Historically, Columbia-s used to ship with Gill batteries (G230S). They are very light but also pretty low capacity. This was not a problem on any Avidyne planes (where the avionics don't eat as much power) or on 14V planes (different batteries) but became a huge problem on the 24V G1000 planes where batteries started failing left and right. Short scoop: if at all possible, avoid the Gill 24V batteries (G230S) and get Concorde-s instead. There is a mild weight penalty (extra 2lbs per) but the Concorde batteries will actually last.

Approved Batteries




RG12-15 (*)
RG12-15 (*)

As per Cessna :
# The batteries that are approved for the 300/350/400 series aircraft are manufactured by Gill (Teledyne) and Concorde. Both manufacturers determine and publish their respective list prices. For most products made by OEM’s other than Cessna, the Cessna Authorized Service Stations have a number of sources they can buy from. They do not have to buy from Cessna. Therefore, Cessna does not set the list price nor has any control or influence over what price the Cessna Authorized Service Centers sell products such as batteries for. This principle is true for most aftermarket product not produced by Cessna.
  1. The Batteries that are approved by Cessna Type Certificate (TC) are:
    • Gill, G230S, List Price $762.93. There are Service Letters available to enable replacement of these batteries by the Concorde Battery.
    • Concorde, RG24-10, List Price $649.95. Service Letters SL-07-007B is applicable to the LC42/350 models and Service Letter SL-07-005B is applicable to the LC41/400 models.
    • Concorde, RG1215, List Price $516.95 is approved for the 14V LC42/350 and LC41/400 models (see note). Regular capacity, 8.5A/h model.
    • Concorde, RG35A, List Price $395.95 is approved for the LC40/300 model.
    • Concorde, RG24-16, List Price $??? is approved for LC42/350 and LC41/400 models. This is the "high-capacity", 13A/h model.
    • The Concorde, RG24 -15 is not approved for installation in any model at this time.
  2. The List Price for the aftermarket A/C is $42,030.02 and is available via SL-05-010B.
  3. Owners are encouraged to adhere to the Aircraft Maintenance Manual, together with the battery OEM Continued Airworthiness documents available from the Gill and Concorde web sites.
  4. All Batteries and the SL conversion kits are available from CPD2 via the Cessna Authorized Service Stations.

(*) The RG12-15 battery for 300 is listed in Cessna provided info. However, this battery model does not seem to exist as per Concorde.

With this out of the way, you can buy batteries from wherever you want (including, say, Sportys and alike). The CPD2 sourced batteries come with the backing of the Cessna organization (so if something goes wrong, they'll make you whole) while the third party sourcing may come with the lower price tag. It up to you to decide what matters most.


The power grid on Columbia/Corvalis uses relays to isolate bad batteries from the power grid. This prevents a shorted-out battery from draining the good one and also prevents fires (a shorted battery can heat up from the constant charge/discharge cycle and leak or explode). The relay is powered by the battery itself. As long as the battery still has about half charge (14V on a 24V battery), the relay will remain connected and the battery remains attached to the power grid. When the battery dips below this level for any reason, the relay will disconnect it and the battery will now be unreachable. When/if this happens you'll hear a distinct "clunk" sound coming from the back. This is the sound of the relay disconnecting itself.

So what's wrong with that? Well, once the battery drops out, the disconnect is complete. Even with external power, you can't actually charge the battery back anymore because the battery is no longer connected to the charging circuit at all. Lead-acid batteries have a "bounce-back" property that allows them to recharge a bit by themselves if left alone for a while. Simply leaving the battery alone over night, will usually recharge it enough that it will power back the relay and allow external recharge. The effect is not huge (ie. you don't get a full battery from this) but it's usually enough to avoid the worst case. If the battery ends up completely drained though, this won't help.

This is obviously a nuisance and CAM came up with an (optional) Service Letter (SL-07-013B) that will retrofit the power grid on earlier 24V Columbia-s so that external power can/will bypass the relays and reach the batteries even if they are completely drained. This SL is standard on all planes built after about Aug 2007. Unfortunately, this SL is not available at all for 12V planes. So, if you have the SL on your plane, recharging the batteries is a simple matter of connecting external power and turning the various switches on in the cockpit as per the checklist:

  1. Connect a ground power unit to the ground power receptacle and turn it on
  2. Turn on Left and Right Master switches
  3. Turn on Cross Tie switch
  4. ...
  5. If satisfactory results are obtained, shut off cross tie switch, right and left master switches and ground power unit.

(Cessna is apparently working on a separate SL to allow charging of batteries without turning on the rest of the power grid but ... no ETA).

If you don't have the power grid modification on your plane, you can still recharge the batteries through the external power connector as long as the batteries are not completely drained. If they are, the only choice left is to remove the batteries entirely and charge them.


Just to get this out of the way, replacing and charging batteries falls under "preventive maintenance " (remember to record the change in the logbook after that!) and can be legally done by owners.

Chapter 4 of the relevant Maintenance Manual calls out for replacement for lead acid batteries of 1 battery every 2 years comencing with the left hand battery first, then two years later, the right hand battery. This means that each battery will be in service for 4 years once the cycle is established. The battery must be replaced if it exhibits signs of failure irrespective of the calendar limits. The logic of this time limit is that it is prefereble to replace a battery prior to failure during scheduled maintenance rather than it fail at an inconvenient time on a cross country flight for example.

Removing batteries

For 400s, batteries are located under the hat shelf in the luggage compartment. For 300/350, batteries are located on the upper left side of the engine compartment, next to the firewall. Below is the procedure for 400s.

The hat shelf cover is velcroed in. After you remove that, you need to take the battery cover off (the large one. It's screwed in with about 15 screws or so. A power tool comes in handy here). See photo for how it looks like once you remove the cover.
Batteries (400)

The battery is held in only by the electrical cables. Once you unscrew them, the batteries pop right out. Note that the fit is tight so you need to put some (mild) force into it. The cables are pretty thick too and not keen on bending (which is a good thing I guess) so just bend them upwards a bit then yank the batteries out. It took some force to do it actually and I had to get all the way into the luggage compartment to do it without pulling a muscle or something (it's not the force per-se but the angle). Anyway, it's actually pretty easy.

Take a good, long look at the picture above (or better yet, take a photo of your setup ) because you'll have to put the cables back in exactly the same configuration. This is simplified by the cables themselves which are cut to size and, again, not bending much (once you put the batteries back, cables fall back right into place). The charging part is straight forward assuming you have a 24v battery trickle charger and when you put the batteries back you may want to swap positions (old "left" in "right" and viceversa). The left battery works harder and dies sooner.

Alternatively, you can charge them in-place (ie. without removing them) by simply connecting the charger directly to the batteries via standard jump cables (ie. same as what you'd do for your car batteries)

What do you need

  • a 7/16" wrench (for removing the hat shelf net)
  • Phillips screwdriver (for the battery cover panel)
  • a 1/2" wrench (for battery screws)