Prodigy batteries review

[a2dcovert]

I have been monitoring the batteries in my Prodigy when they go flat. I am concerned that I am seeing different voltages from the pairs of LiFePO4's. Just now I changed the batteries. One was at 2.44 and the other one was 2.21. They're supposed to cut off at 2.4. This is happening fairly often so I'm going to try to check them and stop using them a little early if possible.

I have some Tenergy RCR123A Li-Iion batteries that I've been using with mixed results. The appear to have a lower C rating than the LiFePO4's even though the LiFePO4's have a rating of 750mAh and the Li-Ion's are rated at 900mAh. The LiFePO's have more punch than the Li-Ions. The Li-Ions power curve seems to start dropping sooner than the LiFePO's. The vapor production starts dropping off noticeably and I usually change them out long before they go flat. Checking the voltage, unloaded, they still have voltages in the 3.3 range.

So, while I prefer to use the LiFePO4's the low voltages concern me that their life span might be shortened by running them too low. The Li-Ions do last longer but the drop in performance makes me swap them out while they still have plenty of charge left. I guess the long term testing will determine how long each group works. Right now the stock batteries have the advantage. More testing to do.

Kevin

 

[BrockJ]

I don't know how many cycles you have on the batts but they take four or five good cycles before they really get to their full capacity. *Sweet Spot*

It's not uncommon for batts to charge or drain at different rates. You can try to match them in pairs and get better performance. Even the lower performing batteries "If paired correctly" will perform better.

Typically li-anything batts have an 80% rule.If you have a digital charger that shows you what you're putting back you shouldn't be draining more than 80% of the total mah.

So if it's a 900mah and you're putting back more than 720 that's too much.

You can also charge at 1c with a digital and peak the batteries to fill them all the way up.

I fly remote helicopters that run 12s / 5500mah batts. Charging & draining becomes very important at $450.00 a pack.

 

[a2dcovert]

The batteries i'm discussing are over 3 weeks old so they have more than 20 cycles on them.

I am trying to match them because they are being used in series. We do not use high tech chargers. All we have for the cylinder batteries are the simple chargers designed to charge them. This is why the cylinder batteries are able to be used. The chargers and protection circuits are supposed to keep them safe.

These batteries have a very low C rating.

Kevin

 

[a2dcovert]

I have been monitoring the batteries in my Prodigy when they go flat. I am concerned that I am seeing different voltages from the pairs of LiFePO4's. Just now I changed the batteries. One was at 2.44 and the other one was 2.21. They're supposed to cut off at 2.4. This is happening fairly often so I'm going to try to check them and stop using them a little early if possible.

I have some Tenergy RCR123A Li-Iion batteries that I've been using with mixed results. The appear to have a lower C rating than the LiFePO4's even though the LiFePO4's have a rating of 750mAh and the Li-Ion's are rated at 900mAh. The LiFePO's have more punch than the Li-Ions. The Li-Ions power curve seems to start dropping sooner than the LiFePO's. The vapor production starts dropping off noticeably and I usually change them out long before they go flat. Checking the voltage, unloaded, they still have voltages in the 3.3 range.

So, while I prefer to use the LiFePO4's the low voltages concern me that their life span might be shortened by running them too low. The Li-Ions do last longer but the drop in performance makes me swap them out while they still have plenty of charge left. I guess the long term testing will determine how long each group works. Right now the stock batteries have the advantage. More testing to do.

Kevin

I have one correction to make. On the Official Tenergy site the specifications for this battery state that:

New Chemical LiFePO4 Li-Ion battery

• Rechargeable LiFePO4 RCR123A 3.0V 750mAhBattery
• Life cycle: 2000 times (Traditional Li-ion: 500 times)
• Never explode or catch fire
• 100% Compatible with Disposable CR123A Batteries
• Working Voltage:3.2V and Peak Voltage: 3.6V
• Charging cut-off voltage: 3.6V
• Discharge cut-off voltage: 2.2V
  • Please never overdischarge battery below 2.2V/cell
  • Charge the this battery with LiFePO4 RCR123A smart charger.
• Capacity: 750 mAh
• Maximum discharging rate:< 550 mA
• Maximum charge current: <550 mA
• Cell's dimension: 17mm Dia. x 34.5mm H.
• Weight: 0.6 oz (18 grams).

This means that these batteries are performing exactly as rated. So my initial review was flawed. I give these batteries 5 stars.

Kevin

 

[bearscreek]

The odd thing I found about these batteries is that the actual package says that they have 1000 charge cycles. (Of course, I'm still not complaining.)

 

[a2dcovert]

That's true, 2000 seems like a stretch but even 1000 is 3 times more than Li-Ions. Guess time will tell.

Kevin