Can a battery cause the ESC to shutdown?

[cmu3rd]

Can a battery cause the ESC to shutdown? I use two 2C Lipo batteries for my Traxxas Slash Ultimate. I have only maybe 20-30 cycles on these batteries. I store them properly with a storage charge. One battery only lasts a minute or two and the the ESC shuts off. The other battery runs for 1/2 hour at least. When the car stops I can't turn it back on. If I disconnect and reconnect the car will turn on but die the same way. I have checked temperatures and everything is less than 100 degrees. So it's not heat. The battery measures almost full voltage and will recharge in minutes so it's not discharged or low voltage. The batteries are Lectron ProAny ideas?
Thanks,
Chris

 

[bill_delong]

absolutely yes... I've had batteries fail at kinds of various scenarios. Typically they age out and lose punch, but not uncommon to have internal wiring issues or even a cell go bad. If you have an IR meter on your charger, that will be a dead giveaway to identify a weak cell.

Just because you may have only got 30 cycles on a battery doesn't necessarily mean a cell has gone bad in the rare case you got an aged pack that may have been sitting on the shelf for years on end. It would be nice to see a manufactured date stamp on all batteries to get a better idea of the quality where I prefer to discard any of my batteries within a year of use for peace of mind, regardless of how many cycles I've put on the packs. Same goes for the batteries in my cordless drills, etc..

 

[Jamr]

Connect each battery to a good charger or battery checker and look at the voltage and resistance values for each cell.
If you have a bad cell, time to recycle it and get a new battery.

 

[cmu3rd]

I have mesasured with a volt meter each cell and they measure the same both before and after the failure. I am not familiar with measuring the resistance values. Need to google what they should be. I don't have a battery checker but I do have a good Dynamite charger which isn't complaining. I even did a discharge down to 7.x volts and balanced charge back up.

 

[bill_delong]

I talk about the importance of IR measurement here:

• Which charger is the best?

 

[cmu3rd]

Nice article. So I did some research on IR and my charger actually measures this. The bad pack is 10mA and 8mA. Both > 7. So this is obviously my issue. Thanks for your input. Every turn in this hobby I learn something new. Now I am in the market for a new battery. Any advise? I only run a few times a year when the grandkids come over so the batteries spend most of the time in storage. I currently run 2S so the kids don't destroy the truck but thinking about 3S for me.

 

[bill_delong]

There's a great post here comparing several brands of batteries to consider:
https://www.rctalk.com/forum/threads/lipo-comparison-thread-lipo-and-nimh-aas.136829/post-1368906

For the price, I've been happy with Zeee brand batteries myself but they are not very high on his chart, I would look over his top performing packs and probably go with one of those toward the top of his list on the second section of the chart with the high current draw.

 

[cmu3rd]

Thanks again. I like the price of the Zeee. Lectron Pro isn't even on the list It's the brand my local RC dealer sells. One review online said they start out with high IR. So I took a another look at the good and bad batteries IR again and they measured the same at 22 and 20 per cell. So maybe this isn't my problem or the good battery is close to failure.

 

[RustyUs]

Nice article. So I did some research on IR and my charger actually measures this. The bad pack is 10mA and 8mA. Both > 7. So this is obviously my issue. Thanks for your input. Every turn in this hobby I learn something new. Now I am in the market for a new battery. Any advise? I only run a few times a year when the grandkids come over so the batteries spend most of the time in storage. I currently run 2S so the kids don't destroy the truck but thinking about 3S for me.

To me, a 2mΩ difference between cells is not a big deal. Even a pack with cells having an IR reading around 10mΩ I still use. I'd be more concerned when cells age faster than others and have a greater IR differences e.g., a two cell LiPo pack with one cell IR reading 3mΩ, and the other cell is at 12mΩ... you know something is up with that pack (most of the time). The cells with the higher IR readings are usually the ones that reach each end of the voltage scale the quickest.

The IR measurements on chargers are only to be used as a tool. They are not extremely accurate. A person can often get different readings when doing IR measurements consecutively. The key to getting similar/more accurate readings is to take readings at the same point in LiPo use. My chargers only give me an IR reading during the charging process, so I go with those numbers at the end of a charge, or close to end of charge as the packs are at their warmest. Keeping an eye on pack's heat, voltage at end of run, and time it takes to balance cells will help warrant the need to replace battery packs.

Yeah, 20mΩ IR cell readings would put me in searching for a new pack.

 

[bill_delong]

I can assure you that 2mΩ difference between cells is staggering.

I find it best to check my IR immediately after a full charge on high current to get the best IR readings.

I suspect the bad battery in the OP's case was likely an aged pack that may have sat on the shelf for too long.

I have owned LectronPro in the past and they performed well for me for a solid 6 months of use in my 4WD SCT which is about the average lifespan of most batteries I race with where my packs see hard abuse on a large 1/8 track with lots of big jumps and extreme heat in the outdoors in Texas.

Again, the benchmark to be considered "low IR" is 3mΩ where most packs will read close to 1mΩ when new, most racers in my area will discard a pack when any cell goes above the 3mΩ mark, I personally use 7mΩ for my threshold. The OP is reading 10mΩ which well past the "safe zone" in my book.

It's not a ding against the manufacturer either, I just make sure to buy from sources who deal with high volume so I don't risk buying a "stale" battery that may have sat on the shelf for too long.

 

[F.R.S. Ninja_007]

Get a quality battery like gensacearespammers (and also make sure it fits, I needed to get #TRA7426X for larger batteries). I got some venoms and they work great, I don’t really care if it’s mediocre performance compared to others bc I can share them with other trucks.

 

[bill_delong]

There are only 3 brands of batteries that I would discourage people from buying:

1) Gens-Ace - They burned me on a lost leader sales tactic scam, also notorious for premature internal wiring failures
2) Max Amps - Grossly overstating C ratings and were the main reason URC was shut down
3) Traxxas - Proprietary designs preventing compatibility and creating a monopoly

 

[cmu3rd]

Thanks everyone for all your support. I have recieved an education in Lipo batteries and picked up some great tips. I like to support my local RC shop so I decided to go buy new batteries even though the batteries don't get the best reviews. I am not a racer, just a basher. and mostly young kids as drivers. I took the problem battery with me to see if they could test it. They tested with a meter and found the same high IR but when they put it in a Slash guess what they found. A bad adapter for the XT60 to Traxxas connectors. The pin on the male side just needed a little expansion. Battery ran fine for 1/2 hour yesterday. I guess there were some small tollerence differences between the two battery connectors causing the same battery to fail everytime. This explains why the battery could discharge and charge fine on the charger. It pays in more ways than one to shop local if you can!! My local shop is RC Car World in Cinniminson NJ and I would highly recomend them. They have provided me great support on multiple occasions.

FYI, the new Lectron Pro 2S 35C has a IR of 5 for each cell when fully charged so 10 may not be that bad for these batteries atleast when measuing life expectancy.