Circuit breaker popping when battery is low

Any DA40 related topics

Moderators: Rick, Lance Murray

User avatar
Steve
5 Diamonds Member
5 Diamonds Member
Posts: 1953
Joined: Thu Aug 12, 2010 1:23 am
First Name: Steve
Aircraft Type: DA40
Aircraft Registration: N432SC
Airports: 1T7
Has thanked: 81 times
Been thanked: 493 times

Re: Circuit breaker popping when battery is low

Post by Steve »

Rich wrote:This is potentially true, but the first question is what the max charge rate should be.
Found it in the Concorde maintenance manual (Document 5-0171 Rev M, March, 2012):

"NOTE: THE OUTPUT CURRENT OF THE CHARGING EQUIPMENT SHOULD BE SET AS HIGH AS POSSIBLE. RG SERIES BATTERIES CAN ACCEPT CHARGING RATES UP TO 8C1.

(Their bold print)

C1 is the rated capacity in Ah, so for my RG24-11M, 11 ampere hours, and I can charge it at a constant potential with a current of up to 88 amperes. Those with RG24-15M batteries could charge at a current of 120 amperes. Obviously, this capacity is not available in our aircraft, and, I'm not sure is is wise to do on a regular basis, but doesn't seem to be a problem with the battery manufacturer...

Steve
User avatar
Rich
5 Diamonds Member
5 Diamonds Member
Posts: 4592
Joined: Mon Aug 30, 2010 12:40 pm
First Name: Rich
Aircraft Type: DA40
Aircraft Registration: N40XE
Airports: S39 Prineville OR
Has thanked: 145 times
Been thanked: 1180 times

Re: Circuit breaker popping when battery is low

Post by Rich »

Too high a charging VOLTAGE is definitely a problem. At high temperatures ideal charging voltage is lower than when cold. I once had a motorcycle (a '75 Honda Gold Wing) which had a system voltage of almost 15 volts. Riding this bike in a sustained temperature of 85+ degF would cause it to purge water out of the flooded-cell battery at an amazing rate. 3-4 hours of this and the plates would start to become exposed. The bike would actually come to not run over 80MPH and fuel mileage would sink from around 40 MPG to below 30. I'd have to stop, buy some distilled water, and refill.

I wound up building my own voltage regulator to run at about 14.4 volts.

BatteryMinder charges have a temperature sensor to vary with hangar temperature.

The two voltmeters in my DA40 run at 28.3-28.3 volts.
2002 DA40-180: MT, PowerFlow, 530W/430W, KAP140, ext. baggage, 1090 ES out, 2646 MTOW, 40gal., Surefly, Flightstream 210, Orion 600 LED, XeVision, Aspen E5
User avatar
Tim H
4 Diamonds Member
4 Diamonds Member
Posts: 453
Joined: Wed Dec 29, 2010 3:44 pm
First Name: Tim
Aircraft Type: DA40
Aircraft Registration: N233MA
Airports: KMGY
Been thanked: 34 times

Re: Circuit breaker popping when battery is low

Post by Tim H »

Been there, done that!! UGH!!

Flew over to Columbus Indiana (KBAK) for breakfast (excellent food!!). When I returned to the plane after a belly full of pancakes, I discovered I had left the master on....maybe 45 minutes to an hour. The good news was the plane started, but the bad news was the Main Bus and the ESS Bus breakers tripped when the amperage exceeded ~45 AMPs. (I had pushed the RPMs up to 1800+ in a mis-guided effort to charge the battery.)

I went into the FBO and logged into the DAN website and found the solution in this thread. I started the engine, kept the RPMs low enough to keep the amps below ~25, and the breakers did not trip. After 10-15 minutes, the battery was charged and even at higher RPMs the amperage was low enough to keep the breakers from tripping.

Thank you DAN for your help!!
Post Reply