Ready to go w/ 2 6v batteries: converter/wire question

[bgrasspkr]

After a couple years in a big TT, then a 5th wheel, I made my first motor home purchase last year. I found a 2008 Gulf Stream Super C, with only 5k miles,kept inside in the winters, literally like new condition.

I've learned a tremendous amount regarding battery use and charging techniques on this forum the past couple years. The MH now has a 2 12V Marines, which I would like to replace with two 6v Trojan T-105's. Fortunately, I have room on the tray for these, AND I have a PD 9160 converter, rather than the WFCO(?)s that were in my last two rigs.

The MH has an onboard Onan 5500 Watt gen, and I have a 2k Champion Inverter that I sometimes bring along. I plan on purchasing the Charge Wizard for the converter when I get the new batteries. No plans for solar at this time, just not in the budget with the cost of the batteries.

It is a substantial run of wire from the converter, mounted under the rear bed, to the battery bay in the front of the rig right behind the driver cab. It looks thick, but I can't tell the wire gauge just by looking. The charts that I looked up give pretty similar diameter measurements between 0, 2, 4 etc, so I think I need to measure it to be sure.

Question is this: After purchasing 2 new bats, and the charge wizard, will I be able to get enough voltage across the bats with the existing wiring? How thick does it need to be for the converter to work properly in bulk mode. If my wire is not substantial enough, the thoughts of rewiring, or adding wire, or moving the converter just stresses me out!!

Any help from the extremely knowledgable battery experts on this forum appreciated.

[BFL13]

bgrasspkr wrote:
looks like I buy a hydrometer tomorrow 🙂

Do get the glass tube with bobber kind ($10?) and not one of those plastic sideways things that are hard to operate. You don't need the expensive bobber kind that are accurate down to 100 decimal places or whatever that "some guys on here" insist on. The $10 job will be "good enough".

[bgrasspkr]

looks like I buy a hydrometer tomorrow 🙂

[bgrasspkr]

after wiping some dust off the wires, " ECHB/2 written in black marker. 2 guage wire?? That would be great, right?

[BFL13]

bgrasspkr wrote:
bats were at about 11.9 volts, thus 40 percent state of charge.. ?? Am I missing something 🙂

Thanks everyone for the info, so I should manually keep the voltage at bulk ( 14.x) for approx. how long?

Time unknown. Keep it there till SG reaches 1.275 on your hydrometer, then drop to 13.6 (If they are sulfated and won't go higher than 1.260 or whatever no matter how long you wait, that's it. You now need to do some time at 16v, which your converter can't do. That might not even work, but worth a try)

[bgrasspkr]

bats were at about 11.9 volts, thus 40 percent state of charge.. ?? Am I missing something 🙂

Thanks everyone for the info, so I should manually keep the voltage at bulk ( 14.x) for approx. how long?

[BFL13]

bgrasspkr wrote:
so the wizard has been on the 2 marines for about 3 hrs. Voltage at batteries started at 13.6 and has steadily climbed to 14.2. Wizard still showing bulk, and I guess it will for another hour? Batteries were down to about 40 percent. It will be a good test to see how they perform after a proper charge.

I've been thinking that I have been using a LOT of power with the lights I have in the rig, along with the fridge, and the fantastic fan running at night. I have six banks of the small flourescent tubes( maybe 12 in? ) with 2 tubes in each, on and off all evening. Anybody know how much they draw? That along with normal use of water pump for 4 or 5 people

Going to LED will run between 2-300 dollars for everything. I'm thinking If my 2 current batteries are not shot, this would be a better investment than the two 6 volts for this year anyway. I really don't use anything else that consumes a lot of power.

Lots more testing to do now that I'm on the right track with the proper converter and wizard

Where do you get the 40% from and also 40% of what? (in existing AH as opposed to rated AH)

Once the batts get to 14.x, and amps start to taper, that is the start of the Absoption Stage. This might be at 75% or so or less of full. You want to stay at 14.x until they are full, so if it is still happening (amps not down to 0.5 amp pre 100AH)before the four hours is up, hit the CW again. Don't do the rest of the Absorption Stage at 13.6. Go to 13.6 after the batts are full.

[bigfootford]

bgrasspkr wrote:
so the wizard has been on the 2 marines for about 3 hrs. Voltage at batteries started at 13.6 and has steadily climbed to 14.2. Wizard still showing bulk, and I guess it will for another hour? Batteries were down to about 40 percent. It will be a good test to see how they perform after a proper charge.

I've been thinking that I have been using a LOT of power with the lights I have in the rig, along with the fridge, and the fantastic fan running at night. I have six banks of the small flourescent tubes( maybe 12 in? ) with 2 tubes in each, on and off all evening. Anybody know how much they draw? That along with normal use of water pump for 4 or 5 people

Going to LED will run between 2-300 dollars for everything. I'm thinking If my 2 current batteries are not shot, this would be a better investment than the two 6 volts for this year anyway. I really don't use anything else that consumes a lot of power.

Lots more testing to do now that I'm on the right track with the proper converter and wizard

Batteries will not be fully charged until the SG of the batteries are up to fully charged. Usually a full day or more... The only way to really tell is to measure SG. When ABsorb mode is fiished <> 3 days for sure they will be happy batteries.

You should see 14.4 near the end of 4 hrs... Resistance of the wires are not a contributing factor when the current is low...


Those Fluorescent double light <>12" or so will pull about 2.5 amps each...
The water pump, while pumping will be about 6-8 amps... I would not worry about that.

Here is a hidden draw many will not think about..

If your fridge is dual cooling 120vac and propane then your fridge will be pulling a bit from 12vdc.. when not cooling it will pull about .2 amps and <> .8 when cooling on propane. Hot days it will be in the cooling cycle quite a bit. Example 10hrs cooling mode out of 24 hrs would pull 8ah.. A week out... 80ah.. and you have not even used any lights!

Jim

[3_tons]

SoundGuy wrote:

donn0128 wrote:
Why do you want to cut your available power by a third? Two 6V golf cart batteries will be barely more than one 12V.

What in the world are you talking about? :h A pair of T-105s in series will be 20 HR rated around 220 Amps, half of which is usable at a 50% depletion rate, a pair of G31 12 volt batteries wired in parallel will be similarly rated.

Not so...GC’s can make routine excursions below 50% DOD (depth of discharge) without damage, thus, the ‘usable capacity’ is typically greater yet with the same or similar footprint...

[bgrasspkr]

so the wizard has been on the 2 marines for about 3 hrs. Voltage at batteries started at 13.6 and has steadily climbed to 14.2. Wizard still showing bulk, and I guess it will for another hour? Batteries were down to about 40 percent. It will be a good test to see how they perform after a proper charge.

I've been thinking that I have been using a LOT of power with the lights I have in the rig, along with the fridge, and the fantastic fan running at night. I have six banks of the small flourescent tubes( maybe 12 in? ) with 2 tubes in each, on and off all evening. Anybody know how much they draw? That along with normal use of water pump for 4 or 5 people

Going to LED will run between 2-300 dollars for everything. I'm thinking If my 2 current batteries are not shot, this would be a better investment than the two 6 volts for this year anyway. I really don't use anything else that consumes a lot of power.

Lots more testing to do now that I'm on the right track with the proper converter and wizard

[bgrasspkr]

charge wizard arriving tomorrow! From the comments here, I am confident it will send enough voltage to the bats in boost to do the job. I'll see how it works with the two 12 volt marines I have now, but I'm pretty sure they are shot. I have a couple weeks to get the Trojans, before a week long dry camp.

Thanks to everyone for their input! Greatly appreciated.

[Gjac]

bgrasspkr wrote:
If I'm not getting enough voltage during bulk mode due to wiring issues, can I use my car smart charger on jump start mode ( 75 amps)for a little while? Read only a couple posts about this. Not sure it is safe or practical

I dry camp 95% of the time and do this quite often. I charge at 40 amps and connect the charger up front about 1 ft from the 2 GC batteries using a 40 amp B&D charger. The charger also equalizes and desulfates. I replaced the 2 12 v batteries when I bought it with 2 Trojan 105's, they lasted 4 years the 2 Sam's club batteries replaced the 105's 10 years ago and still going strong which I attribute to better maintenance using the equalizing function of the charger. You can still use your exiting converter/charger (and not change any wiring) once you get home to fully charge the batteries if it has a constant charge feature or maintenance mode.

[bigfootford]

The nice thing about the Progressive Dynamics is that it will stay in bulk mode for the duration of the spec bulk mode charge time... 4 hrs... Even with some voltage loss due to wiring it is going to get those T105's up to <>95% easily.

Jim

[wa8yxm]

To answer your question about "Enought voltage" The answer is yes

Likely the wire is the proper size for the 9160 That is (60 amps) is the number that sets the wire size.

WITH the Wiz you have basically two voltages out of the 9160

14.6 is used for both BULK and Absorption as I recall. Now if the run is long you may not hit the full Sixty amps in BULK mode.. but that's not what tops off the batteries.. Absorption you are only pushing a few amps to the batteries so the voltage loss in even a 50 foot line will be small.

But the BULK charge time may be increased.

Page 3: Trojan recommends a longer, slower, bulk charge in any case

[BFL13]

bgrasspkr wrote:
f you really find that you want more voltage on the battery... get the PD9260-14.8 at bestconverter.com

Will that give me more voltage than the pd9160 with the wizard?

Yes, but why spend $217 for a converter that is "so yesterday" when you can get a modern adjustable voltage (with optional standard 3-stage too) for $100 less?????

The LK can also be used for equalizing even Trojans to their 16.2v spec voltages for that job. What a deal!

https://www.amazon.com/Powermax-PM3-60LK-Converter-Battery-Charger/dp/B01N4L1B6P/ref=sr_1_23?ie=UTF8...