way overpriced and often not great quality.

Check out Radical RC and Hangtime Hobbies. These guys run small shops and do great work spending the time to make their packs right. They only use Sanyo batteries which are basically the best quality. Prices are very good, especially Radical RC.

I wanted more flying time on my trainer so I bought 2100 NiMH Rx pack and 1650 NiMh Tx packs from Radical RC. Hangtime sold me an overnight wall charger with 120mah output on Tx, and 180 output on Rx. It is $18 I believe. No need for field charging equipment and I can fly ALL DAY!

The cost btween the NimH and NiCd is not much and getting something over 2000 mah is not much more either.

I would go with NiMH, Rx pack over 2000, Tx with 1500-1800 (Tx drains batteries less quickly so you can use lower capacity packs on them).
Your wall charger may not fully charge something over 1500 but for $18 yu can get the one at Hangtime Hobbies.

This was the best thing I've done and the most cost effective.

I have looked into NIiMh batterys and I would stick with Nicads. The NiMh have a faster self discharging rate and don't like to sit withour being used. They also take a few cycles to get back up to full rating after if they have been sitting for a week or so. If you only fly on weekends that means that the Nicads are far better suited to our hobby. If you fly every day then they would be ok. If you are getting into more battery packs of different sizes you may want to invest another 10 bucks over the charger as mentioned above and get a multi charger. It can charge 4 sets at once with different settings. Check the link below.
http://www2.towerhobbies.com/cgi-bin...&I=LXL331&P=ML [8D]

Fastsky -- I respectfully disagree. I use both types & in my experience the NiMh are far easier to live with. I find that they actually self discharge more slowly than NiCds & apparently have no memory effects whatsoever --sitting around doesn't seem to bother them at all, regardless of the state of charge. Best of all, they last a full day of flying on a full charge.

I think that the only real caveat is that they don't have the ability to discharge at the same rate as a NiCd, but for a flight pack, that is not likely to be a problem unless you are trying to run a dozen servos at full load.

I have read comments like yours in various forums, but in practice, where my experience is concerned-- it ain't so. I am steadily replacing all of my NiCds with NiMh.

I agree with Britbrat. I did hours of researching posts and talking to others before buying NiMH and I found that nearly everyone who bought NimH would never use anything else. NiCd are good but if you want higher capacity which equals more flights in a day, than for just a couple of dollars more you can get higher capacity NiMH. Also, for the AA size batteries which is the discussion here, NiMh are able to have higher capacity than the AA NiCd.

Body Pilot, if you only want the 1500 mah range, then you could stick with NiCd BUT a few dollars more gets you 2100 mah NIMH with even more flights on your plane. They will charge with an overnight wall charger like I mentioned before and charge with no more troubles than a NiCd with a wall charger. A more expensive field charger is usually DC powered and you will then need an AC/DC adapter or AC to DC power source to use it in your home. If you only want to fly 1 or 2 planes this is a waste of money and time. I prefer the ovenight wall charger when you only have 1 or 2 planes since you can plug them in and forget about them----no charging worries.

In short, NiCD are good but NiMH come in higher capacities for the same sized battery.

I just looked at the Radical RC site for prices. I received them 5 days after ordering. Great customer service. Very professional quality stuff.

1400 mah NiCd Rx pack----$16.00

2100 mah NiMH Rx pack----$18.00

1100 mah NiCd Tx pack-----$25.00

1650 mah NiMH Tx pack-----$30.00


I have the 2100 Rx pack and can get 8 12 minute flights.
I have the 1650 NiMH Tx pack and will last easily for those 8 flights.

Gee, that sounds quite low, mattbeme. I get far more out of my 2100 mah NiMH rx pack. Are you flying giant or electric???

I tested a 1500 NiMh pack last week and today right after the pack came off the charger. Last week the pack was fully charged on Monday and had been sitting idle until I tested it on Friday. It rated only 1090 mah!!! This was far short of the rated 1500 mah. The only explantion that I could come up with was the 5-8 % daily self discharge rate that is standard for NiMh packs. To try to confirm what had happened the pack was fully charged on the weekend and taken off the charger this morning. This time the pack rated 1585 mah! The charger is an industrial quality charger by the name brand of Cadex. If you have any measured battery ratings, I would happy to read about it but to just say that your high mah rated pack will last a days flying may just mean that they are big enough that the remaining mah left after a weeks sitting is still enough to get you through the day. After my tests I will stick with my 1400 mah Nicads whcih are easily good for the day on any of my planes and I know what I am dealing with![8D]

Zombie, you're right, most planes will actually get 12 flights or so from 2100 mah.

Fatsky, I would never go out flying without having first charged the batteries up the night before.

Don't get me wrong, I'm not arguing about which type of battery is better. Their both great types. My point I guess was that for the same sized battery NiMh come in higher capacities for only a little more money. As to self discharge rates, that should never even be considered if you are in the habit of charging up your batteries before flying. Then, you'll know they're fully charged.

Also, I don't recommend buying batteries from radio manufacturers like Futaba.---assembly line quality doesn't cut it.

Re: "if you are in the habit of charging up your batteries before flying", Right on!!! This is good advice for anybody and should always be done to have a known starting point on the batterys at the field! I have read recently that the man. are thinking of phasing out Nicads so in a few years I may be "stuck" with the newer batterys (good or bad)!!

Phasing out NiCds? I believe NiCds have their place and I'd hate to see them gone for good. If you have a few planes and do lots of field charging you can't go wrong with them.

Fastsky, once you get some 2000+ NiMH packs and a good charger/cycler (Triton class) you'll be wondering why you waited so long.

I absolutely love my setup - 2100 mah NiMH rx and 2300 mah NiMH tx packs. I always charge before going flying - it takes such a short time with the right charger. I can fly all day long and might use half of the packs capacity. In a normal evening at the field I use 300-400 mah. I assembled them myself and they were very inexpensive.