Eco-Worthy 12v solar panels, Now drifting to... mono vs poly

o.k., thanks.

jrnymn7 wrote:
Thanks BFL, but what happens with the early pm3's after they are modified? Do they go into "boost" regardless of battery V ? Or is it irrelevant, seeing as they can only "drop" to the Op's setting?

Mine (it never had that 15 minute thing, it did the WFCO thing) now just starts out at constant max amps and keeps the voltage going up till the batteries reach the 14.8v I set, then holds that while amps taper.

The adjustable amps PMBC version acts the same way as my mod-PM3 does.

I have not tried to run the mod-PM3 with the batts so low it might do the boost and go to 15.x instead but I "think" I have started a recharge with the batts at say 45% or even 40% and it ran normally. I just don't want to confirm that it won't do a high boost voltage if it ever saw that 13.2 trigger without a specific test.

I also don't know if I left it on at 14.8 whether it would eventually drop to a higher version of its 13.2 float. Usually with these pots, all voltage settings the unit has go up and down together AFAIK.

Thanks BFL, but what happens with the early pm3's after they are modified? Do they go into "boost" regardless of battery V ? Or is it irrelevant, seeing as they can only "drop" to the Op's setting?

jrnymn7 wrote:
BFL,

I'm not sure I understand the 13.2 thing with the wfco. If the batts have to be very low, say 12.2v to kick it into boost, is it the difference of 1 volt that makes it kick in?

And how would an early pm3 handle say 12.5v batts? (both pre-mod and post-mod)

Thanks!

When you turn on a charger, the batts immediately spike from 12.x to 13.x. The WFCO and early PMs and PM3s will only go into boost if that spike is to less than 13.2, so the batts have to be low, around 50% or whatever it needs to be, maybe less than that if wiring is also a factor.

If the batts are at 12.5 the spike will go to 13.5 say (whatever) and be above 13.2, so no boost happens.

Iota and later PMs decided to beat that by having the 15 min thing so it goes into boost no matter what at first. Not sure about Iota but ISTR the PMs after the 15 min check and if the batts are not yet up to 14.2 by then, they continue on in boost till batts reach 14.6, then drop to Vabs of 13.6

If after the 15 min, the batts are above 14.2, it means they must be at a fairly high SOC and will reach 14.6 in minutes, so it just goes straight to the Vabs of 13.6.

PM chose the 15 min trick because they hate the whole idea of having a gizmo you need to attach like the Charge Wizard to hold a "boost button" and they didn't want the added expense of having a built in boost button like the WFCO 98100 has either.

BTW, I still think you have a good case to get that first PM mystery unit exchanged for a working 60 amper that you should have received the first time, but I wonder how you can return that new one when it is not broken. Should be an interesting negotiation! Do remember to stay reasonable or they will react to being pushed by pushing back same as anybody would :)

BFL,

I'm not sure I understand the 13.2 thing with the wfco. If the batts have to be very low, say 12.2v to kick it into boost, is it the difference of 1 volt that makes it kick in?

And how would an early pm3 handle say 12.5v batts? (both pre-mod and post-mod)

Thanks!

OK I get it. So the inadvertent feature is gone. :(

He needs an earlier version of PM3 which does not have the 15 minute thing. That is what I have and then modified. Without the 15 min thing it originally would go into boost only if the batts were really low, using the same 13.2 trigger as a WFCO.

When I used the internal pot to change it up from (no load on the bench) 13.6 to 14.8, it just goes to 14.8 at constant max amps (takes however long the batts take to get to that) and then stays at 14.8 while amps taper. I have to shut the charger off or it will Float the batts forever at 14.8

I don't know how you can tell ahead of time if a "PM3" has that 15 min thing or not. ISTR it would have been mid-2012 when they brought in that 15 min thing (which is good if you want to keep it as is, so it won't act like the dreaded WFCO and be hard to get into boost)

Around the same time, they introduced the "PM4" There must have been some later PM3s that got the 15 min thing before they went all PM4.

It seems the trouble with raising the 13.6 voltage on the newer ones to 14.8 makes it do 15.x for the first 15 minutes, which would be a problem with the batteries connected. If you wait till it drops to the 14.8 after 15 minutes, that would waste 15 min of generator time. Also you want to clamp on first while the thermistor is still cold, so if you wait 15 min with the charger on and then clamp on once it drops to 14.8, that could overheat the thermistor. (means a circuit board repair to replace that RT-1---BTDT)

jrnymn7 wrote:

BFL13 wrote:

jrnymn7 wrote:
Here's something weird. That pm3 I just bought, I bought it on Ebay from boatandrv, but it was sent from Florida, from Errin.

Interesting. Now we get to look again at what exactly it says on the label on the lid, compared with what it does.

Boatandrv makes their "PM3s" sound a lot like PM4s having the fourth stage zap of "equalize" during float every so often, and with PF correction. You are hoping it does not have that 15 minute thing, which some later PM3s might have got just before they went to "PM4s"

No doubt we will be able to hear the howls from there if it turns out all funny :) Do report when you know! :)

Plugged in the pm3. It read 14.77v for 15 minutes, then dropped to 13.6?

... it's going back, along with the other one.

Were you wanting it to be a converter, or were you going to adjust it up and make it a high power power supply? I thought the latter?

BFL13 wrote:

jrnymn7 wrote:
Here's something weird. That pm3 I just bought, I bought it on Ebay from boatandrv, but it was sent from Florida, from Errin.

Interesting. Now we get to look again at what exactly it says on the label on the lid, compared with what it does.

Boatandrv makes their "PM3s" sound a lot like PM4s having the fourth stage zap of "equalize" during float every so often, and with PF correction. You are hoping it does not have that 15 minute thing, which some later PM3s might have got just before they went to "PM4s"

No doubt we will be able to hear the howls from there if it turns out all funny :) Do report when you know! :)

Plugged in the pm3. It read 14.77v for 15 minutes, then dropped to 13.6?

... it's going back, along with the other one.

PWM IMO.