Sterling Power battery charger wire sizes..

wipe_out

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One of my batteries isn't charging.. I quickly tested last weekend before I left and the one output from the charger doesn't seem to be getting to the battery..

So I am planning on replacing the cable this weekend.. I looked in manual on the Sterling Power site and for a 30-50amp charger it recommends 16mm2 to 25mm2 cable, if I remember from my car audio days that's about 4-5 AWG.. The wire that is in there from the charger to each battery is probably 10-12 AWG at best..

Is it really necessary to run such a huge wire from the charger to each battery??

If so the existing wire is seriously below spec..
 
Heavy cables have probably been specified to avoid excessive volts drop. The actual minimum size would depend on the cable length

For 50 amps

Up to 15 ft AWG 6

Up to 25 ft AWG 4

Up to 40 ft AWG 2

The distance is the sum of positive + negative cable length

15ft at 20 amps would be the advisable limit for AWG 10


Trust Mr Sterling ... He knows about these matters


Having said that undersize cable is not likely to be the reason for a battery not charging at all
 
Last edited:
Having said that undersize cable is not likely to be the reason for a battery not charging at all

The size of cable isn't the reason for not charging, its faulty.. Just thought I would check what's needed since I plan on putting in new cables and noticed that what's in there seems very small..

Total run (sum of positive + negative) is probably 15-20ft between the charger and the batteries.. Not 100% sure on the charger output but is we take the middle one at 40A.. So my guess is a minimum of about 6 AWG or relocate the charger closer to the batteries.. :)
 
The size of cable isn't the reason for not charging, its faulty.. Just thought I would check what's needed since I plan on putting in new cables and noticed that what's in there seems very small..

Total run (sum of positive + negative) is probably 15-20ft between the charger and the batteries.. Not 100% sure on the charger output but is we take the middle one at 40A.. So my guess is a minimum of about 6 AWG or relocate the charger closer to the batteries.. :)

AWG 6 is Ok for 20ft at 40 amps
 
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