2s-7-4v-350-mah-gens-ace-30c-lipo-battery

The 2S 7.4V 350 mAh Gens Ace 30C LiPo batteries are intended for use mostly in aircraft RC models such as helicopters and planes. These compact LiPo batteries have a pretty high discharge and charge ratings that we need to confirm in our tests. What is important to note is that the maximum discharge rates mentioned in the specifications are for quite high Amps and the small cables and connectors of the battery may not be able to handle them well.

Official Battery Specifications:

– Capacity: 350mAh
– Voltage: 7.4V
– Max Continuous Discharge: 30C (10.5A)
– Max Burst Discharge: 60C (21A)
– Weight: 25g
– Dimensions: 54,2×30,2×7,8 mm
– Balance Plug: JST-PHR
– Discharge Plug: n/a
– Charge Rate: 1-3C Recommended, 5C Max


2s-7-4v-350-mah-gens-ace-30c-lipo-battery-capacity

Starting the tests with a 1C discharge rate (0.35A) for the 2S 7.4V 350 mAh Gens Ace 30C LiPo battery we’ve managed to get 381 mAh as a maximum capacity, a value that is about 9% higher than the official rating of the battery, so definitely a good thing here. Furthermore up to 25C constant current discharge rate the battery still manages to provide 363 mAh, still more than the rated capacity, though at that rate we’ve measured the battery ending up discharged with a temperature of 68 degrees Celsius or a bit high than the 60 degrees safe zone. The more serious problem however became apparent with the 30C constant current discharge rate test where 10.5 Amps need to pass through the small cables of the battery and this makes them very hot – up to 100 degrees and that is dangerous as they or the connector can melt and short the battery!

The performance of the 2S 7.4V 350 mAh Gens Ace 30C LiPo Battery in our tests:

– 381 mAh at 0.35A load (1C)
– 378 mAh at 1.75A load (5C)
– 376 mAh at 3.50A load (10C)
– 375 mAh at 5.25A load (15C)
– 370 mAh at 7.00A load (20C)
– 363 mAh at 8.75A load (25C)
– 287 mAh at 10.5A load (30C)

While the 2S 7.4V 350 mAh Gens Ace 30C LiPo batteries are capable of handling a constant discharge rate of up to 30C as their specifications say the battery cables used are not designed to properly handle the 30C constant discharge rate!

2s-7-4v-800-mah-gens-ace-20c-lipo-battery

The 2S 7.4V 800 mAh Gens Ace 20C LiPo batteries are intended for use in various RC models such as helicopters and planes. These compact LiPo batteries have a pretty high discharge and charge ratings that we need to confirm in our tests. What is important to note is that the maximum discharge rates mentioned in the specifications are for quite high Amps and the small cables and connectors of the battery may not be able to handle them well.

Official Battery Specifications:

– Capacity: 800mAh
– Voltage: 7.4V
– Max Continuous Discharge: 20C (16A)
– Max Burst Discharge: 40C (32A)
– Weight: 50g
– Dimensions: 56.37×30.74×18.76 mm
– Balance Plug: JST-XH
– Discharge Plug: JST
– Charge Rate: 1-3C Recommended, 5C Max


2s-7-4v-800-mah-gens-ace-20c-lipo-battery-capacity

Starting the tests with a 1C discharge rate (0.8A) for the 2S 7.4V 800 mAh Gens Ace 20C LiPo battery we’ve managed to get 793 mAh as a maximum capacity which is a bit short from the rated capacity of 800 mAh though at less than 1% it is not a problem. Going for higher discharge rate the battery still manages to offer very good capacity even at 20C it handles pretty well with 749 mAh useable capacity. The problem however is that at 20C constant current discharge rate the cables of the battery get way too hot, we’ve measured 98 degrees Celsius and that is way too high. The cables getting hot are just an indication that the current passing through them is more than what they can safely handle.

The performance of the 2S 7.4V 800 mAh Gens Ace 20C LiPo Battery in our tests:

– 793 mAh at 0.8A load (1C)
– 784 mAh at 4.0A load (5C)
– 774 mAh at 8.0A load (10C)
– 765 mAh at 12A load (15C)
– 749 mAh at 16A load (20C)

While the 2S 7.4V 800 mAh Gens Ace 20C LiPo batteries are capable of handling a constant discharge rate of 20C as their specifications say the battery cables used are not desgned to properly handle the 20C constant discharge rate!

9v-expiring-carbon-zinc-batteries

One thing you should be very careful about is the expiration date of Carbon-Zinc and Alkaline batteries (primary batteries) as the closer the battery is to the end of its life cycle the less capacity it will be able to provide. More often than not when you pick a single use battery from a store you expect it to have a lot of time left before the expiration date is reached, so you don’t check the date printed on the battery, however this can be a mistake. Although Carbon-Zinc and Alkaline batteries usually have a low self discharge rate and long shelf life they are not going to perform so well when they are close to their expiration date as they would when they are new (usually 3-5 years after they were manufactured). The problem is more serious for Carbon-Zinc batteries that usually have less shelf life and offer lower capacity than Alkaline batteries, so you should be even more careful with these. And while some battery manufacturers may put a few months as an extra over the expiration date others may not, and there are also some additional factors that may influence the battery life such as the storage conditions and such. So in general you should check the battery expiration date when you buy primary batteries and if there are just a few months left you should not get them even if you do plan on using them immediately.


9v-expiring-carbon-zinc-batteries-capacity

We’ve decided to test some Carbon-Zinc batteries that are either close to their expiration date or have already passed it, so after a bit of looking around we managed to actually buy such batteries – yes you can sometimes find expiring or even expired batteries still being sold in stores and these are usually Carbon-Zinc ones and not Alkaline. We got a 9V GP Powercell Carbon Zinc battery that expires in September 2013 (next month) and a 9V Maxell Zinc battery that has already expired in June and put them to a test using our test scenario for 9V batteries. This includes a constant discharge rate of 0.05 Ampers (50 miliamps) in order to measure what is the useable capacity we can get from these two batteries and the results we’ve got were quite surprising for us. The soon to expire 9V GP battery ended up hitting the cutoff voltage with just 38 mAh useable capacity and the already expired 2 months ago 9V Maxell battery still had 98 mAh. So even at the end of their life primary (single use) batteries may still be useable, however their useable capacity will be significantly less than what they are able to provide while new!

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