BLINKING DISPLAYS ON MOTOR STARTUP QUESTION

[johnwater]

I have a common problem that i see lots of different possible solutions, not sure what way to go.
Have yamaha 250 with a dedicated interstate size 31 for cranking.I believe my Talon also directly connected to this battery.
my dock A/C charger is a NOCO 10 amps per bank.lights are always green after period of time charging .
For hds displays(2 Carbons) I have a interstate group 31.
Both batteries are connected into a Blue Seas ACR relay model 7610.
when cranking battery reaches a certain voltage threshold during charging, the ACR relay closes, and sends charge to the electronics battery.This is noted by a Green Led that lights up on ACR.

But after i stop for a while to fish, then go to take off, cranking engine will often, not always cause a voltage drop i guess causing hds displays to momentarily blink,overlay voltage displays around 10.1-10.2 volts.
once i start running motor after cranking battery reaches voltage threshold,Led comes on to charge electronics batt.

I have load tested my electronics battery, always show good voltage, and doesnt lose volts with time, load tester gets hot.
have not messed with Lithium batteries, reading a lot about these, wondering if a good lithium may be better alternative for my electronics battery.if i go lithium, would the blue seas ACR work just as well?
Thanks for any advice
john

[CatFan]

Likely inadequate wiring or bad connections in the power wires feeding the electronics.

[Bradrodfish]

I agree with John. Wiring issue. Size or loose connections.

[johnwater]

thanks for replies guys.
i will go back and check my wiring from switch to fuse block, then from fuse block to red positive,also ground wires .
i know i have continuity,but wondering best way to change wiring, larger gauge to each?
should be very low resistance to all wires i guess, the switch to fuse block and fuse block to power are only a few inches to each.
Anyone know what amount of momentary voltage drop one should expect from a fully charged cranking battery?
john