serial parallel designations

[srvnet]

I am totally new to this lipo stuff and I don't want to have any problems with my new heli. My question is some of the batts say 3s on them some say 3s1p. I think I know what that means but will both bats work in a trex se. Please help me become informed so I don't wreck something. Also where's the best information located on care for these batteries? Thanks, Rudy

[kamtsa]

I am totally new to this lipo stuff and I don't want to have any problems with my new heli. My question is some of the batts say 3s on them some say 3s1p. I think I know what that means but will both bats work in a trex se. Please help me become informed so I don't wreck something. Also where's the best information located on care for these batteries? Thanks, Rudy

3S is often used as a short for 3S1P so the two have probably the same configuration. LIPO Batteries also differer in their capacity (mah units) and discharge rate (C units). Most have a specified max charge rate of 1C unless specified otherwise. They also differ in qualities, some brands (typically the more expensive ones) have better reputation than others.

I presume that you have a LIPO charger/balancer. This is a must. My personal preference is FMA Direct Cellpro 4S.

As for caring for your batteries, I would start with the instructions that came with the batteries and with the charger.

LIPO batteries can catch fire and burn your house or car so be careful.

Kam

[srvnet]

3S is often used as a short for 3S1P so the two have probably the same configuration. LIPO Batteries also differer in their capacity (mah units) and discharge rate (C units). Most have a specified max charge rate of 1C unless specified otherwise. They also differ in qualities, some brands (typically the more expensive ones) have better reputation than others.

I presume that you have a LIPO charger/balancer. This is a must. My personal preference is FMA Direct Cellpro 4S.

As for caring for your batteries, I would start with the instructions that came with the batteries and with the charger.

LIPO batteries can catch fire and burn your house or car so be careful.

Kam



Thanks for the reply Kam, I picked up most of this stuff off of Ebay so some of the instructions are missing. I'm getting most of my new knowledge right here. I got the heli (trex 450 se), reciever (br6000), a couple of the align batteries a charger (hobbico mkii), a balancer(3s dualsky models) and a bunch of extra parts. I don't know if this is a good charger and balancer or not. Also I see that cheeper batteries are probably not a good idea. I really appreciate the help. If you think of any place that has this knowledge all compiled into one bunch that would be great. I need something like a lipos for idiots book.

[BarracudaHockey]

Lets assume for the following discussion 3.7 volt 1000 mah lipo batteries.

In series batteries you add voltage. So a 3s pack would end up being an 11.1v 1000 mah battery.

In parallel you add capacity so a 3p pack would be a 3.7v 3000 mah battery.

As they said, anything that just shows the S designation, like 3s is assumed to be 1p.

Now if you were looking at a 3s2p pack you add the voltages of the series cells, in this case 11.1v, and the capacity of the parallel packs, and you would come up with 2000mah
so a 3s2p pack is two sets of 3s cells wired in parallel.

Let me know if that doesn't make sense.

[kamtsa]

Thanks for the reply Kam, I picked up most of this stuff off of Ebay so some of the instructions are missing. I'm getting most of my new knowledge right here. I got the heli (trex 450 se), reciever (br6000), a couple of the align batteries a charger (hobbico mkii), a balancer(3s dualsky models) and a bunch of extra parts. I don't know if this is a good charger and balancer or not. Also I see that cheeper batteries are probably not a good idea. I really appreciate the help. If you think of any place that has this knowledge all compiled into one bunch that would be great. I need something like a lipos for idiots book.

Hi srvnet,

I am not familiar with the Hobbico MKII charger but if I understand it's spec correctly, it can charge LIPO's up to 1A ("0.2A (200mA) to 2.0A of adjustable, linear charge current (1A max. for Li-Ion/Li-Po)."). If so, your charging of a 2100mah battery will take twice as normal. Make sure to set it correctly to the battery type (LIPO) and the number of cells (3 in case of 3S, 3S1P or even 3S2P).

If you plan to buy in the future another charger, I recommand to take a look at the Cellpro 4S. It can charge up to 4A and it is considered to be relatively safe (it charges through the balancer connector so you cannot be wrong about the number of cells). It also has built in balancer, two line LCD display and is priced very reasonably (I have two of those).

The Align batteries have bad reputation in general (they tend to puff). I never had one so it is not based on personal experience. I am using Thunder Power (about $75 each) and Cell Prorevolution (about $48 each) and get good results from both (I am a mild flier, no heavy duty 3D yet). There are other

Regarding charging LIPO, people came with all kind of ideas how to make it safer. See for example Battery Bank, Lipo Sack or even simple ammu boxes with nylon sand bags that cover the battery automatically in case of fire. I am using LipoSack.

You can find some LIPO related links here http://www.fmadirect.com/tech_data/index.htm (look for example at LIPO Handbook Section 3). I am sure there are many others on the Net. Also, you want to search You Tube for: LIPO fire (but don't try it at home ;-))

Hope this helps. Its probably just the tip of the iceberg but you will learn as you go.

Kam