Cable to battery

me and my team are arguing wether or not it is allowed to use electric dominoes (like the one on he picture) to connect the battery to the main breaker. Do you guys have any informations since we can’t seem to find an answer on the Game Manual ?

where were you planning on using them. R40 and R41 would be the main ones to consider

No it has to be a minimum 6 AWG (and a pair of SB-50s or SB-120s) wire between the breaker/PDP and battery, rule R40. No other devices or modifications allowed.

You’re only allowed to use the Anderson SB50 to connect to the battery. Having anything else will fail inspection.

We are planning to use them between the Battery and the Main Breaker and maybe between the Main Breaker ans PDP


Using the electrical dominoes like the one in the picture provided with the post
These one téléchargement

ok. How were you planing on using them?

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There is no where in the rules that such a device is allowed, in the wiring between the battery and PDP. So it doesn’t really matter how they intend to use them, unfortunately.

If you were going to use them to extend the cable to the PDP, you can buy 6 awg wire in red and black along with the crimps that you need to make your own cables.

Here are some links from andymark

PDP and breaker crimps
Battery side connector
10 ft of 6 awg red wire (stranded(do they even make solid 6 awg wire))
10 ft of 6 awg black wire (stranded)

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This is not true.

It’s half true. Per R40, no connectors other than Anderson SB-series* may be in the battery-to-breaker-to-PDP circuit. Use of crimp-on lugs where the cables connect to the battery and breaker are implicitly assumed.

* You may use other SB-series connectors (e.g. SB120) if you like.

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R40 implies otherwise.

The one (1) ROBOT battery, a single pair of Anderson Power Products (or APP) 2-pole SB type connectors, the one (1) main 120-amp (120A) surface mount circuit breaker (Cooper Bussman P/N: CB185-120, CB185F-120, CB285-120), and the one (1) CTR Electronics Power Distribution Panel (PDP, P/N: am-2856, 217-4244, 14-806880) shall be connected with 6 AWG (7 SWG or 16 mm2) copper wire or larger, with no additional devices or modifications, as shown in Figure 9‑9.

I suppose it technically allows for any “Anderson SB” connector, but I would heavily recommend sticking with the SB50 anyway.

Also, the inspection checklist does not mention the connector…so…have fun!

“with no additional devices or modifications”
In reading the rules, FIRST has been very particular in calling out the power connection from the battery to the PDP. Nowhere do they call out compression lugs for terminating the wires. I think I’ll continue to use those, anyway!

To the OP:
Are you having trouble making the pre-fabbed harnesses work on your robot?

Aside from legality, you don’t want to use these on the main battery wiring (or really any other wiring) on the robot. These connectors have a much higher resistance than a properly soldered or crimped connection, meaning your voltage will drop significantly with high current draws. They are also not permanent, so as the robot takes hits and vibrations they will loosen and their resistance will get even worse, to the point where they may eventually come disconnected completely.

Legally, Your ground must go directly to the PDP, and the positive from the battery runs to the breaker and then the positive from the breaker runs to the PDP. All connections must be 6 AWG and no longer than a certain length (Consult manual for the exact length). Between the battery and the start of the robot’s power system there must be a set of SB-50s for battery changes.

To amplify/correct a bit: 6AWG is the MINIMUM size, and SB50 (being the smallest of the Anderson SB series) is the smallest connector you can use. The only rule limitation on wire length is between the battery and it’s SB-series connector (12" on each leg); you can put as much wire on the robot side as you like, consistent with the weight limit (but keep it short because long runs turn your battery energy into heat rather than work).

Refs: R5 (wire length) and R40 (the rest).

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And even then, so long as you have like 15 pounds to spare in your robot weight, you can use longer battery wires than 12".

EDIT: Nevermind, this isnt/might be true, but isnt explicitly called out in the manual.

Definitely not true. The purpose does appear to be to keep you from padding your weight with battery cable, or alternately keeping your robot core weight down by moving some excess to the battery. But even if you have a 60# robot core*, your battery side cables must be no longer than 12 inches.

robot core: my internal term for the robot without bumpers or battery