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View Full Version : Need some advice on 900 MAH cells...


pgeldz
2010.06.11, 09:35 AM
Hey fellas,

I wanted to run something buy you guys since you probably have a little more experience with these different brands of batteries...

Our normal races are three 30 lap heat races, and you have to use the same batteries for each heat. Each lap is approx 13-14 seconds. Using a worse case scenerio, it comes to 21 minutes of racing.

I wanted to know what batteries you guys would think would last for that long...

None of the 750 - 800 MAH's will make it. We've tried R1 Works, Intellect, Much More 777s, Orion (both SHO and HV), Lexel Spark A, Squat, Atlantis, and Sanyo eneloope. The Sanyo eneloop's last the longest, but they are also have the least punch. They are smooth though and have good top speed. They almost act like a 900MAH. Still, all the brands mentioned above in 750-800 capacity all fall short during the last heat race.

The 900 MAH's are better. The R1 Wurks almost make it, and other than those, most people are using Much More 900 HPC. I've bought a set of the Much More 900 HPC for testing and they feel very, very similar to the R1 Wurks 990s, but haven't actually tested them to see if they actually make the 90 laps/21 munutes at race pace.

Do you know of any other 900MAH capacity batteries that may make it?

I do have a set of older Orion 900 RT that I think will definitely make it, but they are slow as hell. Consistient, but slow. I'm looking for something with a little more oomph, like the R1 Wurks or Much More HPCs.

So far, I've found that Orion makes a Green label 900HV in 1.25V, which look like it replaced the older 750 Green Label HVs which were 1.2 volt. The old Orion 750HVs are awesome cells, and are what most folks use to qualify with. Are the newer 900HV 1.25V similar with more run time?

The only other cells I've found were Peak Racing 900s, TRP 900s, and Team Scream 900s.

Do you guys have any experience with those? If so, can you summarize their characteristics for me?

I appreciate all the help fellas. Look forward to your response.

Best Regards,

- Paulie

mk2kompressor
2010.06.11, 09:51 AM
what motors are you running?
we ran the 12hr race in germany with duracell 1000mah and got up to 40mins runtime no problem

pgeldz
2010.06.11, 09:53 AM
what motors are you running?
we ran the 12hr race in germany with duracell 1000mah and got up to 40mins runtime no problem

We use the Kyosho X-Speed motor exclusively.

- Paulie

mk2kompressor
2010.06.11, 10:06 AM
i take it 2wd chassis too?
what rates do you charge at?
any conditioning?

pgeldz
2010.06.11, 10:15 AM
i take it 2wd chassis too?
what rates do you charge at?
any conditioning?

Yes, 2wd chassis.

All charging is done on a Dynapower Perfect Charger by Seiki. Charge rate is 1.0 amps, and I run the batteries out until the car won't phyically move. When I charge them I use the refresh feature to fully discharge them, than charge them.

I so this everytime I charge a set of batteries.

With that said, do you thiink the Team Scream 900s, TRP 900s, or Orion 900HVs will be good? Can anyone tell me the characteristics of each?

- Paulie

mk2kompressor
2010.06.11, 11:06 AM
try .5A for the charge rate, even the 750sho's will go further at a lower rate (you shouldnt go 1a on those anyway)
cutoff @.3v if its adjustable and discharge @1-2a depending on your charger specs.
that will give you more runtime, orion 900hv will be good for the punch and runtime you want

pgeldz
2010.06.11, 08:25 PM
The Dynapower Perfect Charger by Seiki is not adjustable...

v/r,

- Paulie

EMU
2010.06.11, 09:06 PM
Dont drive your car until it doesnt physically move. Its not good for your cells. When you have a noticable slow down, and the car dumps, you shouldnt run anymore. That means one cells has completely discharged, and you are essentially running on 3 cells. Continueing to run the car could cause you to overdischarge the lowest cell, and lose capacity and punch.

What discharger do you use? Do you have any other batteries to test with? Does your charger tell you how much charge is put in to the pack when they are charged? What does it say for the cells you are using?

pgeldz
2010.06.11, 09:24 PM
Damn,

That makes a lot of sense (not to drive until the car stops). I should've known that from 20 years of conditioning my Sub C cells for 1/10 touring.

Duh!

Makes perfect sense though. I'll bet some of my cells have discharged to much because of that, and maybe that's why I'm not getting the run time I need.

I discharge using the Dynapower Perfect Charger by Seiki, using the "refresh" function. This charger does not give you any readout on the cells, but I like it because it charges (or discharges using the refresh button) individually.

So from now on, I'll stop driving the car when it's noticable slow down, and then put the cells on the refresh funtion, which will discharge them individually, then charge them back up individually to their full capacity.

I guess I was thinking that they'd get a memory effect if they weren't fully discharged, but since the refresh funtion does that anyway, it's not important that I drive them out of juice completely, because like you said, I could be over discharging a cell or 2 that way.

I have some new cells on the way, so we'll see how it goes.

:)

- Paulie



Dont drive your car until it doesnt physically move. Its not good for your cells. When you have a noticable slow down, and the car dumps, you shouldnt run anymore. That means one cells has completely discharged, and you are essentially running on 3 cells. Continueing to run the car could cause you to overdischarge the lowest cell, and lose capacity and punch.

What discharger do you use? Do you have any other batteries to test with? Does your charger tell you how much charge is put in to the pack when they are charged? What does it say for the cells you are using?

EMU
2010.06.11, 10:18 PM
If you plan to get a new charger any time soon, I recommend the LaCrosse BC9009 or Maha MH-C9000. You get readouts for all of the cells for their discharge and charge cycles.

I personally dont discharge too often. I usually discharge ever 5 uses, mainly to check the numbers on the cells to check the capacity that the cells have so I can remove ones that are low. In general, the less you use the cells in a race day (full charge/discharge), the faster the cell will be. If you want to discharge, do it after you plan not to use the cells anymore that day. Otherwise you are overworking the cells. If you plan to prepare cells for a race, do it a couple days in advance, so the cells have time to rest.

pgeldz
2010.06.11, 10:32 PM
Yeah, I only use a set of cells once per day, once per week, so that discharge, charge cycle gets done once per week. I do it usually the day before the race, and then put back on the charger the day of to peak them out.

- Paulie

pgeldz
2010.07.03, 08:17 PM
Quick update fellas...

I finally received all my cells. The last batch came yesterday. I had a chance to run the Orion 900HV's, Orion 750HV's, TRP 900's, , Much More 900 HPC, R1 750's, and R1 900's.

The Orions (both 750HV and 900HV) felt very similar. Great punch and top speed, but at the expense of longevity. The R1 750's felt very similar, with slightly more punch (almost too much), but around the same top speed. Again, at the expense of longevity. To my surprise, the R1 900's were very similar to the R1 750's, but lasted about 25 laps longer. The TRP 900's and Much 900 HPC's were phenominal. They are hard to describe, but they felt extremely smooth and consistient through the whole run. Punch and top speed were there, and they lasted the longest in my subjective testing.

For racing with our X-Speed motors, I'd say the R1 900's, TRP 900's , and Much More 900 HPC's were the standouts. The R1 900's have crazy punch in the beginning, and it tapers off after about 5-10 laps on our track. The TRP 900's and Much More 900 HPC's are somwhere in the middle of that, but they are like that the entire run from start to finish, again, extremely smooth cells.

The only other cells I've yet to test are the Team Scream 900's. I just received 3 sets yesterday, and plan to test them this weekend. They are the brand new cells in Grey/Silver shrink wrap. I'll let you know how it goes...

Oh, and I picked up a 1.5A individual discharger with auto cutoff to discharge my cells with, as I think the refresh function on my charger has a very low discharge amp rate.

:)

- Paulie

Felix2010
2010.07.04, 12:18 PM
Great reviews Paulie, thanks for the info esp. the MuchMore cells. Have you tried the MuchMore 777 cells yet? Just curious, I have not been able to get any.

I keep hearing great things about the TRP 900 cells. But I am a fan of Orion cells most, the 900's are amazing to me and so are the Orion 750's, when you single-out 4 outstanding cells out of a few packs or Orion 750's they can be UNBELIEVABLE.

Thanks again, hope to read more battery info from you:D

pgeldz
2010.07.04, 12:44 PM
Great reviews Paulie, thanks for the info esp. the MuchMore cells. Have you tried the MuchMore 777 cells yet? Just curious, I have not been able to get any.

I keep hearing great things about the TRP 900 cells. But I am a fan of Orion cells most, the 900's are amazing to me and so are the Orion 750's, when you single-out 4 outstanding cells out of a few packs or Orion 750's they can be UNBELIEVABLE.

Thanks again, hope to read more battery info from you:D

They have the Much More 777 HPC+ at my local hobby shop, but no one runs them for some reason. Supposed to have good punch, but short run times. They also sell the Orion 750HV's, and they have just as much punch (if not more), and last longer so maybe that's why no one really uses the MM 777's.

I will be trying out the Team Scream 900's tomorrow, so I'll let you know how it goes...

:)

- Paulie

byebye
2010.07.04, 01:10 PM
Your next purchase should be one of the charges EMU recommended. I have both and love the read out feature they have. They both tell you the MAH each cell has charged up to so you have an idea if a cell actually needs to be discharged and recharged. The Lacrosse chargers will allow you to insert the battery to quick check the voltage.

I generally charge my batteries before race days at 200mah-500mah. I've seen capacities as high as 1100mah on 900 orions and usually charges take around 30-45 minutes(I have two lacrosse chargers and one maha) . I also generally match cells. Also when you run a set of batteries check the voltages afterwards to make sure that a cell didn't die early. You want to weed those out of your collection.

Kris