battery upgrade questions

[Merlin]

GK look at the progressive dynamics converters. They're cheaper and highly rated. You can manually put them in boost mode while boondocking too 👍🏻

What does boost mode do for you?

[GrampaKilt]

PowerMax seems to be another affordable quality charger line out of Florida. Many offerings on amazon.ca Prime around the $200 level. Looking at the 45 amp model for $214. Anybody used this brand? Thanks. GK

[GrampaKilt]

My brain is starting to discombobulate...again! Before pulling the trigger on a stand alone 45 amp converter/charger, I looked over the specs for the PD 4045KA power center in the TT and asked myself Why bother? It's 3 stage and 45 amps!

My plan is to install 2-225Ah 6V Trojans, but not more and never a solar system. I understand 20% of Ah for a charge rate is about ideal. The PD 4045 is all I need for effective charging, right? Am I missing something here? (Besides enough neurons) GK

[DavidM]

Your existing charger will do fine with your two GC batteries. While the recommendation is not to charge at more than 25% of your battery's capacity there is no problem with charging at a lower rate. It just takes longer, but if you are plugged in overnight, the batteries will fully charge at even 10%.

David

[ADR]

GK look at the progressive dynamics converters. They’re cheaper and highly rated. You can manually put them in boost mode while boondocking too

What does boost mode do for you?

I just completed installing a PD in my Camplite the last few weeks-

boost mode-   Sometimes when camped where there are abbreviated generator hours- I put mine into boost to get all I can back into the batteries quickly.

I've been in National Parks where they have this wierd schedule for generators- for instance here is what Glacier allows>

"Generator use in campgrounds is permitted only during the hours: 8:00 - 10:00 am; 12 noon - 2:00 pm; and 5:00 - 7:00 pm"

I've even been in a campground where 2 hours is the max you can run your generator each day.

Combined they are enough to fully charge but if you want to leave for part of the day and miss a couple of those windows-  well regular bulk charge won't cut it.   Boost crams a little more in

[Gary M]

Yup, the PD boost mode bumps it up from 13.6v to 14.4v with the push of a button. WFCO converters advertise a 14.4v bulk mode, but that's only when you're battery is below 50%(which you shouldn't be at anyways), and even then, it only stays in bulk mode for a very short period of time, making these very inefficient for charging with a generator. You're basically wasting gas. Additionally, my WFCO 8735 would only supply 15a during the normal 13.6v charge cycle, which is much lower than the recommended charging specs of newer batteries today, and will never fully charge them. My vmaxtanks require a minumum of 30a for 2 of them.

My Cotek charger will stay at 14.7v @ 50a on its own until my batteries are at 85%-ish SOC.   
https://www.progressivedyn.com/wp-content/uploads/2017/05/Charge-Wizard-Tri-Fold-Flyer.pdf

[GrampaKilt]

So my PD 4000 series power center specs proclaim it has a boost mode of 14.4V that will charge the battery up to 90% in 3-4 hours using its Charge Wizard Tech, patented, no less. Yahoo...

Is this all smoke and mirrors?

GaryM et al, To mitigate voltage drop, I'm thinking of doubling up my existing #8 AWG -ve battery feed which theoretically gives me a #5 equivalent. Enough? Also, must I also make a corresponding increase in my +ve line? Thank you. GK

[Gary M]

How far away are your batteries from the charger? I would replace the 8awg with 4awg if the distance is 10' or more. (Just leave the 8awg in place) If you want to get the most out of your new upgrade that is 👍🏻.

[Gary M]

I've found that the Victron Bluetooth monitor I installed is almost as valuable as the battery upgrade itself. Being able to see my exact state of charge at any time from my iPhone is VERY handy, and a LOT more accurate than just reading voltage through the system. I would definitely pick up one of these later on or at some point if you can..

https://www.amazon.com/Victron-BMV-712-Battery-Monitor-Bluetooth/dp/B075RTSTKS

[Gary M]

So my PD 4000 series power center specs proclaim it has a boost mode of 14.4V that will charge the battery up to 90% in 3-4 hours using its Charge Wizard Tech, patented, no less. Yahoo...

Is this all smoke and mirrors?

GK I don't think the 4000 series have the ability to be manually put into boost mode. I think that's only on the 9000 series. Even still, it should serve you a lot better than the WFCO.

[ADR]

How far away are your batteries from the charger? I would replace the 8awg with 4awg if the distance is 10' or more. (Just leave the 8awg in place) If you want to get the most out of your new upgrade that is 👍🏻.

The battery wiring is definitely undersized in my 2018.   The feed from the battery positive back to the charger is 8AWG but even  worse the ground connection to the frame, which LL uses for the negative path from the charger is a bare copper 12-14AWG wire!   
It is of course shorter than the battery positive but still...I wouldn't have done it that way.

So that is another of my "to do" list items- bigger wire on both. 

[Gary M]

Yup, mine was the same ADR. I ran 2 new grounds to the chassis with 4awg. One for the charger, and the other for my battery monitor shunt. Used 4awg for the positive wire to the charger also. My charger is like a foot away from the batteries so I have hardly any voltage loss.

To connect the batteries in series, I used a really thick 2/0 wire(not to be confused with 2awg!)

[GrampaKilt]

Re: PD 4045 power center. I contacted Progressive Dynamics. The tech wrote back that the 14.4 VDC boost mode for recharging kicks in at 11.7 to 11.8 VDC under load.

So let me get this straight. According to the charts, at 12.0 VDC resting, a battery is considered 50% discharged. At 11.8 VDC resting, the battery is 100% discharged. Boondocking, my battery monitor reads 50% discharged and I hook up my genny to recharge. If I've turned off all DC loads, the VDC will probably read 12.0 which means the boost mode does not activate. Presumably, that is why many have commented about the benefits of a manual activation option for boost mode.

Should not the manufacturer be saying that to activate boost mode, one should turn on enough DC loads to drop the voltage to equal or below 11.7 before hooking up a charging source!?? Or, maybe the manufacturer assumes no one turns off all sources of DC draw, so at 50% the VDC will likely be at the trigger level.

If the battery is, by way of example, 70% discharged and I want a quick charge, does this mean I should turn on every conceivable DC draw, and maybe the boost mode will trigger?

My battery monitor should be arriving soon. In the meantime, I'm interested to know what others find are the typical voltages present when at 50% discharge (assuming normal DC usage at the time). Thanks again for bearing with me. GK

[Gary M]

I was going to try their 45a drop in replacement for my WFCO, until I read that the manual boost mode was only available on the 9000's. If you're discharging your batteries to those voltages that the tech rep told you to kick in boost mode, the batteries might not last too long. 12.2v would be my cutoff before running the gen. I wonder how accurate the tech reps statement was because ive seen lots of good reviews on the PD converters.

The good thing about the battery monitors with shunts, is that you dont have to wait for your batteries to stablize with no loads to get an accurate reading. Mines pretty much spot on accurate all the time. Loads on or off.

[GrampaKilt]

GaryM, interesting point about shunt based battery monitors, that is, where voltage is measured matters. And perhaps this concept is the key behind the PD 4000 series converters and their positive reviews.

I now understand that the most accurate place to measure battery voltage is at the battery itself. If a battery is healthy, there should little difference between load and at rest, maybe even fully so. Given that the power center is located downstream from the battery, voltage measured there will be influenced by distance from battery, wire AWG, not to mention a load on somewhere. Is it possible that 12.2 VDC (using Gary's parameter) measured by a shunt based monitor could be 11.8 at the power center?? GK