Got 4Ah, not 5Ah, battery 18V (20V) - done right thing?

I post what I've seen at reliable sources, it's as cautious as the battery manufacturers choose to be.

Personally I test batteries by loading them down with a carbon pile until they scream for mercy, and rarely mention the results because they vary so widely. I tested stuff to and beyond its limits professionally and have acquired or built the gear to find those limits at home. I don't blow up batteries any more but I have tested circuit breakers to destruction.

UL "safety" testing is -dangerous-, much smoke and flame. The old theatre curtain recipe of dipping cotton cloth in a solution of alum and borax really does let it pass the vertical burning test.

To be fair... My experience is that you still get useful power out of the "moderately" large batteries like your 4AH as opposed to 5AH. It just may not be "as powerful." Where you see huge differences in base power even over a very very short time is the smaller batteries. Often the "cheap" batteries packaged with an all in one kit. Tool/battery/charger... They don't give you full power for a short time. They just don't give you full power at all.

To be fair... My experience is that you still get useful power out of the "moderately" large batteries like your 4AH as opposed to 5AH. It just may not be "as powerful." Where you see huge differences in base power even over a very very short time is the smaller batteries. Often the "cheap" batteries packaged with an all in one kit. Tool/battery/charger... They don't give you full power for a short time. They just don't give you full power at all. Bob La Londe CNC Molds N Stuff

---------------------------- If you could access the electrical circuit a PZEM-051 meter would give you all the useful data. For under $20 they measure DC up to 100V and 100A, calculate the power and the total energy in Watt-hours.

Torque Test Channel does some decent testing using a load. I don't need to be an expert on the details. I just need to know the results, and remember my anecdotal, but not irrelevant, direct experience.

I never was employed doing destructive testing, but I did spend a decade or two doing low voltage communication contracting. I learned there is what they say, and there is what there is. Usually what they say fell short in my field, but sometimes it didn't.

When they say an IR motion sensor will detect motion at 90 feet they mean if ambient is below 70F and the subject is large and is running a fever. LOL. They don't say if ambient is 90+ its virtually worthless.

Seriously there are thousands of bass boats that don't have room for 4 big deep cycles batteries running just three in series for the 36V TM and tapping the positive of the ground battery for nominal 12V for cranking and accessories. The big thing is to charge as soon as they cool down (or get back to the hotel), and to have three equal batteries.

With most pros running 20-23 foot glitter barges these days most have plenty of room in the back for batteries, but some older boats and/or smaller boats didn't. Many have also switched over to a single high voltage lithium for their TM battery for motors upto 48V. I wonder how they do on the Potomac in a winter tournament before sunrise when the water gels on the line and freezes in the reel. The lead acid deep cycles would work. Something has to keep the lithiums from dropping to ambient temperature.

Anyway, this is all tangent of tangent now.

With cylindrical lothium batteries the cells are all pretty much the same physical size regardless of their published capacity. All pretty much induatry standard 18650 format. The difference between battery PACKS of different capacities will be either the composition of the cells or the number of banks. If limitted to the number of banks capacity differences will be the cell capacity X1. X2, X3, or X4 - with the physical size reflecting the difference. Battery cell composition - different chemistries or different construction, will give less distinct "multiples" af power and no change in physical size. An 18/20 volt battery is composed of 5 cells in series, 0r 2 series sets of 5 arranged in parallel, or 3 sets in parallel - etc. For a 4Ah and 5Ah to be composed of the same cells the

With lead acid batteries things get more interesting. The grid design, link design, lead alloy, and acid capacity all come into play (along with the separator material) before even taking case size into account. (or acid strength). Basically the weight of lead in a battery is a pretty good predictor of capacity - but whether that weight is arrives at by plate thickness or plate density makes a BIG difference

- primarily by the difference in "paste" capacity.

Deep Cycle, SLA (Starting Lighting and Accessory) or Marine (combination) are all designed and built differently.Whether flat plate or coiled. Real good "deep cycle" batteries are most often "pure lead" while antimony or calcium alloys are generally used in SLA and Marine batteries. Marine batteries are generally built to withstand more vibration without degrading ling connections or dislodging the paste - through both plate design and separator material. Some cheaper batteries address the plate material issue by providing deeper "acid wells" below the plates to allow more shed material to accumulate without shorting the plates - at the expense of smaller plates - while at the other extreme you get starved acid, or AGM (absorbed glass mat) batteries there there is NO SPACE between the separator and the plate

- meaning no plate material can effectively leave the plates - and ONLY the rquired amount of acid is contained in the battery - allowing for maximum plate vol;ume and mass for the battery case dimension. AGM batteries are highly vibration resistant, and pure lead versions make ideal deap cycle batteries although not NECESSARILY suited for high current output.

When sizing a "battery bank" endeavour to use the highest capacity cells you can get, connected in series, rather than higher voltage batteries connected in parallel - for a 36 volt pack use 6 big 6 volt batteries in series rather than 2 packs of 3 12 volt batteries. The

The same can be said with Lithium (or other chemistry ) Large cells connected in series makes a much better traction battery than a couple bushels of 18650 cells or double A cells bunched together into a battery pack

Just keep the trolling motor running under load and the batteries will stay warm. Don't stop for a beer!!!

Something has to keep the lithiums from dropping to ambient temperature. Bob La Londe

------------------------------- Insulated cooler? Don't forget and add ice.

Some LiFePO4s use charging current to warm themselves above freezing before applying it to the cells.

On 5/18/2024 7:33 PM, Jim Wilkins wrote: ...

I never was employed doing destructive testing, but I did spend a decade or two doing low voltage communication contracting. I learned there is what they say, and there is what there is. Usually what they say fell short in my field, but sometimes it didn't.

When they say an IR motion sensor will detect motion at 90 feet they mean if ambient is below 70F and the subject is large and is running a fever. LOL. They don't say if ambient is 90+ its virtually worthless.

--------------------- Most of the testing was to find and reject or reclassify parts that didn't meet specifications for companies that cared, or burn-in testing to weed out early failures by operating at elevated temperature for a week. The exact conditions were usually secret, I had to provide a range of adjustment. Sometimes there had to be provision for destructive failure, such as Chrysler Lean Burn engine controllers with components not rated for possible under-hood temperatures.

Before Congress mandated emissions and fuel economy standards that needed electronic control to meet, the only electronic device in a car was the radio which the auto makers bought, they had to hire new engineers unfamiliar with the heat, water, dirt, salt and vibration, who took time to learn. I had the partial advantages of military electronic experience which solves those, in commercially unaffordable ways, plus a hands-on apprenticeship in custom electro-mechanical machine design. The engine compartment environment can be nearly as challenging as military aircraft specs, consider a snow plow driver in Alaska starting cold and diving full throttle into the deep snow in front of the truck, or splashing through an icy puddle.

Heat in the South is another issue that's not so evident in Michigan. I know what Atlanta is like in summer.

Bell Labs had material test sites down here in the Sonoran Desert for environmental testing. Death Valley may be the only place in North America more hostile than the low Sonoran Desert. They had panels setup with material samples affixed out along the southern rail line right of way. Maybe they still do (if they are still some form of Bell Labs). I haven't checked in a long time.

When sizing a "battery bank" endeavour to use the highest capacity cells you can get, connected in series, rather than higher voltage batteries connected in parallel - for a 36 volt pack use 6 big 6 volt batteries in series rather than 2 packs of 3 12 volt batteries. The

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I've seen that advice several times and priced it out, finding that 12V

I'm not a fan of Michigan weather. My wife used to go to the Wheatland Music festival every year and of course she convinced me to go one time. Middle of summer. Should have been fine. It rained everyday (most of the day) and we camped out. I was cold and wet the entire time, and of course I felt like I came down with a cold the second day... and she volunteered us to work the info booth one shift every day. Can't say how many times I said, "Ice truck is that," "Bathrooms are that way."

When I was a kid I wanted to live where there was snow and trees. Now... No. I am good right here. Yeah the heat is miserable, but its familiar, and my office is air conditioned. Actually, so is my main CNC machine room now. The rest of the shop... well an ice tea tastes so much better when I get out of the main shop and back into the office.

Yes I used to ride year around in it too.

It's only the last couple of years I haven't ridden year round . My wife says I'm gettin' old , but I don't believe her . It's just that I have so much here to keep me busy ... and well , wrasslin' an 800 lb touring bike around the yard to where it's parked isn't as much fun as it used to be . The planned gravel work may change that .

You can put on extra clothes until you are warm - you can't take off enough to be cool - - - Personally There is no place like the area dead between the lakes in South Western Ontario. In the summer it can be uncomfortably warm and humid for a few weeks- sometimes not even cooling off over night - so air conditioning (in home and car) is pretty well mandatory - and we get numerous thunder storms - but we are just south east of Ontario's "tornado alley"so seldom get SERIOUS storms - and the winter is moderated by the lakes as well - very seldom get long periods of VERY cold weather - and in the little stretch of heaven called Waterloo Region we've been in something of a "snow shadow" for the last several decades, getting less snow than areas to the North, west, and even south ( as little as 15 miles away can have significantly more snow).

You can put on extra clothes until you are warm - you can't take off enough to be cool - - - Personally There is no place like the area dead between the lakes in South Western Ontario. In the summer it can be uncomfortably warm and humid for a few weeks- sometimes not even cooling off over night - so air conditioning (in home and car) is pretty well mandatory - and we get numerous thunder storms - but we are just south east of Ontario's "tornado alley"so seldom get SERIOUS storms - and the winter is moderated by the lakes as well - very seldom get long periods of VERY cold weather - and in the little stretch of heaven called Waterloo Region we've been in something of a "snow shadow" for the last several decades, getting less snow than areas to the North, west, and even south ( as little as 15 miles away can have significantly more snow).

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New England to your east is generally similar though the meandering Jet Stream can bring us weather from the Gulf of Mexico, Hudson's Bay and everywhere between. Hurricane Katrina passed over here after hitting New Orleans.

The early settlers expected our climate to be similar to southern Europe's at the same latitude, not deep snow and extreme winter cold more like Scandinavia. Half of the Pilgrims died the first winter. Being retired I don't have to drive in storms and can keep the wood stove going all day, so I can enjoy the good weather and not be bothered by the bad. Your Canadian air is very pleasant in summer.