MotorGuide is a trademark of its owner. Amp Hour Supply isn’t affiliated with MotorGuide.
The short answer. Read the volts off the head decal first: Xi5-55 is 12 V, Xi5-80 is 24 V, Xi5-105 is 36 V. MotorGuide calls for a manual-reset breaker within 6 ft of the batteries, “50-amp (good) or 60-amp (best)”. Buy the 60. The included 10 AWG cables can grow by 6 ft and no more. The Xi5 manual says nothing about lithium either way.
Volts, amps, breaker
| Model | Volts | Batteries | Max draw (2023 catalog) | Breaker |
|---|---|---|---|---|
| Xi5-55 | 12 | one | 52 A | 50 A good, 60 A best |
| Xi5-80 | 24 | two in series | 56 A | 50 A good, 60 A best |
| Xi5-105 | 36 | three in series | 41 A | 50 A good, 60 A best |
The amp figures aren’t in the owner’s manual; they come from MotorGuide’s catalog. Two of the three sit above 50 A. That’s our reason to say 60 A, not MotorGuide’s; its manual offers both.
The 6 ft cable rule
MotorGuide has no wire-length table. What it has is a limit: don’t extend the included 10-gauge cables more than 6 ft, for 10 ft in all. Past that it sells an accessory cable. The 2013 Xi5 manual calls that cable 6-gauge; the 2014 to 2023 documents call the same part number 8-gauge. And when the motor loses power, every MotorGuide troubleshooting page says the same thing: “Six-gauge wire is recommended.”
Our read: for anything past 10 ft, or on the 12 V Xi5-55 where 52 A runs through the wire, go 6 AWG. Check your own run in the Wire gauge calculator.
Batteries
MotorGuide’s spec is “12-volt, deep cycle marine batteries”, with nothing on amp hours, group size or lithium. Lithium fits that sentence, but the manual doesn’t say so. Our sizing: voltage matches, and the pack’s continuous discharge rating covers the catalog draw.
Xi5-55, 12 V: Pro-Guide 24M100 12V 100Ah Group 24 lithium, 100 A continuous. This is the one Xi5 we can charge from stock: Victron Blue Smart IP22 12/30, set to lithium at Pro-Guide’s 14.6 V.
Xi5-80, 24 V: Pro-Guide 24VM90 24V 90Ah lithium (90 A) or Pro-Guide 24VM115 24V 115Ah lithium (100 A). Or two 24M100s in series.
Xi5-105, 36 V: Pro-Guide 36VM60 36V 60Ah lithium (60 A) or Pro-Guide 36VM75 36V 75Ah lithium (75 A). The 105 only pulls 41 A, so the 36VM60 has real headroom here.
Run time
Run time calculator math, trolling mode: amp hours x 80%, over the amps, warm day. An example.
| Motor | Pack | At catalog max | At half |
|---|---|---|---|
| Xi5-55 (52 A) | 24M100 | 1 h 32 min | 3 h 05 min |
| Xi5-80 (56 A) | 24VM90 | 1 h 17 min | 2 h 34 min |
| Xi5-80 (56 A) | 24VM115 | 1 h 39 min | 3 h 17 min |
| Xi5-105 (41 A) | 36VM60 | 1 h 10 min | 2 h 20 min |
| Xi5-105 (41 A) | 36VM75 | 1 h 28 min | 2 h 56 min |
The 36 V motor goes longest on the smallest pack because it draws the least. Worth knowing before you buy the 80 for a boat that could take the 105.
Grounds, engine battery, charging
The Xi5 manual has a ground rule that differs by voltage. On 12 V it wants a common ground bond to the boat’s 12 V system (no more than one size smaller than the battery cables, never under 16 AWG). On 24 V and 36 V it says a common ground with the 12 V system “cannot be established”. Follow your voltage, not a forum.
Don’t run the Xi5 off the main engine battery; MotorGuide says electrolysis. Unplug the motor to charge, and never charge with it deployed.
Charging the packs above: Pro-Guide’s 24 V packs take 28.8 V, the 36 V packs 43.2 V. We don’t list a charger at those voltages yet, or a 50 or 60 A breaker.
Series wiring for the 80 and 105 is in Trolling motor battery: 12V, 24V or 36V, wired right.
Quick answers
What size breaker for a MotorGuide Xi5? MotorGuide says 50 A (good) or 60 A (best), manual reset, within 72 in of the batteries. The catalog draws for the 55 and 80 are over 50 A, so we’d fit the 60.
Can I put a lithium battery on an Xi5? The Xi5 manual doesn’t mention lithium. It asks for 12 V deep-cycle marine batteries. Any lithium claim is the battery maker’s, not MotorGuide’s.
How far can I extend the Xi5 cables? 6 ft, for 10 ft total, per the manual. Beyond that, MotorGuide’s accessory cable or 6 AWG.
How many batteries does an Xi5-105 take? Three 12 V in series, or one 36 V pack.
Sources
- MotorGuide Xi5 Wireless Edition manual 90-8M0082949 (July 2013), pages 5-6, 16-18, 22, 34-35
- MotorGuide 2023 Product Catalog, spec table and accessory page: https://www.motorguide.com/content/dam/motorguide/owners-resources/product-catalog/MotorGuide_Catalog_3-1-23_WEB.pdf
- Pro-Guide brochures and product pages; Victron Blue Smart IP22 manual (our product page)
- Trolling motor battery: 12V, 24V or 36V, wired right, Run time calculator, Wire gauge calculator
