Ping Jim Wilkins - Lithium Ion Jump Starter and Power Pack at Harbor Freight

The PMGR starter is almost universal on late model Fords. They look like a compact standard starter.

I thought maybe you had done a life-cycle analysis to figure out what the actual cost would be, including investment, fuel, and installation, less labor (for DIYers like us).

That's only a bit over a year/month. Seems =quite= low. What is your depth of discharge (DOD)? I bought cheap deep cycles to start so I could get a feel for the DOD and power use. They're easier to replace if I somehow screw it up. :-/ I'll invest in Trojan or Rolls/Surette after a year or two of play/learn-ing. Some charts:

Why my battery box will have insulation. We seldom get below 20F. I'm wondering if a 12v seed germinating mat would be a good idea, thermostatically controlled. I have several relays...

- May the forces of evil become confused on the way to your house. --George Carlin

You told me about those a while back and I ordered some. I have a couple of those and some 50A shunts (a bit more precise than the 100A shunts that came with 'em and only $5 apiece), and I have a couple of the little blue watt meter boxes, so I can check input and output voltages all around the systems.

The little blue meter shows that I have 356.8Wh with the HF system. The deep-cycle group 27 is 2 years old and the group 24 car battery is who knows how old.

- May the forces of evil become confused on the way to your house. --George Carlin

How could I do one for emergency standby equipment? The best outcome is that I -never- need to use it.

Again, my solar system is for emergency backup instead of daily use. I've only discharged it a few times to keep track of how long it runs the fridge. The APC1400's low voltage shutoff sets the end point, but although that voltage is constant the DOD at shutoff depends on the current drain since the battery's interrnal resistance rises as the acid concentration decreases.

This is how the run time varies with current:

If you multiply the Amps by the Hours you see that higher currents correspond to less apparent capacity, due to the internal voltage drop. The 'missing' charge is still available from the battery if you can decrease the load current demand.

I think deep cycle batteries are usually rated at the 20 hour rate.

In experiments with resistor loads I see the battery slowly recover above 11.5V after tripping out at between 9V and 10V.

SLA1 and 2 in Steve Duncan's test may have had one weak cell that increased the resistance, since they recovered to over 12.0V after dipping below 8V. I've cured that in flooded batteries by charging at >15V and low current, but it didn't work as well in sealed batteries.

-jsw

The meter that went bad (from static?) was a 100V 20A model. Its voltage reading slowly crept higher and higher although the voltages on the input divider resistors were correct.

Blue is 60v 100a.

- May the forces of evil become confused on the way to your house. --George Carlin

They aren't as accurate as the display resolution suggests at low currents. Mine is good only to 0.2A. The lowest digit is random.

There's now a volt + ammeter that reads both positive and negative current.

It needs an isolated power supply, not included, to allow the differential current sense inputs to float above the negative supply. I have an older current-only meter that apparently puts one of them at the A/D reference voltage, which may be half scale. I bought some DC-input isolated power modules to replace its AC-powered supply but I haven't checked them out with the meter yet. There may be switching noise to filter out. It takes two modules in series to match the meter's 100V input range, one to step the voltage down and another to isolate the output.

I monitor the unidirectional currents out of the charger and into the load rather than into / out of the battery, which works well for Lithiums but not Lead-acids that waste some of the charging current by generating hydrogen.

Depth of Discharge can be determined either from the electrolyte specific gravity or the cell voltage after resting a few hours, neither being practical for a computer to monitor during the discharge, so I can't determine the DOD until the battery is depleted. Then the Energy reading on the meter shows the remaining Amp-Hour capacity (at that load current) to estimate DOD later.

Lithiums have the same problem. The indicated DOD assumes they haven't degraded. The remaining runtime estimate for a laptop will become increasingly overoptimistic until the DOD calculation is reset by a full discharge cycle. The "remaining capacity" of a laptop battery that hasn't been discharged for a while may suddenly drop from 40% to zero, then after the controller recalculates the capacity, the estimate will be more accurate at a lower total.

--jsw

True. But I have no idea what the life cycle is for the little gensets and thought you might. The last generator + solar figure I saw was from, hmm, maybe 15 years ago, about $0.50/kwh, or $0.25 for solar alone on a 25 year amortization. I don't recall the array size.

How does the APC voltage suite compare to a standard controller? I have a couple controllers to play with, 100A @ 24v supposed MPPT and a

45A @ 24v PWM. One of these days, when the ice is off the roof, I'll get the panels up and start diagnostics. In the interim, I have to get some sheet metal or ABS and make a few bezels for the solar control center.

I get a 404 error on that page.

Yeah, that's what I've been seeing.

That's the flooded desulphation voltage innit? AGMs don't seem to suffer from that as much, if at all, from what I've read. I wonder if it's not a cell-connection breakdown in AGMs rather than sulphation.

Rebuilt lithium pods for electric cars are becoming available at semi-reasonable prices ($1,500 to $4500) but the catch is the core requirement. They won't take 200 motorcycle/UPS batteries in trade, for some reason, darn it.

- May the forces of evil become confused on the way to your house. --George Carlin

Small import generators are rumored to wear out in a few hundred hours. I don't know the long term reputations of the Honda inverter clones that HF and Kipor sell. If I'm lucky I won't need to run mine long enough to find out.

"The standby power draw [of an APC] is horrific compared with the off-grid inverter; 50W compared with 10 - 15 or so. Overnight when only the fridge is running the APC UPS would be the main power draw."

It's a known issue that they don't like the AC from portable generators, and not just because of the ungrounded Neutral.

OTOH this APC was free for the fixin' and the UPS function works as well on the fridge as the computer, during storms when outages are likely. I had to reconfigure it for the external batteries, which required tracing and re-engineering the cables.

I've read that APC may have done something to newer models to discourage or block this unauthorized long-term battery operation. I dug up the programming commands, make the custom serial cable, turned off the warning beeper and increased the number of battery packs it thinks it has. I don't draw more than about 200W from it except for short tests.

-jsw

Yeah, that's why I took your advice and got the pair of Bayites, too.

Just how handy might those be? I don't see a real need instantly, plus they display less total info by half.

Love the Churchill quote more than the math.

So, calculating DOD is a good way to set up systems, but less accurate for flaky old sh*t? Got it.

- May the forces of evil become confused on the way to your house. --George Carlin

When I'm experimenting I like having current meters on power supplies to show normal and fault conditions, such as current inadvertently being forced into a power supply from a higher voltage. That's less of an issue for the simple stuff I do at home than it was for testing prototype integrated circuits like Hot Swap and Power Over Ethernet controllers with multiple supplies connected. You don't always know whether a pin will sink or source current. It may do either depending on the applied voltage. The simple example is a resistive voltage divider. Another is a solar panel.

You can determine it from voltage with Lithiums but not so easily with Lead-acids.

--jsw

Since I'm in start-up mode, I'm more interested in theory right now. Countin' trons, y'know?

- If ever the Time should come, when vain and aspiring

Men shall possess the highest Seats in Government,

our Country will stand in Need of its experienced

Patriots to prevent its Ruin. -- Samuel Adams

Ouch. I picked up that maybe-MPPT for $45.99, and it has a It's a known issue that they don't like the AC from portable

It seems like an awful lot of work to end up with a mediocre product. Was it a "jus cuz" project, or were you able to program it to exactly what you wanted, or what?

- If ever the Time should come, when vain and aspiring

Men shall possess the highest Seats in Government,

our Country will stand in Need of its experienced

Patriots to prevent its Ruin. -- Samuel Adams

The search terms are "coulomb counter" and "battery gas gauge".

-jsw.

A rheostat load test showed that my panels produce nearly the same power from 18V to 14V. The current rises as the voltage drops. I've read that MPPT makes more sense for higher voltages and arrays over

200W, which I don't have.

The APC1400 holds the batteries at 13.6V, just short of gassing. It was set there for sealed batteries when I got it and the same voltage works for wet deep-discharge ones as long as I equalize them higher occasionally with a different charger. A little fizzing appears around

13.8V and 14.3V is the published value where gassing becomes a concern - the actual rate is difficult to measure, or estimate without chem lab experience. My HF "45W" controller shuts off at 14.2V. About once a year I carry the batteries outdoors and take them to 14.8V where they bubble freely.

I've performed industrial experiments on battery hydrogen generation but the results are proprietary. The above was from testing at home. I actually measure and record to the milliVolt for experiments and have two decimal place meters on the batteries to monitor them. One decimal place +/- 1 count allows too much uncertainty for me.

The lower cost true-sine inverters I looked into had poor reviews, notably for generating interference. My TVs and cellular internet transceiver can't tolerate much RFI. I replaced the spark plugs in a neighbor's riding mower because the ignition noise was jamming evening weather reports. When the flea market dealer offered me the APC1400 with swollen batteries that he didn't know how to remove I had my answer.

The problem is the refrigerator:

I can use the woodstove or in the summer a camping stove for hot water and cooking so the fridge is the only thing that needs continuous AC. It draws 12A for 0.3 seconds when starting, requiring a fair sized inverter, then drops to 80W.

The APC does what it was intended to quite well. I run off it when doing critical computer jobs like flashing a later BIOS or backing up important files to ac-powered external drives. People just can't avoid crashing into phone poles here, plus the greenies are shutting down power plants and protesting improvements so our safety margin is shrinking.

Demand here already spikes above supply in the coldest weather.

I've added external battery connectors to my other smaller UPSs too. They won't necessarily run longer near full power than the internal battery would allow without overheating, but the connectors let them go a long time below 100W and I can check the voltage and equalize the battery.

-jsw

I hear that. Hopefully, the cloning process gave another 8 lives.

From the dirty/square output and GFCI problems? (Hmm, my UPS just cycled and the lights dimmed for half a second.)

My concern is for my Carrier Infinity HVAC system. It's a 120v electronic unit with variable speed DC motor (part of the reason my electric bills are lower). When the power goes down, I'll probably want heat, so my inverter will likely have to be a decent pure sine wave model. The existing is a 2kw HF mod sine, and might not do. My well pump is 240v, so my long-term grid-down dilemma is: do I go with a 240v inverter plus step-down xfmr for heat and lights, or a 120v PSW inverter with step-up for pump, or add an installable 24v replacement pump and replumb as necessary? The simplest solution is to win one of the many multi-million dollar lotteries and do all the above (plus a metal roof and another 15kw in solar) for redundancy.

- If ever the Time should come, when vain and aspiring

Men shall possess the highest Seats in Government,

our Country will stand in Need of its experienced

Patriots to prevent its Ruin. -- Samuel Adams

SCRs don't work right with a "modified sine wave" which is simply alternating plus and minus 170V square pulses, narrowed to equal the RMS power level of a 120V sine wave.

I'd consider adding an extra water storage tank and picking up a fixable 120/240V gasoline generator to run the pump when the tank empties or you are showering. Your water heater could be receiving room instead of ground temperature water to heat.

I bought an old 3750W Coleman for $100 to run my washing machine and air compressor after needing both during a week-long outage. Both draw over 30A starting current. The Coleman doesn't play well with the APC but it's fine for larger power tools. It just needed a little carb work.

I assume that the storm that caused the outage will do damage I need to repair quickly. The 1998 ice storm left a dozen holes in my roof from a fallen tree top, the 2011 "Halloween" storm damaged the roof of my tool shed. In '98 I had only a 500W ham radio generator that would run no more than a sabre saw, or recharge battery tools. Luckily my Makita 9.6V panel saw was the perfect tool to repair the plywood.

'easter "In some areas of Connecticut, outages lasted as long as 11 days."

-jsw

I have 180w panels putting out 44.89Voc and will be running a 24vdc system, so it does make sense for me. Do you have only the HF system?

I'm surprised that I didn't lose more water on the HF system, as it's on the south side in the sun all year. It did corrode the terminals, so I brushed it all off to bright lead, reinstalled the clean cables, and sprayed it with battery terminal protector. That stuff works just great.

Wow, a snow plow just went by my house. First time for me! It was a mere 4WD pickemup with blade on the front, but still...

Picky, aren't ya? ;)

Yeah, good deal. Smart call on the neighbor's mower. An hour of your time and (what $10?) your interference is gone.

50% isn't a bad inductive starting surge, but you sure notice them when you're on battery, don't you?

Egad! 83 pages of PC doublespeak. I've been distrusting of grid power stability for 25 years now. I lost pages of critical info I had just typed into the word processor (auto-save hadn't been available) when the power flickered for milliseconds, just long enough to reboot the computer. I haven't been without a UPS since then, both for the stereo/DVD and computer. So, when the power does finally go out, the first to cry out are those same Greenies, chanting "Our government will save us!" before they start screaming "Effing FEMA. WHERE ARE YOU?" Warms my heart, it does.

- If ever the Time should come, when vain and aspiring

Men shall possess the highest Seats in Government,

our Country will stand in Need of its experienced

Patriots to prevent its Ruin. -- Samuel Adams

The pump house is now fully insulated, but it still gets down to 40 in the winter and up to 80 in the summer. But that is another possible solution. Thanks.

The easiest fix for a long-term grid problem is probably a 120v PSW inverter and 120vac pump, since they'd be a do-it-once then hands-off forever. It'd be a real hassle to go out several times a day to crank up the genny to get the pressure up on the water, or listen to the noise all day if left on.

Best guess is that the phone/DSL would be down along with the power. I'd be looking for shelter, heat, water, and power to cook. In a pinch, I can set up the camp woodstove for heat and cooking. The HF solar set can power my kindle, which still has over 100 unread books on it, saved for that purpose.

It's amazing to think that so many people practically throw away because of some simple problem. I have harvested hundreds of them along the way. Vacuum cleaners with a cat toy blocking the intake or broken belt. Golf cart with a bad battery cable. Tons of gas weed eaters, tillers, and mowers with plugged/gummy carbs or bad gas. Power tools with broken switches, or cords, or ends. I love it!

That's why I took out 4 trees on my lot. Anything within range of the canopy is a target when (not if) the tree goes down.

Yeah, I remember that and was really, really glad I lived on the opposite coast. This snow we're getting is unusual, but it isn't sticking. It melted and snowed again 3 times today. The norm is one year out of four (or 2/5, worst) for snow down here, and even then it's only an inch or two for a day or three.

Y'all can -have- your real storms, TYVM. I wonder how hard this one is going to affect the rest of the country. 2x-4x worse, I'd wager. Got preps?

- If ever the Time should come, when vain and aspiring

Men shall possess the highest Seats in Government,

our Country will stand in Need of its experienced

Patriots to prevent its Ruin. -- Samuel Adams