SDS CDI vs Pmag

[rv6ejguy]

Originally Posted by flyboykelly

7 and 9 cylinder!?!?

Our systems are all waste spark so hard to do on odd numbers of cylinders plus only a tiny market for Experimental radials so there would be a very long return on investment to develop new hardware and software.

[rv6ejguy]

We're into the meat of the backup battery switching and OV protection circuits now. Just a bit of a poll for backup battery capacity/ weight- 30-40 mins and 1.2 pounds or 70-80 minutes and 2.1 pounds?

[gasman]

Originally Posted by rv6ejguy

We're into the meat of the backup battery switching and OV protection circuits now. Just a bit of a poll for backup battery capacity/ weight- 30-40 mins and 1.2 pounds or 70-80 minutes and 2.1 pounds?

I would go for the 70-80 minutes and 2.1 pounds.

[qtrmiledan]

Second vote for 2.1 lbs and longer time.

[Chkaharyer99]

I choose the second option. 70-80 minutes and 2.1 pounds. What battery chemistry? SLA, LIPO, other?

[rv6ejguy]

Originally Posted by Chkaharyer99

I choose the second option. 70-80 minutes and 2.1 pounds. What battery chemistry? SLA, LIPO, other?

Lead acid AGM.

[DanH]

14 ounces for an extra 40 minutes? I'd take that.

[RogerG]

Originally Posted by gasman

I have had one of these Powersonic PS 5ah on my bench for over 5 years and has maintained an 90% charge for a 12 month standby period. It gets charged once a year.

Ross,

A quick browse on EBay I see solar power controllers that support AGM, and many various sizes, and specs for MC (Mono Crystaline) flexabile solar panels. I'm not an expert with this technology but interested if this might be a light weight alternative for keeping an AGM battery fresh. The MC panels look like they could be incorporated into sun visors, or integrated some way fairly easy.

[rv6ejguy]

Originally Posted by RogerG

Ross,

A quick browse on EBay I see solar power controllers that support AGM, and many various sizes, and specs for MC (Mono Crystaline) flexabile solar panels. I'm not an expert with this technology but interested if this might be a light weight alternative for keeping an AGM battery fresh. The MC panels look like they could be incorporated into sun visors, or integrated some way fairly easy.

Right now we are looking to recharge the backup battery via ship's power with an isolation circuit for low and over voltage. Seems few people are keen to worry about that staying charged by external means even though these batteries retain over 90% charge after 2 months at 20C ambient. All options are on the table at this time though. Appreciate the input from all here.

[Carl Froehlich]

Originally Posted by rv6ejguy

We're into the meat of the backup battery switching and OV protection circuits now. Just a bit of a poll for backup battery capacity/ weight- 30-40 mins and 1.2 pounds or 70-80 minutes and 2.1 pounds?

One approach is to look at aircraft power requirements as a system, not as individually components. This way you can find more efficient and effective ways to achieve design objectives instead of the brute force approach of having multiple backup batteries; one or two for the igntions, one for the left EFIS, one for their right EFIS, etc.

Carl