Squirrels have fuzzy tails.
0 Members and 1 Guest are viewing this topic.
HiI am the author of the popular site, societyofrobots.com.I am a recent customer of this product:http://www.onlybatterypacks.com/showitem.asp?ItemID=10417.7You make a claim for a 35A discharge rate, however my own measurements say its much closer to a 3.5A discharge rate! Just by drawing 2A from a fully charged battery, I already get a 1V drop.I also bought this product:http://www.onlybatterypacks.com/showitem.asp?ItemID=11724.12You make a claim that it can do 3000mah in 1.5 hours. However the above 4200mah takes ~5 hours to charge! The 1.8A selectable rate does not work - it claims the battery is fully charged (within 30 minutes) when it isnt! I have to use the .9A setting for it to work.Either the battery has a charging rate of only 1A, or your charger has a serious flaw.Now I can't recommend your site or products any longer on mine until this problem is rectified and I'm assured this won't happen again. I will also no longer be able to purchase your products, because I can't be sure if the specs are honest.thanks, John PalmisanoRobotics SpecialistNaval Research Laboratory, Washington, DCB.S. Mech. Eng., Robotics, Carnegie Mellon Universitywww.societyofrobots.com
Robotics SpecialistNaval Research Laboratory, Washington, DCB.S. Mech. Eng., Robotics, Carnegie Mellon Universitywww.societyofrobots.com
I use http://www.all-battery.com/ and I've been very happy with their batteries and chargers...- Jon
sorry about that jman571 . . . I got burned really bad - the battery I got I need for my competition in 3 days, but its too weak to power the robot arms on my ERP The arms require 2A peak . . . but drawing just that causes a voltage drop so large it resets my microcontroller . . .Anyway, the battery you posted appears to have very realistic specs. I think you are fine on that. For the charger however, yea, you won't be able to get more than .9A charging rate. It will take about ~3 hours to recharge your batteries. I'll leave it up to you . . .If you decide to keep the battery, I encourage you to multimeter it and see how low the voltage drops when you use it.
Anyways, high current capacity stuff should just be left to the lithiums. LiPo/LiIon provide a lot of energy density and a lot of current. Take a look through Tower Hobbies and the like, and you can find 30C discharge LiPos. However, they are much more finicky about voltages. Overcharge them a tiny bit and they explode. Undercharge them by 0.1V and they stop working (or explode). Drop them and they die (sometimes explode). Charge/discharge them too fast, and they explode. The 30C figure doesn't go together with the lifetime either; discharge them at that rate and you might only get a hundred or so cycles before hitting 60% capacity.
Hi:I took a look at some of these places you have been buying batteries from. I hate to break it to you but those are some high prices you are paying! "www.all-battery.com"wants $26 for a 14.4 Volts 2400 MAH battery. Then they want $14.99 for just a wall charger that can only put out 300 ma. and they called that a sale! Some of the other places you talk about even want more. Shop around guys. I can tell you that I didn't pay anything close to those prices. Also my charger has a base for the battery pack that cuts off if the battery overheats and it can put out 1.2 amps. I bought a few, so if any of you want to buy 1, let me know. BTW the battery pack (C cells) that comes with the charger is 14.4 Volts at 2400 MAH
I paid $11 for my 2400mah 6volt battery from www.all-battery.com I think that's pretty dang cheap. please tell us where you bought your batterys.
easy for u to say, i ordered my battery pack adn charger from the site all-battery pack , it was good only 40$ fro both i proceed to checkout and what do i see international shipments cost is around 60$ what a waste is this economical ordering batteries for 100 $ , better do without the batteries doesnt anyone give free samples??
Yeah I think my total was $44 for battery, charger, and shipping.
I just used an adapter thingy for my charger. (it was free)
Ummm...so it's not such a great deal. I think we all know that you can get NiMH AA cells, but who wants to go through the trouble of soldering them all together then getting a molex connector kit and putting the molex connector on the wires. It isn't worth the trouble and in the end it ends up costing pretty much the same. You can get 12 hitec male molex connectors for $8 and if you want a 4 cell battery pack and each cell is 99 cents that's ~$4 if the connectors are $8 that's $12 plus shipping and you have to do extra work!!!! I would feel uneasy buying batterys and stuff on ebay for some reason.....
I couldn't find a battery holder with the molex connector on jameco.