sundevil67

I charged 2 pairs of 4S LiPo batteries last night, planning on running them today. It turns out I may not wind up running my truck until Sunday, which would mean they will have been sitting for 5 days between charging & running. Is it really necessary to initiate a 'storage' cycle now, and charge them the night before? Is the downside of just running them Sunday a little decreased performance, none at all, or a real impact (minor or major) to the longevity of the packs?

Thank you!

DirkW

iTrader: (1)

LiPos should never be stored at full charge over longer periods of time (measured in hours, not days, weeks or month). Personally I put them into storage mode whenever I'm done with them for the day, and I would never have them sitting around fully charged over night (let alone 5 days). Doing so can indeed really harm your batteries (they are more likely to puff or develop other problems that way).

bentouttashape

iTrader: (5)

If you want a second opinion, my advice is to listen to DirkW.

sundevil67

Thanks so much for the fast advice! I'll taker 'er out for a test run today & recharge for the event Sunday.

sundevil67

One more question ... I'm still getting used to this new Spektrum charger. In some ways it's simpler than my old Venom unit, but the software can be a little quirky at times. It does this sometimes when I use 'storage' mode..it'll just keep on running until I decide to shut it down manually instead of completing the storage/balance routine. It's been running several hours now (picture of the display below), and I'm not sure it'll ever actually finish. Is the software crashing again or is this an indication of a potential problem with either the charger or the batteries?

Cromulent

iTrader: (8)

It looks like it is discharging at 0.3A, which will take quite a while. Is the capacity (mAh) changing? If so, everything seems fine, cells are staying balanced and it's doing it's job, it just may not be set up correctly. If the capacity isn't changing, then unplug everything and try it again. I would discharge/storage charge at the max allowable amperage the charger offers. Most chargers like that have very limited power dissipation (wattage), so it is a slow process. Many folks use the ISDT 6A discharger (cheap, loud, slow but faster than built in discharging most of the time), or a SkyRC BD250 (fast, quiet, but a bit more money) for putting batteries into storage.

mossman2

iTrader: (5)

So if you don’t want to leave these batteries charged for more than a few hours, how do you guys prep for a race? We race on Friday nights and I can’t get home and get batteries charged before going. I have to charge the night before.

I did order the ISDT discharged based on this thread, but I still am struggling to figure out how to pull this off. We are running two truggies on 4S, we go through 5 packs each every night. Are you charging throughout the race day? Our club races are small, so we have maybe an hour between races.

I do use the charging board l, so I can charge 4-6 at a time, that reduces time quite a bit.

Xrayray

It's usually best to charge between races. I run 2 classes on one Gens Ace lipo. 6 runs plus practice runs. The battery resistance goes down and the car has more punch.
You will have to charge at least 2c rate, or twice the amps on your lipo label. Do so at your own risk, as lipo manufacturers usually recommend 1c charge rate.
From storage, any lipo will charge in about 22-25 mins at 2c charging. Imo 2c still has a low risk to lipo longevity.

DirkW

iTrader: (1)

99% of the time I only charge at the track, right before I drive the car (1% I charge a pack or two at home, right before I leave for the track). 95% I put my batteries into storage mode before I leave the track as well (5% I do it after I get home, same afternoon/evening).

sosidge

This is an ISDT charger under the skin, it keeps going after the storage is complete and it it spots a imbalance in voltage it will do a small correction. Nothing to worry about. Although 4.08V as a storage voltage is unusual, normally you would be at 3.8/3.9-ish.

DirkW

iTrader: (1)

Unless of course it's really set to use only 0.3A discharge current and was started at 4.20V... then of course it's going to take hours. If so, you should definitely change those settings.

billdelong

iTrader: (33)

There is no hard set rule, but if you want to extend the life of your batteries, then you want to minimize the amount of time they are not in storage mode, more info here:
https://batteryuniversity.com/articl...ased-batteries

It's also important to note that you want to charge your batteries at the same ambient temp they will be used. For example TheJANG from URC had reported an incident where he charged several brand new packs inside his home at 72°F then placed his batteries in the trunk of his car and drove 2 hours away to the beach. Outside temps were close to 100°F and by the time he arrived at his destination the battery packs had swollen to the point like they were balloons! What happened was the increase in temperature caused the voltage to spike which in turn damaged the batteries. If he had placed the batteries at storage voltage, and waited to charge them after he got to the beach, then his packs would've been perfectly fine, though I would recommend placing the batteries inside the car with cool A/C as temperature also effects the age of batteries as explained in the link I posted above.

Good Luck!

GerryH

iTrader: (26)

The S2100 charger has a discharge rating of 5W, so with a battery at 16.3v discharging at .3a, you're getting 4.89 watts. So it's working as it should. And while you didn't mention your battery capacity, you can see it will take many hours to take a fully charged lipo down to storage voltage. Very common problem with most chargers. They aren't designed for this.

Adding to Bill's comments, I also know some fellow racers that left their discharged lipos in their cars (non-RC) in hot summer only to find them completely puffed up a couple days later. It's not so much the voltage, but the prolonged heat.

You should be fine charging them up the night before as long as your keeping them in a cool location.

gigaplex

iTrader: (2)

A hot trunk can kill lipos fast even if they're at storage voltage.

soulcoma

iTrader: (47)

i cahrge my lipos the night before the race or bash day. if I end up no going or using all of them I put them back to storage. I never let them sit more than a day in charged status. Sometimes you get caught up and forget. But as soon as I remember I thought them into storage.

but as a rule never them in charged state for longer than 24hrs if you can help it. best practice is charge and use. but thats not always an option.