Question about a peak charger........

crazydave · Post by **crazydave** » Wed May 28, 2003 11:59 pm

Well since you guys asked...

I use a charger base from a Cannonball clone. I leave the screws out so I can pop the back off, and I check voltage there. I've been meaning to install mini plugs so I can just plug my probes in, and sit back and watch, but it's gotton so routine, that I just smoke a cig, and then start checking, and it usually starts to peak a minute after that.

Read this thread of mine at TRC. http://tinyrc.com/forums/showthread.php ... eadid=7511
This was a couple months ago, but I go into better detail there, as far as the voltages I was getting, than I have time for right now, sorry,:) but I will say that the batteries have just become more consistant, and have consistantly taken higher voltages over time. The only battery deaths were due to soldering, and shorting out incidences, unrelated to chargeing.

hue35 · Post by **hue35** » Thu May 29, 2003 12:06 pm

Keeping in mind that with fresh batteries in your controller it puts out over 1000mA, I think that 200, 300mA or 400mA is too low for a good quick charge. The way I understand mA in this application is that the higher the number, the more juice you'll get in the battery over the same amount of time. So, you can fill up a battery roughly the same with a 200mA or a 1000mA charger, but at 200mA, it will take a lot longer (which is probably better for the battery, but not for my patience).

In our quest for a perfectly matched pair of cars (or several pairs as it turned out), my homie Superfly and I have tried a bunch of different AC adapters on converted Motor Works chargers. The charger has a 45sec timer and typically we hit it twice for single cell and 3 or 4 times for a dual cell. There was a big difference in performance with different mA ratings. We've tried 800mA, 1000mA and 1500mA adapters... the 1.5A didn't seem to do too much better that 1000mA (plus, it wasn't multi-voltage), but 1000mA was much better than 800mA so we settled on 1000mA multi-voltage adapters. Anyway, Superfly says he's gonna post a step-by-step on the charger, be on the lookout, I like the shiznit outta mine what I cribbed from that biaznitch.

mpbiv,
I've read the same stuff on tinyrc about charging the batteries at the same voltage, but I don't think that's correct. A stock microsizer is charging a 1.2V battery with 3V, and it seems that 4.5V is the best way to charge a dual-cell car (2.4V)... so it seems like a sliding scale as you go upward in voltage, but it looks closer to double the voltage rather than the same voltage.

hue35

crazydave · Post by **crazydave** » Thu May 29, 2003 6:21 pm

I'm totally agreeing with everything your saying, Hue.

I like to think of electricty like water, because they have similar characteristic when decribing them. Think of amps as the amount of water that is flowing, and volts as the strength of the flow, and like water if the flow is strong, then more water will flow. Just like if you increase your voltage with dual cells, you drain your mAs faster. Just a litlle metaphor I like to use.

Using higher mAs will charge your battery faster, which means it's getting fuller in a shorter amount of time. So if your doing timed charges that will make a big difference. If your watching with your volt meter like me, it mostly means I won't have to wait as long. Since it's chargeing faster it will discharge faster. Which means more current flowing from your battery to your motor. If your telling me that the 1000mA has worked out for you, then I think that is the direction I'm going to steer in. For me it's not so much a concern with patience, though I do lack in that department, it's more of an issue of wanting to get the most punch from my battery.

It's just my way of thinking from 1/10th scale that I've brought with me to my bits. I wish I hadn't sold my peak charger with all my RC stuff, and I've been thinking about getting another one for my bit, but it was hard to rationalize for a couple $20-$30 cars, but now it's grown into a collection, so maybe $50 for that Pirahna charger would be a pretty good investment.

mpbiv · Post by **mpbiv** » Thu May 29, 2003 10:28 pm

hue35 wrote:mpbiv,
I've read the same stuff on tinyrc about charging the batteries at the same voltage, but I don't think that's correct. A stock microsizer is charging a 1.2V battery with 3V, and it seems that 4.5V is the best way to charge a dual-cell car (2.4V)... so it seems like a sliding scale as you go upward in voltage, but it looks closer to double the voltage rather than the same voltage.

hue35

Just to to further clarify things, the 3v you say the controller charges the car with, you measured it? I would check it myself, but my voltmeter went kaput. It would sit easier in my mind knowing you measured it

hue35 · Post by **hue35** » Thu May 29, 2003 10:56 pm

1000mA seems to be the right amount, man. I think your water metaphor (a post on tinrc?) is what helped me sort of get the V/mA stuff.

hey mpbiv,

I just put the meter on a stock Microsizers controller just to be extra sure. This one runs 2.98V @ 990mA. A while back I did the hogjowlz 3AA controller mod and I just tested it as well... 4.47V @ 1.76 Amps, perfect for charging a dual cell when the power goes out.

hue35

mpbiv · Post by **mpbiv** » Thu May 29, 2003 11:12 pm

Thanks, looks like I need to revamp my charger once again. I have been trying to get these 40mah dual cell cars charged but so far I am still not getting the run time. Currently I am using 3v at 200mah for 15mins using all those charging formulas found on tinyrc. Maybe next I will try 4.5v and a little more current, or at least get a new multimeter so I can peak charge them like crazydave.

hue35 · Post by **hue35** » Thu May 29, 2003 11:42 pm

One more thought, I didn't like the sound of the "charge it at 4.5V until the batteries get warm" method of charging, before I started running dual-celled cars. 2 or so minutes of a 4.5V, 1000mA charge and you can definitely feel heat at the bottom of the car. I've seen my homie's car get HOT... dude, it was "too hot to handle". Anyway, that car is still running great with the same batteries, so apparently they're not too fragile... 'warm' definitely seems to be a safe gauge.

hue35

crazydave · Post by **crazydave** » Fri May 30, 2003 9:44 am

hue35 wrote:1000mA seems to be the right amount, man. I think your water metaphor (a post on tinrc?) is what helped me sort of get the V/mA stuff.

I glad that metaphor helped someone besides me. I got it from one of the guitar forums when I was learning to build effects pedals.

Here's my point of view on the chargeing voltage. When I'm charging at 3v w/ 2 AAAs, whether I'm charging with strong batteries reading 3.15v, or nearly dead batteries reading 2.8v, the starting voltage is about 1.5-1.6, and the ending voltage is 1.8-1.9. The only difference is the weaker batteries are more erratic, and take longer to reach that 1.8-1.9 zone, but they always get there eventually. Which leads me to believe the ideal chargeing voltage for a single cell is 2v, and the only reason we use 3v is because 1.5 wouldn't be enough, so we take the next step up. That's my guess as to why 4.5 seems better for dual cells, as oppossed to doubling up and running 6v.

Buzzbait · Post by **Buzzbait** » Fri May 30, 2003 9:35 pm

I should have this portable charger completed tomorrow. The charger is switchable between the Bit and Zip Zap charging contacts. It puts out a hair over 200mAH at 4 volts. When I get the new capacitor plugged in tomorrow, it will slow charge with a timer that shuts things down after 13 1/2 minutes. That should provide almost a full charge for a 50mAH car. A 100mAH car will need a double charge.

ezenterprises · Post by **ezenterprises** » Sat May 31, 2003 9:21 am

Where did you get that truck body for the ZZ?

kwikbb · Post by **kwikbb** » Sat May 31, 2003 10:05 am

Hey that's a sweet charger buzz! Yeah i'd like to know a little more about that truck body too, it that a die-cast jeep?

Buzzbait · Post by **Buzzbait** » Mon Jun 02, 2003 7:45 am

Hehehe..... I was wondering if people would pick up (excuse the pun) on that Zip Zap truck body. The body came off of a Kidriffic 4X4 RC, available at TRU. I’ve got two of the Kidriffics. One has that SUV body. The other has a pickup truck body. The pickup truck body doesn’t quite fit on the Zip Zap chassis. The chassis would need to be extended a hair. But the SUV is almost a perfect fit. Very little fitting is required. The Kidriffic bodies are made of plastic, not diecast.

There’s a long thread on the Kidriffic trucks at http://www.tinyrc.com/forums/showthread ... adid=10856 .Once you get some extra batteries in them, they’re a lot of fun.

bitPimps.lixlink.com

Question about a peak charger........

truck?