Trickle Charger 24V Noco G7200

[Nexus_8]

Has anyone used this charger to charge two optima red top batteries in series? Just picked this up at Canadian Tire on sale. When I try the 24V setting I get an error on the charger? I'm getting little useful information from Noco, as to why there is an error. tested the left side battery + positive and ground on the chase it is reading ~26V, both batteries are good with the exception of one battery reading 700 CCA and the other 620 CCA after full charge. Any comments or ideas would be greatly appreciated from my cruiser friends.

 

[John Galt]

That charger has different modes for normal lead acid vs optima type batteries. Be sure it's in the right mode. The manual explains it.

 

[Nexus_8]

Thanks John Galt, yes I did have it on AGM 24V Mode. It could be that it is sensing over voltage on the battery's. Checked it today and it seems to work, after plugging and unplugging the unit. The next question will be what the final voltage is on the individual battery's after charging for a few days. I connected the negative terminal to the 24V ACC box in the left front corner of the engine compartment. next set of battery's will be the yellow top Optimas. Has anyone seen a good price for these?

 

[John Galt]

It will be interesting to see if the smart trickle charger can keep Optimas balanced.

I replaced the import Optimas with CT Nautilus marine starter batteries after the red-tops made it through only one winter.
Been using the marine batteries since, usually getting four winters per set before replacing.
If the truck is unused for an extended time in the winter the smart trickle charger is connected.
The marine batteries have extra terminals that make connecting the charger and linking the batteries neat and easy.

 

[Gun Runner 5]

While I don't have Optima Batteries or a "smart" charger, I've been very satisfied with this little ditty.

 

[John Galt]

While I don't have Optima Batteries or a "smart" charger, I've been very satisfied with this little ditty.

Whatever you think it is, what do you believe it does?

 

[cruiserdan]

His hands are full at the moment so I will respond.

It is a solar panel on the roof of his BJ74. I does a good job of looking after his batteries.

 

[John Galt]

It is a solar panel on the roof of his BJ74. I does a good job of looking after his batteries.

What voltage; how connected to the batteries?

 

[Nexus_8]

Checked the voltage on the two batteries, right battery (newer) showing 12.95V, the left battery is older by 2 years showing 12.80V. Checked the CCA on both newer=~700 and older=~630. debating whether to get the dual 12V charger from (Noco GenMini 2). It seems that the right battery will always loose charge before the left side, connected in series does not seem to do much to equalize the voltage between the two batteries. I will continue to experiment and try swapping the batteries to see what happens with the voltage. Had the red tops since Feb 2011 and I think it has a few more years of life in them if I don't keep on loosing charge. The thing is the alternator charges 24V in series so series charging should work!

 

[cruiserdan]

What voltage; how connected to the batteries?

That I do not know. It was set up by his mechanic.

 

[cruiserdan]

Checked the voltage on the two batteries, right battery (newer) showing 12.95V, the left battery is older by 2 years showing 12.80V. Checked the CCA on both newer=~700 and older=~630. debating whether to get the dual 12V charger from (Noco GenMini 2). It seems that the right battery will always loose charge before the left side, connected in series does not seem to do much to equalize the voltage between the two batteries. I will continue to experiment and try swapping the batteries to see what happens with the voltage. Had the red tops since Feb 2011 and I think it has a few more years of life in them if I don't keep on loosing charge. The thing is the alternator charges 24V in series so series charging should work!

In general terms you now have mis-matched batteries, both in age and capacity. Multiple battteries in this type of application should be of the same brand, size, age and capacity so that they are not "fighting" each other.

 

[Gun Runner 5]

What voltage; how connected to the batteries?

It is hooked to both batteries just as the alternator is and charges both equally at a rate of 1.2-1.5 amps.
Sunshine required. : )

 

[John Galt]

It is hooked to both batteries just as the alternator is and charges both equally at a rate of 1.2-1.5 amps.
Sunshine required. : )

What voltage; how connected to the batteries?

 

[Nexus_8]

In general terms you now have mis-matched batteries, both in age and capacity. Multiple battteries in this type of application should be of the same brand, size, age and capacity so that they are not "fighting" each other.

You are quite right, in a world were I can afford a set of new batteries that would be ideal, but for the moment all I care is to maintain a full charge on both batteries. The proof is in the pudding as they say, earlier the difference in voltage was much greater between the two batteries and now it is 0.15 Volts apart. Since my LC is stored 25 km away I am seeking a plug and forget scenario, continue to charge in series (24V), or spend ~$135 and get the dual (12V) charger and charge batteries independently. Toyota must have considered this when designing the 24V system. Although Noco were not much help in describing the +- of charging using 24V, Others on line are of the opinion that 2 X 12V is the way to charge two batteries in series.

 

[cruiserdan]

I use a Deltron two bank Battery Tender. I like it a lot, it charges the batteries individually at the same time.

 

[elkaholic]

I use a battery tender 24V charger that charges via the same connections methodology as the alternator - ie across both batteries for the full 24v potential

 

[Nexus_8]

I use a battery tender 24V charger that charges via the same connections methodology as the alternator - ie across both batteries for the full 24v potential

What voltage do you see on the individual batteries? I suspect if the voltages are not to far apart, that it should be fine, as I said earlier, nothing like real world experience. From what I understand a fully charged red top 12.6-12.8 V, but then there is the cold V drop / % charge to consider. from what I read, .022 V drop per degree C. I will test voltage again in a week or so and report back.

 

[elkaholic]

With the Battery tender hooked up, I was seeing 13.4 and 13.3 V. The 13.4 was on the battery that the voltage between the + post and chassis ground was 27.2V.

After 6 hours of rest, the batts are at 12.7 / 12.5 wuth the differential the same as hooked up.

The P.O. of my truck had a couple of one sided loads (tapping 12V off of one battery) that he corrected, but I do not know if he balanced the batteries. I will charge each individually over the next two evenings then go back to the 24V battery tender and report back my results.