Thread: Problem Charging Aux Batteries with Smart Charger

Originally Posted by drivesafe

If you have achieved this once, you can do it at anytime, it will just take a little longer.

Or a shorter time from now on in, if you do it on a regular basis.

Thanks for all all your help Tim .......and on a final note ....if my batteries are getting to full charge and float is it safe to assume they are ok ......or can they still not hold charge ?
Ill keep an eye on them over the next few days see how the voltage holds

This is not a 100% guarantee but as it took so long to get them fully charged, it is a fair indication that they are OK.

Originally Posted by LRD414

Anderson direct to Optima and ctek lead direct to crank. I’ve made a ctek to Anderson adapter lead.

Scott

Not that it is relevant to your (now solved) issue but I made up an adapter for the Anderson plug on the back of my work truck. I cut a square 6mm U-bolt in half, added heatshrink and it allows me to connect anything with alligator clips.

773_IMG_20171018_104429.jpg 891_IMG_20171018_104456.jpg

Originally Posted by pop058

Not that it is relevant to your (now solved) issue but I made up an adapter for the Anderson plug on the back of my work truck. I cut a square 6mm U-bolt in half, added heatshrink and it allows me to connect anything with alligator clips.

773_IMG_20171018_104429.jpg 891_IMG_20171018_104456.jpg

That's pretty cool ....but why not just fit an anderson plug in stead of the alligator clips ...

and what gauge of wire did you use to get the power from this modified anderson plug back to your battery ?

Originally Posted by drivesafe

This is not a 100% guarantee but as it took so long to get them fully charged, it is a fair indication that they are OK.

Thanks Tim ......I'll watch the voltage and see how I go

Originally Posted by DiscoMick

If batteries of different sizes are connected they may equalize at the capacity of the smallest battery, so the larger one may not be fully charged.

Not true.

Originally Posted by D4206

A further question regarding charging the start battery and optima via the Anderson plug..... I've connected the Ctek charger to the Anderson plug and checked voltages at both the start battery (14.7v) and Optima battery (12.4v). Does this difference in voltage mean that only the optima is being charged? I thought both batteries would be charged at the same time.

Originally Posted by DiscoMick

They could be connected but still give different readings.

Not the difference quoted unless there is significant voltage drop across the connecting device due to a large current flowing.

Originally Posted by DiscoMick

What size is the alternator in these vehicles - 80Ah?
If it is then the alternator is (thinks carefully to avoid usual dodgy maths abilities) 16 times more powerful than a 5Ah battery charger. So it is certainly a lot more powerful.

No. Alternators are rated in amperes, not Ah, ditto with chargers. I'd expect the alternator to be up around the 100A range these days.

Originally Posted by landoman

That's pretty cool ....but why not just fit an anderson plug in stead of the alligator clips ...

and what gauge of wire did you use to get the power from this modified anderson plug back to your battery ?

My small compressor, lead light and battery charger all have clips on them from the OEM. By retaining the clips I can still use them directly on any battery on any vehicle.

Originally Posted by drivesafe

While I would expect it might eventually go into float mode, but because of the voltage drop caused by the 8B&S cable and possibly some bad connections causing more voltage drop, it may never go into float mode.

I must admit I wasn't sure of the size of 8 B&S or 8 AWG so I did a bit of hunting around and found this page: Wire Gauge Comparison Chart

8 B&S/AWG is only 1/8" or 3.25mm diameter. That's really quite small. I'd prefer to see at least 6 B&S/AWG. Not just for the lower resistance but for the maximum current figure in a jacket (not in air which is about 3 times greater). See AWG Wire Sizes