Weird battery behavior (first time this happened to me)

[Reezo]

Hi everyone,

I have two Tattu 4S LiPos (1800 mAh 14.8 V 120C) that is behaving normally, minus one - not irrelevant - detail.

I had charged it a day ago to use it as backup in my trail run, but ended up not using it. I connected it yesterday to my iMars D300 charger, it showed as fully charged. And I ran a "storage" program on it, to bring it back to 3.8 V per cell, at a rate of 1800 mAh (1C). I went back to check on it this morning (I let it run overnight) and the cells now sit at 2.8 V each. I am now running another Storage program, always at 1C, and the battery is charging nicely, no issues.

No other battery I have, exhibits such a behavior. Once the storage program is finished, they all sit at 3.80 V, whether I take them off the charger right at the end of the program (with its 'beep!') or hours later.

Thanks for your help, as usual!

 

[cul8tr]

Tattu 1 brand I stay away from.
New battery 3s 1800 75c didn't last 20 mins on the trail and c rating should've been 10 barely any punch.

 

[Reezo]

Tattu 1 brand I stay away from.
New battery 3s 1800 75c didn't last 20 mins on the trail and c rating should've been 10 barely any punch.

What brands would you recommend? I am also having issues finding "the best" battery that can also fit my Capra tray, but will do ok on short trails or better: comp crawlers. I don't want to run 850 mAh 4S on the Capra when we take it on trails, so the "biggest I can" is still an ongoing quest. I know, it's probably going to end in "bring many small batteries, that's how the Capra works".

Thank you for letting me know. I got these for free and I cannot complain for what they have been doing but I've maybe gone through 4 charges totally. I might put them for sale and get something else, I am usually running bigger packs than these on trail trucks and smaller ones than these on comp crawlers, so it's also an in-between size I don't really have use for.

 

[JatoTheRipper]

Isn't Tattu part of Gens Ace? I've always had great luck with Gens Ace until they priced themselves out of the cheap market. Now I go to HobbyKing for most of my batteries.

On my Capra thread I am running Goldbat 3S 1500mAh LiPos. I ran my Capra once, years ago, so I can't give any input into long-term durability of these batteries. This is the one and only Goldbat I've ever used.

Link to the post on my Capra thread: Jato The GOAT

I love the HobbyKing Battery Finder because you can filter the batteries by all types of info including the physical side of the battery. Battery Finder is here: LiPo

 

[Reezo]

Isn't Tattu part of Gens Ace? I've always had great luck with Gens Ace until they priced themselves out of the cheap market. Now I go to HobbyKing for most of my batteries.

On my Capra thread I am running Goldbat 3S 1500mAh LiPos. I ran my Capra once, years ago, so I can't give any input into long-term durability of these batteries. This is the one and only Goldbat I've ever used.

Link to the post on my Capra thread: Jato The GOAT

I love the HobbyKing Battery Finder because you can filter the batteries by all types of info including the physical side of the battery. Battery Finder is here: LiPo

Thanks, Jato! Tattu is part of Gens Ace, and (I guess this might mean nothing, but...) there are tons, tons of people in RC who swear by their quality. But whenever I've looked hard enough, LiPo batteries are basically something that you will find 50% pro, 50% con user-base, all time, no matter which brand/size/year they belong to.

Still, once you field them, there are better ones and worse ones, but it seems that judging is based on what works for you. I would not be surprised if they had different batches for different international markets.

Anyway, these have been working fine but they are not a straight-up fit into the Capra. I want to run 4S so I think I can maybe, maybe find something along the 1500 mAh that might fit, or I have to go down to almost 1000 mAh, and maybe get the equivalent of 4 just for that car I'll have better weight performance, but worse voltage sag and the alike.

I'll see, thanks for the links!

 

[JatoTheRipper]

Thanks, Jato! Tattu is part of Gens Ace, and (I guess this might mean nothing, but...) there are tons, tons of people in RC who swear by their quality. But whenever I've looked hard enough, LiPo batteries are basically something that you will find 50% pro, 50% con user-base, all time, no matter which brand/size/year they belong to.

Still, once you field them, there are better ones and worse ones, but it seems that judging is based on what works for you. I would not be surprised if they had different batches for different international markets.

Anyway, these have been working fine but they are not a straight-up fit into the Capra. I want to run 4S so I think I can maybe, maybe find something along the 1500 mAh that might fit, or I have to go down to almost 1000 mAh, and maybe get the equivalent of 4 just for that car I'll have better weight performance, but worse voltage sag and the alike.

I'll see, thanks for the links!

LiPos are difficult to manufacture consistently. So yes, I agree that any company can have a bad batch. The best of companies weed those batteries out before they ship them though. How old is the battery in question?

Sorry, I originally missed the part about 4S. The batteries I recommended were 3S.

 

[89Industries]

I generally run the 3700mAh Helios 3s shorty packs in my Capra (and all my other vehicles mostly).

Helios RC 3S 11.1V 3700mAh 45C Shorty LiPo Battery - XT60

All the latest Radio Control Cars, Trucks, Bashers, Vintage, Rock Crawlers, Scalers, Semi Trucks, Drag Racers, Boats, Planes! Your one stop R/C shop in Ukiah, CA!

www.rpphobby.com

It is as big as will fit in the stock battery compartment. I know you are looking for 4s but this should give you maximum dimensions for a battery that will fit.

I've had really good luck with Helios RC batteries but I don't have much to compare them to. Started with them a few years back and have been happy. Not sure if they're available easily in Europe or not.

My capra is just a very capable trail vehicle since I don't do competitions. I get probably about 3-4 miles or about 2-3 hours of trailing on the 3700mah 3s battery. Also got a 1500mah version that I used for the first time yesterday and got almost 1-1.5 hours, maybe almost 2 miles of trail before hitting the lvc. But I also just switched from a brushed hw1080 set up to a HH revolver and cmv3 brushless, so I'm not sure if the comparison between batteries means much. Also, the Helios batteries get better after about 4 or 5 charges and uses.

There's also a GensAce 3600mAh 3s battery this same size so they may also have some 4s batteries to fit.

 

[Reezo]

LiPos are difficult to manufacture consistently. So yes, I agree that any company can have a bad batch. The best of companies weed those batteries out before they ship them though. How old is the battery in question? Sorry, I originally missed the part about 4S. The batteries I recommended were 3S.

That's right, the way LiPos "are born" is not to be underestimated. Those batteries are brand new, I haven't marked one of the two in the pair but I am pretty sure it's only one that - for the second time (I might have done 3-4 full charges on them, no more) - reaches 100% of the storage load (= 3.80 V) and then when I come back to the charger, I notice all the cells are sitting at 2.8 V. I immediately charged it back to 3.80 V (meaning I ran another Storage task) and they sit reliably at 3.80 V. So going DOWN, the issue happened, going UP, so far it hasn't.

Both packs seem to perform normally for what I expected, at least not with differences after this weird behavior.

I generally run the 3700mAh Helios 3s shorty packs in my Capra (and all my other vehicles mostly).
It is as big as will fit in the stock battery compartment. I know you are looking for 4s but this should give you maximum dimensions for a battery that will fit.

I've had really good luck with Helios RC batteries but I don't have much to compare them to. Started with them a few years back and have been happy. Not sure if they're available easily in Europe or not.

My capra is just a very capable trail vehicle since I don't do competitions. I get probably about 3-4 miles or about 2-3 hours of trailing on the 3700mah 3s battery. Also got a 1500mah version that I used for the first time yesterday and got almost 1-1.5 hours, maybe almost 2 miles of trail before hitting the lvc. But I also just switched from a brushed hw1080 set up to a HH revolver and cmv3 brushless, so I'm not sure if the comparison between batteries means much. Also, the Helios batteries get better after about 4 or 5 charges and uses.

There's also a GensAce 3600mAh 3s battery this same size so they may also have some 4s batteries to fit.

Thanks for the recommendation! I'll look into them, this will give me a good sizing approach to know my max dimensions.

In case anyone is looking for them, the batteries are:

93mm x 43mm x 25mm

and were reported as tight a fit as it gets, on the 1/10 Axial Capra.

I keep a pair of Tattu 4S 850 mAh which run great on comp crawlers (and the Capra, when comp crawling), but I was more obsessed about size (=running a small pack to avoid running into weight distribution issues) last year... since then I noticed that 1) rock racers tend to voltage sag a lot on small packs and 2) big packs are not too bad on trail trucks. I've seen a lot of the G6 guys I know running big packs and the advantages of a bigger mAh pool is to me better than the weight disadvantage (sometimes I am thinking they bias thing better for the added weight, as the tires bite on the terrain of a typical trail run more than with a small pack ... I guess I like my trail trucks to be tanks ).

 

[JatoTheRipper]

That's right, the way LiPos "are born" is not to be underestimated. Those batteries are brand new, I haven't marked one of the two in the pair but I am pretty sure it's only one that - for the second time (I might have done 3-4 full charges on them, no more) - reaches 100% of the storage load (= 3.80 V) and then when I come back to the charger, I notice all the cells are sitting at 2.8 V. I immediately charged it back to 3.80 V (meaning I ran another Storage task) and they sit reliably at 3.80 V. So going DOWN, the issue happened, going UP, so far it hasn't.

Both packs seem to perform normally for what I expected, at least not with differences after this weird behavior.

Have you tried contacting Tattu for a warranty claim? Not sure if they even warrantee batteries.

 

[Reezo]

Have you tried contacting Tattu for a warranty claim? Not sure if they even warrantee batteries.

I might do that. I had them as a gift from a friend when I didn't have enough batteries, I know for sure he never used them but kept them well, because they did not fit his project but he had gone past the return window...

 

[cul8tr]

Helios 3s 1500 45c keep 3-4 with me all the time. Great battery but they are showing their age after 3 yrs.
I've had Ovonic before and I just ordered 4 3s 2200 35c almost the exact size as the Helios.
I have 2 Spektrum smart 1300 3s so far so good but in the past I've had a few that were not up to snuff and wouldn't hold charge.
Smart system is cool but sucks as it is dedicated to their charger.
Don't throw away the tiny charger that comes with some rtr's. If you have a low cell it will bring the battery up so you can use your normal charger.
Capra I traded it but I kept the batteries and use them in my Gatekeeper. SMC #40357 3s 4000 50c.
My SCX6's I don't get to race anymore due to work so my 4s race batteries are used in them. A friend asked why mine was faster than his. I just looked at him and said 4s.
I picked up some Predator batteries a few yrs back and they were outstanding. I went back to that hobby shop and my bro and I bought what they had left. They are still going strong.
Gens Ace I've ran since their beginning but they priced their selves out of the picture for me.

 

[Reezo]

Helios 3s 1500 45c keep 3-4 with me all the time. Great battery but they are showing their age after 3 yrs.
I've had Ovonic before and I just ordered 4 3s 2200 35c almost the exact size as the Helios.
I have 2 Spektrum smart 1300 3s so far so good but in the past I've had a few that were not up to snuff and wouldn't hold charge.
Smart system is cool but sucks as it is dedicated to their charger.
Don't throw away the tiny charger that comes with some rtr's. If you have a low cell it will bring the battery up so you can use your normal charger.
Capra I traded it but I kept the batteries and use them in my Gatekeeper. SMC #40357 3s 4000 50c.
My SCX6's I don't get to race anymore due to work so my 4s race batteries are used in them. A friend asked why mine was faster than his. I just looked at him and said 4s.
I picked up some Predator batteries a few yrs back and they were outstanding. I went back to that hobby shop and my bro and I bought what they had left. They are still going strong.
Gens Ace I've ran since their beginning but they priced their selves out of the picture for me.

Thank you for the overview and tips! It's always good to have some broader view as some brands are hard to find in some countries. I didn't know about Helios nor Predator, I'll keep an eye out.

I've had Ovonic but they didn't deliver as expected, lower chargespan, low punch and weird "that was too quick" run times for some situations under motor load (rock crawling with mild binds, bumping over obstacles or simply "work that motor" situations that are nothing extreme but just not as smooth as open trail cruising).