Anybody happen to remember the Advisory Circular or other reference that allowed one to replace a lead-acid battery with a non-TSO’d lead -acid type without Field Approval or STC with the condition that the weight had to be within 1 lb? I seem to remember that in the distant past that was allowed, but I’m having no luck finding it now.

Thx!

Google knows all. I found it on supercub.org, but they copied it from this site in 2011. Batteries are discussed in chapter 10.


https://www.faa.gov/documentLibrary/med ... .13-2B.pdf

Thanks, Dale. Your Google-Fu is stronger than mine. This isn’t quite the way I remember it, here’s the non-TSO reference:

Subject: Acceptable Methods,
Techniques, and Practices – Aircraft
Alterations
Date: 3/3/08
Initiated by: AFS-300
AC No: 43.13-2B


1004. AIRCRAFT STORAGE BATTERY
DESIGN AND INSTALLATION.
a. Lead Acid.
(1) Each aircraft storage battery, whether approved to a Technical Standards Order (TSO) or not, must be designed as required by regulation and installed as prescribed by the manufacturer.

There’s no specific mention of weight, other than to say:

1021. WEIGHT AND BALANCE. After
installation or alteration with the replacement battery
the weight and balance of the aircraft should be
recomputed if:
a. The weight of the replacement battery is
different from that of the original battery.
b. The location of the battery is different from
that of the original battery.

I found AC 23-27 from 5/18/09 which goes mostly how I remembered it:

https://www.cessnaflyer.org/media/kunen ... rcraft.pdf

“ 2. BATTERIES. If one type of series 35 battery (e.g. a Gill 35) is approved as original
equipment or a PMA part, and another type of series 35 battery (e.g. a Concord 35) is PMA
approved for some aircraft models but not your model aircraft, you may install the alternate type
of series 35 battery and document the installation with only a logbook entry. This applies to all
series 35 batteries. This philosophy also applies to other series, such as series 25 batteries.
However, this part substitution is permissible only as long as the batteries are the same weight,
within plus or minus one pound, and have such similar physical characteristics as to enable the
use of the same securing or attaching devices, mechanisms, or containers.

Approval: This is a minor alteration and you may document it by a logbook entry. The logbook
entry must reference the original and replacement manufacturer's identification or the
performance specifications of the original and replacement battery.”

In my case, I’m interested in this because my C180 had an STC’d Dan’s Aircraft firewall battery box installed with an Odyssey SBS J-16 Aircraft Battery, which is a FAA-PMA 14.8 lb 15 AH 220 CCA @ 0˚C AGM battery, now costing in the region of $300. There are more modern and less expensive AGM batteries from other manufactures with higher AH & CCA which would fit in the battery box and connect the same. Unfortunately, whereas AC 43.13-2B implies non-TSO is OK, AC 23-27 wants it to be PMA’d for at least some aircraft. Looks I’m stuck buying weak expensive batteries unless I want to go full-Alice and try for field approval.

jrc111 wrote:....... my C180 had an STC’d Dan’s Aircraft firewall battery box installed with an Odyssey SBS J-16 Aircraft Battery, which is a FAA-PMA 14.8 lb 15 AH 220 CCA @ 0˚C AGM battery, now costing in the region of $300. There are more modern and less expensive AGM batteries from other manufactures with higher AH & CCA which would fit in the battery box and connect the same. .....

Can you share info on those batteries?

Here’s a couple:

https://amzn.to/3ElXSQw
https://amzn.to/4jA4YzH

Basically, bolt-in, same or less size, weight within 1 lb, higher CCA/AH.

jrc111 wrote:https://amzn.to/3ElXSQw
.

Energizer TX20HL: 18AH & 310 CCA. $98 from Amazon
vs
Odyssey SBS-J16: 15AH & 220 CCA. $190 from Battery Mart ($279 from Spruce)

Curious on battery life of the cheaper replacements. How do they handle heat in the cowling, vibration, etc...

My first SBS-J16 Lasted me 5 years, it was installed 2 years prior to me buying the plane. It still worked, but when cold out it could barely turn over the 520. In the 2 years prior to me buying it the plane sat for extended periods.

A guy I know installed one of these Energizer batteries in his 180, replacing a 5 year old Odyssey.
Fit nicely into his Burl's firewall battery tray, cranks over noticeably better than the Odyssey.
Paperwork to follow....