Battery advice.

Spils77 · #1 10-12-2014

Hi all,

It appears battery technology has moved on since I first used to race rc cars 20years ago using SCRC saddle/stick packs. From what I can see everyone prefers using Lipo batteries, but how safe are they? I have read so much about these batteries starting/causing fires. Now I know battery maintenance is down to common sense at the end of the day but some advise on where and how to store these batteries would be appreciated. Can these packs be stored in a garage with a lot of temperature changes sometimes hitting minus figures or do they have to be kept at room temp and if so where is the best place to keep them?

This topic may have already been covered but I am a new member so go easy on me

szymanski2oo1 · #2 10-12-2014

well this is what i do based on my own research .... please feel free anyone out there to correct me...

1. buy a good quality branded lipo from a model shop ( if your planning to race at brca meetings make sure its on their list of approved battery's )

2. buy a good quality branded charger from a model shop and always balance charge your batterys ( dont risk buying a random chinese copy of something )

3. make sure all your cables are soldered properly with good connections....

4 clearly label your plus and minus cables in your buggy with colour coded cables or at least heat shrink, or shorten one of the cables so that it can only meet the correct terminal of the battery ( reduces risk of shorting out a battery and esc..... ive stupidly damaged a speedo and a lipo by mixing cables! )

5 always charge your lipos in a battery sack ( special fire resistant bag )

6 when charging your lipo dont leave it unattended.

7 dont leave your lipo batterys fully charged for a long period of time put them in to storage charge level.

8 i use an old ammo tin to keep the batterys in .... and i keep them in the garage its cold in there epecially now but im not sure whaere else to leave them as i dont want to leave them in the house.

from all i have read up on if you follow the above you should be safe as houses....its all precautionary stuff... ive been running for a year now and touch wood no problems...

anyone else out there please correct me if ive missed anything

Spils77 · #3 10-12-2014

Thank you szymanski2001 for your detailed reply. I am definitely thinking along the same lines with regards to keeping these batteries in the garage. I like the idea of putting them in a fire resistant bag and then putting them in an ammo container. Do you have to vent the container at all to prevent any build up of gases?
I take it the batteries can handle the cold ok, I know our garage can get into the minus figures when we have a harsh winter.

szymanski2oo1 · #4 10-12-2014

ah well yes i think so .... i just leave the lid not 1000% fastened ... it wont blow off but its not air tight ... been meaning to drill some proper vent holes but not got round to it!

JCJC · #5 11-12-2014

Not sure about the temperature thing, all batteries seem to (like me) have a dislike to freezing temperature. Mostly lipo's are easier and quite stable.

20 years ago was that nicad ? the last of the nimh cells were a bit temperamental, some problems, lipo's soon replaced the old cells for many reasons, cost, ease of use, weight, power, they look cooler.

As above - brca approved (hard case etc), pucker lipo charger, charge at no more than 1C (5000Ah @ 5A max, 3000Ah @ 3A max) in a lipo sack, charge is a lot less than an hour because you are topping up every time. One battery may be all you need, top up between races (you may like a spare), never let the battery voltage drop below 6 or 6 and a bit volts, may damage your battery and charger may refuse to charge it. (1C, yes there are new numbers and other questions)

Modern esc's have voltage cutoff's, car may stop if voltage is low.

Mostly lipo's are easypeesy, even with old cells bad connections caused problems. There will be a few additions to the approved list for 2005 (Feb/March?), batteries on 2004 list remain. Secondhand can be a good buy.

Yea, you can be stupid with them, film it and stick it on youtube etc, you may have lipo in you smart phone in your pocket, in your laptop, radio, dyson, power tools even your transmitter............

You will grow to love them.

Edit: towards the end of nimh era, 2007, http://www.oople.com/forums/showthread.php?t=6362

HOTSHOT III · #6 11-12-2014

Quote:

Originally Posted by Spils77

Thank you szymanski2001 for your detailed reply. I am definitely thinking along the same lines with regards to keeping these batteries in the garage. I like the idea of putting them in a fire resistant bag and then putting them in an ammo container. Do you have to vent the container at all to prevent any build up of gases?
I take it the batteries can handle the cold ok, I know our garage can get into the minus figures when we have a harsh winter.

You need to be careful with LiPos in the cold weather; a LiPo cell which was fully charged at room temperature can exceed the critical 4.2v when exposed to sub-zero temperatures. I've always stored mine indoors for 3 years (in an ammo box as someone else said) and never had any problems.

I've asked several times for the article below to be included as a sticky in this section as for anyone new to LiPo batteries, it answers every question you might need to know. When I started racing in 2011 I knew nothing about LiPo, I read the article a few times and basically felt like I was ready to start:

http://www.rchelicopterfun.com/rc-lipo-batteries.html

Hope this helps

Spils77 · #7 11-12-2014

Thank you for the comments JCJC & Hotshot III, Both attached articles have made good reading and definitely given me a good insight into these batteries.
From what I have heard and read it just seems that as long as you don't misuse the batteries and apply a bit of common sense then they should be fine.
I still feel a little bit apprehensive about having them in the house, so I think until I am more confident using them, the garage for me is the best option.
I guess for race meetings (practice, three heats + final) then one pack should be sufficient. What rating or battery capacity would be the norm for a race day?
Also would the HPI reactor 500 charger be ok to look after charging, balancing and storage of the batteries?

And thank you guys for your help with this.

JCJC · #8 11-12-2014

Funny how a lot of chargers look like my old trusted BC6, nice to have mains & 12 volt input, 5 Amp max output is good enough, a selection of cables, seems to cover most options.

Batteries may need to fit whatever you are racing, you will understand stick & saddle, there may be other options and may be possible to run saddle as stick in the long slot, you need to adjust to battery connectors & balance connectors as well.

Perhaps you should visit a local club/meeting and look around, drivers have time to chat between heats and most are friendly, not practice, heats & three finals then ?

HOTSHOT III · #9 11-12-2014

Quote:

Originally Posted by Spils77

Thank you for the comments JCJC & Hotshot III, Both attached articles have made good reading and definitely given me a good insight into these batteries.
From what I have heard and read it just seems that as long as you don't misuse the batteries and apply a bit of common sense then they should be fine.
I still feel a little bit apprehensive about having them in the house, so I think until I am more confident using them, the garage for me is the best option.
I guess for race meetings (practice, three heats + final) then one pack should be sufficient. What rating or battery capacity would be the norm for a race day?
Also would the HPI reactor 500 charger be ok to look after charging, balancing and storage of the batteries?

And thank you guys for your help with this.

Reactor 500 charger looks good but a bit expensive, I have 3 of these which again i've had for 3 years and they've been very reliable:

http://www.modelsport.co.uk/core-rc-...roducts/365880

For racing 1/10th buggies i'd say anything 2S (i.e 7.4v) over 4000mah and 40-50C should do the business.

Personally i'd get 2 batteries to start with if possible, only because it's good practice to let them cool down a little rather than putting them straight back on charge after a race.

As for keeping them in the garage this shouldn't be a problem as long as they're at or near storage voltage but like I said, when fully charged they should be stored at room temperature, it's overcharging (i.e exceeding 4.2v per cell) which makes them catch fire so when fully charged like the night before you go racing they're actually safer if kept indoors IMO.

Spils77 · #10 11-12-2014

Thanks for all the advice, The core charger does seem to do everything the HPI charger does at half the price so that will save some money which I can put towards a second battery.
Will take on board what JCJC said and pop down to my local club and have a chat with some of the people there. I think it would be good to see what set up people are using motors/esc etc.

JonyNitro · #11 12-12-2014

Charger I like this one, very good reviews

http://www.modelsport.co.uk/overland...roducts/379060