EB55 Low DC Charge Current from Car

Hey guys,

I upgraded from the AC50s to the EB55 and so far love the upgrade (especially the fast AC charging). One thing I can’t figure out though, is when my car is running I’m only getting about 60W from the 12V cigarette plug that connects via the XT60.

Normally I’d chalk this up to low alternator output, but when the AC50 was hooked up to my Jeep via the same 12V port with a cigarette plug, it was getting over 100W.

Any thoughts?

How much was your EB55 discharged? I was checking the car charging on my EB70 today and it started out at 90 watts and then quickly dropped down to the same 60 watts you are reporting. Mine was over 80% ( above 4 bars) so I was guessing it was starting to throttle down as it was nearing full charge.


Good morning @RhinoOffroad and welcome to the forum!! Like @eric102 mentioned above, as the unit gets closer to getting topped off (typically 80% and up) the charging curve of the cells starts throttling down to elongate the batteries life. Hopefully this is the case in your situation and all is well.

Also these units need a couple complete “cycles” to really get them dialed in properly, so charge it via AC/wall charger to 100% and use it till 0% a couple times if you haven’t already. You’ll probably find better efficiency numbers in doing so also. :metal:

Btw, I’m envious of your eb55 and that dual charging option! Haha I’ve got the eb70 and absolutely love it but that eb55 keeps drawing me in! Haha

This is a really good point. I plugged in it right when I received it and it came with an 80% charge. I’ll discharge it then try again.

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I had it at 80% so I’ll discharge it and give it a shot!

I did some 12v testing on my EB55 and found that it is very sensitive to input voltages so it prefers a regulated 12v source. The highest charge I can get is 75-78 watts at about 13.2 volts. As the input voltage drops so does the charging wattage. At 12.4 to 12.7v its inputting about 60 watts, at 12.3 50-55 watts, at 12.2 40 watts, at 12.0 15 watts and below that zero to just a few watts.

I checked my AC50s and AC200P and they seemed happy to suck in 100 watts at most of those voltages.

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I discharged it to about 20% and it’s charging at 75W, which isn’t bad, but again the AC50 was over a 100W which is strange. Seems to marry up to what you found.

I just bought a 12 to 24v step up converter, so I’m curious to see what my resulting input wattage is. Will report back!


Check this out! I hooked up a 12v to 24V up converter and it is a whole new game for DC charging!

Without it but the exact same wiring, I was averaging mid-70s at 12v.

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Nice, how long did you run it? Which model? I’ve read some bad reviews on some converters overheating/burning up after being on for a while.

Only about 5minutes but I’ll definitely be doing a longer test before install it. I have fused both sides, and it has under/overvolt and fault protection on the circuit.

Here’s the one I bought: https://www.amazon.com/dp/B07BKWG9N2?psc=1&ref=ppx_yo2_dt_b_product_details