george fisher

I have a T Rex 600 with The 5000ma battey. The battery will not take a charge and recoginzes the battery as only 5 cells instead of 6. Is this a charger problem or battery problem?

guver

My Feedback: (325)

I thought the 989 required the user to input the cell number in. If you've done that and it is showing the wrong number of cells or an error then I would stop and check each individual cell in the pack to make sure none are too low. If they are all the same then perhaps you can input 5 cell and start chargeing.

Tim@MRC

If you input the cell number as a 6 cell, and the voltage on the battery is really low compared to what it should be, then the charger may very well only recognize it as a 5 cell. At that point, you may get an error telling you the battery voltage is too low. This is a safety feature built into the charger. This is to avoid a mis setting and possibly over charging a battery. What's th voltage in the battery before you tried to charge?

ahr43

Hi Tim[at]MRC,

What is the power draw in watts of the 15V/10A power supply?

Our calcs came up with appx. 23w. Is that close?

Team AHR43 is trying to decide whether to go with a power inverter or a gas generator to provide pit power. Know the 989 wattage rating will help us decide. Thanks.

//AC//

Tim@MRC

The most wattage that the power supply would draw would be 150 watts (15 volts at 10 amps). However, for R/C car stick packs it would be more realistic to see 40 to 60 watts.

dark96

I was wondering if anybody else had this problem when charging a nimh . i was charging my 3800 NiMH duratrax battery and noticed that it went past the set 3800 mah mark i had programed, and didnt stop charging. I was just curious is there something else I need to setup on there or is this normal and I need to keep an eye out for it? I didn't hear it beep when it hit the 3800 mark either was the problem. just curious..thanks...also what should i set the cutoff peak mV @ i dunno if i have that part set up correctly..cause in the manual it says 5 v per cell, so should i set it up @ 30 mv?

guver

My Feedback: (325)

It's not really a problem , but rather can charge to 112% of capacity. It's not adjustable and I have one going right now to test the figure.

I'm guessing a 150-200% of capacity safety is built in. The correct way to terminate is to rely on the peak detection rather than capacity. A super dooper brain would take into account the rate vs capacity and adjust the max % accordingly. Maybe have to allow the engineer to chime in about that one.

EDIT: tested twice at 112% of capacity setting while at max rate of 4C.

dark96

so in otherwords there isnt much i can do? what bout the mV cutoff? any suggestions as to what i should set that as on my 6 cell nimh am i right in guessing i should set it up @ like the manul says @ 5 mV per cell? and what were u charging btw?

guver

My Feedback: (325)

I guess I'm not understanding what it is you'd like to do with it. If perhaps you'd like it to shut off right at 3800 then a capacity setting of 4256 could be used.

The capacity cut-off is merely a "safety stop" or a "backup" and should not be used normally. The peak detection (mv value) is what is normal for stopping charge. It is set as a "per cell" value so set it to 5 mv.

ps I happened to be chargeing a 6 x 3800 nimh and the stop code is C.2 when the capacity stop has been reached. Your particular battery might just hold more than 3800 mah and if so it is a good one.

dark96

i guess what my main question now is is what to set the peak dectection at...and i guess if i set it for 5 it will mean per cell in the charger. i sorta confused myself there and thanks for all the hely guver.

guver

My Feedback: (325)

Yes, you got it. It can be confusing because some chargers want a total value and some need a "per cell" value. This 989 uses a per cell value and then probably multiplies it by the number of cells that you input into memory. The previous 959 and 969 and 977 used a "total" value.

Tim@MRC

The capacity setting on the 989 is more for setting the profiles and charge settings. This is to confirm that you have the correct battery connected for the charge settings selected. It is very common for a battery to go over the rated capacity, sometimes by as much as 5 - 10 %. As far as the delta peak setting, you can use anywhere for 5 - 10 mv per cell, but I tend to be a little conservative here and I use 5 mv. You can use the 5 mv per cell, and then by checking the charge capacity and the final temperature of the battery to determine whether the battery is fully charged or not, and then make any adjustments to the mv setting then. A higher setting makes the charge less sensitive to peak, while a lower setting makes it more sensitive to a peak.

ahr43

We were way off trying to determine power consumption using an Ohm's law circle. We went back to our RS Basic Electronics book and are now using the power circle. Thanks, Tim.

Does the 989 SuperBrain have any specific requirement for type of 115vac input? Specifically, is Modified Sine Wave/Semi-Sine Wave acceptable, or does the 989 require [Full] Sine Wave for an input waveform to the power supply? Does it matter?

Also, will the 989 trickle charge a full size AGM (Absorbed Glass Mat) battery?

We are still gathering data on inverter vs. gas generator use in the pits. We really want to make a case for a 1500W inverter powered by an auxillary AGM battery instead of a 1000W gas generator. However, the Honda EU1000 generator we are looking at features full sine wave output. That makes it a better match for the 989?

Here is the link to our source information: [link]http://www.almac.co.uk/proven/Inverter2%20Battery%20charge%20.htm[/link]

//AC//

Tim@MRC

How many volts id the AGM battery? Why not hook the chargers directly to the AGM battery?

ahr43

12vdc x 95ah (ampere/hour). Primary method of recharging AGM battery will be our truck's alternator system while en-route return from race site to home. We always like to have two ways to do something. Alternate method of recharging AGM battery will be 989 in trickle mode at home site? We are looking at a 'Power Patrol Sealed Lead Acid (AGM) battery offered by Interstate All Battery Center here in H-town. They have AGM-specific [trickle] battery chargers on the shelf for sale. We don't want to buy another battery charger for the AGM if the 989 will do the deed.

Here is our source link: [link]http://www.batterystuff.com/tutorial_battery.html#3[/link]

Tim@MRC

So then yes, you can use the 989 to put a charge into the AGM battery. It's just going to take it a long time to fully charge it. I would still rather see you hook the 989's direct to the AGM to power them up at the track, rather than using the AGM to power an inverter than plug the 989 power supply into the inverter.

ahr43

Tim,

O.K. on charging the AGM battery, realize it will take some time to complete the charge-up. Just want it as a option.

Sure! Never really thought out-of-the box enough to hook the 989 direct to the battery. As we recall, our 989 package didn't come with a battery terminal connection provision, so never consisdered going direct to a 12vdc battery source. O.K., we'll try that option. We love options! We'll simulate that by hooking the 989 to the 12vdc hot box we have in the shop. Previous experience we had with a competitors charger was that 12vdc wasn't enough "push", e.g. voltage, to fully charge an 8x4200, or even an 8x2200 battery pack. We needed more voltage, such as the 15vdc the 989 115vac power supply offers. That is why we were stuck on the inverter/115vac feed to the 989 power supply. We'll try your recommended work-around and let you know. Again, thanks for the reply and assistance.

We'll still need the inverter to power up our soldering station and pit lighting, but those are seperate power requirements outside the discussion on this thread.

//AC//

Tim@MRC

Are you charging 6 cell packs or 8 cell packs? The 989 has a "boost" circuit, which allows it to charge a high voltage pack from a 12 volt source. So even if you're charging an 8 cell pack, the 989 should have no problem providing at least 5-6 amps to the pack from a 12 volt source. Also consider this, the AGM battery is approximately 95Ah right? You're charging 4200 mah and 2200 mah batteries, right? You can charge about 22 of the 4200, or about 43 of the 2200 before you would kill the AGM. If you can spare it, you can even run 2 AGMs in parallel to double your capacity.

ahr43

8cell packs. 8x4200 and 8x2200. Great info! From what we read, the 989 will "boost" our 8cell pack off our 12vdc truck battery for club meets, e.g., 2.50sec [E.T.] Index Class. Perhaps even for IMDRA sanction meets where we run Bracket Class at 2.42sec E.T., give or take. No need for an aux. inverter. O.K., we're diggin it!

Sorry, 2 AGM's at $200 a pop exceeds our racing budget for now. But, we'll keep the recommendation in mind.

Good stuff, Tim, thanks. We'll digest this and apply it and see how it all shakes out.

//AC//

Tim@MRC

No problem...FYI - I just tested it to see what I would get. I was able to charge an 8 cell pack at almost 7 amps from a 12 volt car battery. And the car battery was reading under 12 volts. So that's not too bad. Yeah, those batteries are expensive. Your 989 didn't come with 12 volt clips? They should connect directly to the banana plugs on the charger. They would've been in the same bag as the little metal stand and the Velcro strap.

ahr43

Duuh! Yeah, Tim the 12V clips came with the charger. My bad. They went into our pit box when we installed Sermos/PowerPole connectors on the input side of the charger. We attached dual leads to the plugs; one Sermos/PowerPole, and one Tamiya std. That way we can run two chargers at once off the MRC power supply. Must have been having a 'senior moment' and didn't tumble to, "Hey this will work with a 12V battery too..." sorry.

Next challenge we need help with is the little green output plug. For field use, the wires just won't stay under the hold down screws. They always seem to come loose when we're frantically trying to re-peak between rounds of drag racing. 39.08V indicated on the charger when that happens. We've cut off and re-soldered the ends; even used heat-shrink tubing and a length of 12ga insulated wire to support the output leads in hope of taking the strain off the little green connector. Nada work.

Is there an engineering fix in place for this, like maybe a molded plug assembly? We're ready to try removing the case cover and hard wiring directly to the board next. What are your suggestions or remedies, or is this an isolated case?

A removeable plug is not really necessary for our application. FWIW, and IOHO, we'd rather have an industry standard Tamiya hard wired to the charger board. We can attach adapters to that. Oh! And, a backlit display would be nice for night racing. Might you all have that available as a customer-install option?

Glad you're here online to support us.

Regards,
//AC//
Team AHR43

ahr43

Hi Tim,

Bad News. We've moved our 989 to back-up charger status. TWICE between qualifying rounds last Saturday, the (+) lead on the little green plug came loose and disabled our re-peak and put us in a tight spot. We're using it to charge our receiver packs, an essential but low-priority mission. We're using our Tekin BC-112A again as our primary charger.

Is there a moulded version of the pesky, troublesome little green plug? We'll hold tight with it the way it is until after the IMDRA World Finals in Oct, then we're going into the case and hard wire output leads in hope of curing this re-curring problem once and for all.

BTW-we wanted to PM you on this, but that service was not available. We really dislike posting this in the open, but we need help with this.

Regards,
AC Hauswald
Team AHR43

PacificNWSkyPilot

My Feedback: (19)

Clips? Little metal stand? Velcro Strap? Little Bag? I knew that something was funny with my 989 charger. It LOOKED like it had been opened and used at the hobby shop, and the owner said no, that's the way it came. NONE of that stuff was in with it, and this thing has killed two batteries in a row (The first two I tried to use it on). I'm scared to use it, and I think there's probably a good reason. I think somebody bought it and took it back to him and he threw it back on the shelf rather than having it checked out. Who knows what the first guy did to it before returning it? This thing kills LiPos like crazy. Neither LiPo was puffed, neither LiPo was hot, neither was run down too far, it showed both having a low battery error, and when I looked at them shortly after they were puffed.
Both batteries were BRAND NEW.

Jim

Tim@MRC

Wow, sorry to hear about the problems you're having. Can you send the charger in to us to check out? Also, inlcude a note explaining the problem, and that you didn't get any of the accesories, and I'll make sure you get them.

Tim Sandor

msd_q

i buy MRC Super Brain 989

but unfortunately

1- the DC power supply its explosive (damage ) in fist time when I connected to 240v I don't know why ? thay say its work with 120 to 240v ??

2- before I have TRITON2 it was perfect and its charge full battery capacity without make my battery hot but with 989 its not charge full capacity for my battery and its make my battery very very hot

best regard

musaed