XT-90 Project

[H2O Aviators]

Well, I decided to install some XT-90 connectors into my H920+ so I don't have to mess with adapters. I upgraded the power wire to the bistro board to 10awg wire as well. I built the mount out of carbon fiber and screwed it to the factory batter connector mounts. It worked out very well and is very solid!

 

[PatR]

Well done! A very nice improvement over adapter wires. The wire size upgrade for the power supply is a nice touch[emoji106]

 

[H2O Aviators]

Thanks! How are you guys charging these Zippy's, same as the factory ones?

 

[PatR]

Pretty much. 1C rate on dual chargers. I use both the supplied charger and another Hitec X2-400 that I've been using for quite awhile.

 

[Dougcjohn]

Well, I decided to install some XT-90 connectors into my H920+ so I don't have to mess with adapters. I upgraded the power wire to the bistro board to 10awg wire as well. I built the mount out of carbon fiber and screwed it to the factory batter connector mounts. It worked out very well and is very solid!

Very Nice! Great idea, and very clean looking! Hadn't thought of the sandwich board above, very nice idea! No extra leads to contend with too!

 

[Dougcjohn]

Well, I decided to install some XT-90 connectors into my H920+ so I don't have to mess with adapters. I upgraded the power wire to the bistro board to 10awg wire as well. I built the mount out of carbon fiber and screwed it to the factory batter connector mounts. It worked out very well and is very solid!

How are the connectors attached, via the top solder board is apparent... is there a secondary fastener or glue to lower carbon board? Did you make the upper solder mount board, or find that somewhere... if so, can you provide a link?

 

[H2O Aviators]

The lower carbon fiber board is screwed to the original 6 screw locations for the original batter connectors. I just cut the screws shorter and reused them. The upper solder board is attached to the carbon fiber board, with nut and bolt with a plastic spacer, one on each end and one in the middle. I cut 2 holes in the carbon fiber board, just large enough for the XT-90 to slide though. Here is the link for the solder boards: Multirotor XT90 Connector Fixed Mounting Board

 

[PatR]

Thanks for that link. I’m wondering if doubling up those boards might be an idea to provide a bit more rigidity to resist the upwards force of connector insertion.

 

[H2O Aviators]

Its extremely solid, I bought 4 of them, thinking the same thing. And I used the 2mm carbon fiber and when bolted together with the solder plates, it doesnt flex at all.

 

[Dougcjohn]

The lower carbon fiber board is screwed to the original 6 screw locations for the original batter connectors. I just cut the screws shorter and reused them. The upper solder board is attached to the carbon fiber board, with nut and bolt with a plastic spacer, one on each end and one in the middle. I cut 2 holes in the carbon fiber board, just large enough for the XT-90 to slide though. Here is the link for the solder boards: Multirotor XT90 Connector Fixed Mounting Board

Thanks for the info, I could clearly see those components from your great photos.

My question wasn't on the mount itself but the attachment of the XT90's. It appears that only the solder connections are holding the XT90's in place. In other words, if the solder connection broke loose is there anything else holding the XT90's or if you pulled the connection while disconnecting the battery would you pull the XT90 out too?

 

[H2O Aviators]

Ah, I get what you are saying. If the solder joints on the XT-90 solder board break, it is still held in place with the sandwich, this prevents stress on the solder joints. The XT-90 connector has a grove on it to prevent it from pulling through the carbon fiber, so that connector is actually pinched between the two boards and the solder is just an extra mechanical and electrical connection. Thats what makes this so solid. Take a look at image3, and you can see the grove.

 

[OnTheRopes]

Pretty much. 1C rate on dual chargers. I use both the supplied charger and another Hitec X2-400 that I've been using for quite awhile.

Out of interest, if you have a fully charged battery that you need to put in storage and cannot fly down to near storage voltage, do you do a discharge and then a storage or just a storage from fully charged state? What rate do you discharge at Pat?

 

[PatR]

I try not to leave batteries charged more than 4 or 5 days. I leave the discharge rate unchanged from the charge rate as after market chargers on the market seem to generate their own rate that is constantly adjusted downwards as battery voltage reduces. I do not use the charger’s “discharge” function for lithium batteries, only the “storage” function.

 

[OnTheRopes]

I try not to leave batteries charged more than 4 or 5 days. I leave the discharge rate unchanged from the charge rate as after market chargers on the market seem to generate their own rate that is constantly adjusted downwards as battery voltage reduces. I do not use the charger’s “discharge” function for lithium batteries, only the “storage” function.

Thanks, I did try the discharge function once as per a video I found but the discharge rate was recommended as 1A, this took around 6 hours which seemed a bit over cautious to me, but I will stick to storage in future. So far I have used 1C so 4A for the Tattus and Typhoon H batteries

 

[PatR]

1C is generally viewed as a safe rate for most lipoly batteries. Lithium ion do best when charged at a lower rate, 0.7C or so, as they have a charge limiting chip that limits capacity at higher charge rates. Charging them at 1C will show a full charge when he cycle is complete but the battery would not have as high a charge level as when it was charged at 0.7C.

Side note; lithium ION batteries can be stored fully charged, and they have a wider temperature band. -20C to ~60C. Li-on’s are what powers the the ST-16 and -24 transmitters.