New battery charger help me with the settings

[mikegigabyte]

So my dad comes over with a brand new Losi MRC, I'm still waiting for mine to show up.
Anyways the guy at the store convinced him to buy a intelligent digital balance charger for $75. Name on charger says Thunder AC6 Dual Power. My dad also got one for me, so were trying to figure out the settings for the losi nimh battery. The instructions suck for a beginner. The charger must be a no name brand as the pic on the box doesn't even have the charger name on it, nor does the instruction booklet, and it doesn't go into much detail on the battery settings. There are settings for amps,battery type etc... I set it to nimh, put in 3.5 amps but I'm confused on a few other settings. From what I could figure out from a chart is for my 6 cell 7.2 volt I can charge at 5 amps. When charging at 3.5 amps I took the battery off after 10 min and the battery was hot, after driving the truck for about 30 min I put back on charger and this time it completed the charge in 10 min and I had a fan on the battery at 3.5 amps. It said fully charged and battery was cool, but I had the fan on it.

So what I assume is I can charge at 5 amps, and I guess the battery will charge quicker, but will get hot? Should I charge at a lower amp? Will a lower amp take longer to charge?

Another thing the guy who sold it says yeah it comes with all adapters and your battery should hook right up, well he was right it has a ton of adapters, glow plug, alligator clips, some circuit board with 5 different adapters on it, some pigtail adapters all those but the losi battery one. We cut the end off the losi charger and used the alligator connector and used it that way. I will charge my glow pulg on here too, found how to set that for a nicad battery.

Here are my main questions
What setting for my losi 7.2v nimh and do I need to set for charging ( amp setting), I dont mind waiting 15-30 min charge time

The discharge setting,what is a good discharge setting. It has options for that too. When do I need to discharge.


Found the charger online if it helps http://www.hobbypartz.com/thac6smbachw.html


BTW the Losi MRC is pretty fun so far, in the backyard on some bricks.

 

[Metalhead Matt]

What's the mah rating of the batteries your using? The rule of thumb is, for example, if it's a 3000mah bat, you charge it at no more than 3 amps. If it's a 4500, 4.5 amps. 1500, 1.5 amps. The battery should get warm, not hot. No more than 120 degrees. Smaller batteries get charged at lower amperage. Like a 1500 2/3a cell pack(like the hump packs you use for A tmaxx radio system) would get charged around .8 amps. Edit: That's a damn nice charger. My buddy has one and it has worked great for about a year so far. He only charges lipos on it. One more thing I'll add, just out of personal preference, I always charge on the slow side. 5000mah pack, 3 amps. 3800, 2.5. 4600, 2.8. Nothing I just put up is in stone; just what has worked for me.

 

[mikegigabyte]

What's the mah rating of the batteries your using? The rule of thumb is, for example, if it's a 3000mah bat, you charge it at no more than 3 amps. If it's a 4500, 4.5 amps. 1500, 1.5 amps. The battery should get warm, not hot. No more than 120 degrees. Smaller batteries get charged at lower amperage. Like a 1500 2/3a cell pack(like the hump packs you use for A tmaxx radio system) would get charged around .8 amps. Edit: That's a damn nice charger. My buddy has one and it has worked great for about a year so far. He only charges lipos on it. One more thing I'll add, just out of personal preference, I always charge on the slow side. 5000mah pack, 3 amps. 3800, 2.5. 4600, 2.8. Nothing I just put up is in stone; just what has worked for me.

Its the stock losi battery, all it has is 1100. I assume thats the mah.

 

[Metalhead Matt]

Yep. And if it's a mini, it's probably the A2/3 cells. Considerably smaller than sub c's(like the pack to start your maxx). Charge that around .8 amps. Hate to say it, but if you charged it a couple times at 5 amps, it's probably damaged. You may not notice, though. Luckily it didn't pop a cell or 2. Your hobby shop guy needs a swift kick for not explaining things better. Good news is that you can get packs for those mini crawlers for pretty darn cheap. Check around for packs from after market companies or scope out the rock crawling forum and hit them guys up. It should take around 45 minutes to charge that pack when it's pretty dead. As soon as you notice any decrease in power, let it cool all the way and then charge. Don't run nimh packs all the way dead or you could ruin them. A fan isn't a bad idea, but it could fool you into thinking the packs cooler than it is. Always stay on the safe side. If it's warm after a run, let it sit in front of the fan for an hour or so and then let it sit for a few minutes with the fan off. If it's room temp, your good to go.

 

[mikegigabyte]

The first charge was for 10 min at 3.5 amps and got hot, the second charge was also around 10 min with a fan. Not super hot, just you could feel the heat in the hand. Hopefully those two times didnt do much damage. I've been running it for 6 hrs now on that same charge off an on, still going strong. Trying to see if I can get it low enough to do a full charge. Thats why I wanted the correct charging info.

No matter what if I keep the power low the better it will be for the life of the batteries. I think the next charge will be at 1 and I will monitor the heat. The charger does have a remote temp sensor you can strap on the battery while charging, and you can set alarms if it gets to hot, and I think it may also shut down the charger.

 

[Metalhead Matt]

As long as you use a nimh pack often, there's no need to run it down. They can be charged anytime, as long as they're not warm. Every 10-15 uses, a cycle may help. Never drop a nimh pack to below .9 volts per cell. 7.2=5.4. Sounds like your battery is fine, though I think that 1 amp is still a bit high to charge at. Try between .6-.8. It makes a difference. Especially in those small battery packs.

 

[mikegigabyte]

Thanks for the info.
One more question, looks like I only have the choice of charge/discharge or discharge/charge when I select the charge button.
Then it wants the amps, and volt for the discharge. I set it on discharge/charge that way I guess it will discharge then charge it but what should the amps and voltage be. The same as charging. Right now I have it set very low for both now maybe that will make it take longer to charge because it will take forever to discharge.

 

[mikegigabyte]

Hey my losi quick charger came in today, so I looked at the charge output, it puts out 1.2 amps, so I would think I could set my charger at the same amount and be safe, since losi does it.

My dad is going to return his charger and use my losi quick charger, when I charged the batteries at the .6 amps as recommended here it took almost 1-1/2 hrs. This losi charger says 1 hr charge with trickle. Since this is the only battery my dad is going to use might as well save some money and return the digital charger. I've decided I'm going to use the lipo batteries as it came free with my truck and also came with the servo mount so I can mount it up front. Also since my dad bought me my own digital charger I can use it with the lipos and nimh. Already charged the lipo and it took 45 min with my new charger.