Sunday, November 12, 2017

Is your concrete flat?

How to get a flat concrete garage floor? I posted the information below on a forum when I was researching how to specify a flat garage floor and what standard of work could be expected:

What does flat mean? First of all, flat does NOT mean level.

Flat: smooth and even; without marked lumps or indentations. No concave or convex areas. A vertical wall, sloped surface or level floor can be flat (a flat surface can be sloped).

Level: a perfectly horizontal plane with respect to the distance above the center of the earth. A bubble level will show this to be level in all directions

On the high end of concrete floors, you can have "super flat" concrete installed, they do this particularly for warehouses that have high lifts and robots that run in the isles. However, this requires laser guided machines than smooth and flatten the concrete. I don't think many of us are going to do this for our relatively small backyard garages or shops.

There are some standards for flatness and levelness and these are measured in FF (flatness) and FL (levelness) numbers. And these are not easy things to measure. The sell special gizmos to do the measuring. Essentially, measuring with a long straight edge isn't really acceptable, because each person who measures will measure differently. The other obvious problem with using a straight edge is that what you really want to do is hold that edge just above the plane of the floor and then measure below it, you don't want to just lay it on the floor. Companies make cool gizmos to actually measure FF and FL, and they are pretty sophisticated (see

I called a bunch of concrete guys. Essentially, none were willing to commit to a standard like "less than an 1/8" dip below 6' straight edge anywhere on the floor". After my floor was poured and I wanted to make it flatter, I also spoke to a couple grinding and polishing companies that sounded interested in "flattening my floor and they said "oh we can definitely make it flat", but as soon as I mentioned my 6 foot straight edge they lost interest. No one had a plan or a method to make the floor flat. No one said anything about flooding the slab and marking high spots, or anything like that. No one owned an electronic dipstick to measure flatness. I suspect this stuff just doesn't happen in standard residential construction.

I did find one company that seemed pretty competent at flattening concrete floors and their info mentioned they do "slab correction". This guy does lots of work including warehouses that use high lifts that really need flat floors. Essentially, he said my floor was "normal" for work these days (sadly). He could make it better and wasn't wildly expensive, he'd charge just somewhat more than a regular floor polishing for the extra time and effort. But he questioned making an effort to get it really within 1/8".

I found this chart online:
"Although there are no direct equivalents between F-numbers and straightedge tolerances, ACI 302, "Construction of Concrete Floors and Slabs," gives the following table of approximate values:

F-number Gap under an unleveled 10-foot straight edge
(fraction of an inch)
FF12 1/2
FF20 5/16
FF25 1/4
FF32 3/16
FF50 1/8

Apparently typical concrete floors are in the FF20 to FF25 range. I did find this statement: "Although "1/8th inch in ten feet" has been used to specify billions of square feet of concrete, it was seldom, if ever, achieved. The typical industrial floor, for example, is closer to a 5/8th inch deep envelope, rather than a 1/8th inch deep envelope."

A big issue is that typical concrete guys never check their work. How many visit the site 30 days after the pour and measure the surface with a proper dipstick style gauge according to the standard? So essentially, your residential concrete guys do not really know how good or bad their work comes out!

I'm a geek, so when my concrete cured enough to walk on, I went out and tried a 6' straight edge all around the floor in a grid pattern. I really tried about 40 placements. Only one area was out of whack. Mine may not be that great, but I also suspect very few people have garages that would really meet the FF50 (1/8") standard.

On contracts. I've been around the track a couple times and I understand these things. It sounds great to have everything specified in a contract and to have it be enforceable. In my case, I didn't know enough to ask the details about flatness, let alone specify something. But at least around here, it wouldn't be easy to even find a residential contractor with a dipstick gauge who would commit to an FF number. The other problem is that the residential finisher is usually a subcontractor who makes a modest wage. Even the head contractor , unless he is a big outfit, isn't in a financial position to "replace your foundation" if it doesn't work out. Certainly, the finisher, who is maybe making $250 to $1000 is going to disappear before buying you a new slab. I personally think you are just far better off trying to understand what you can get, checking references, and looking at similar work than expecting the contract to make it "all right". In my case, yes, I wish the floor was better in one spot, but I can live with it and I'm not going to make others pay for something I didn't understand well enough to demand better.

So, in conclusion:
I'm no expert on concrete, but having done this once, and read some others advice; here are my recommendations:
- You aren't going to get a "perfectly flat" floor, especially with high PSI concrete poured on a warm dry day.
- It seems harder to make a floor with a curb (stem wall) around the edge flat (especially with just one pour) than a slab without a curb, as the finisher cannot use the top of the form as a guide when there is a curb. If you are going to have a curb/stem wall, perhaps look into doing the floor as a separate pour.
- Talk with the actual finisher, not only your general contractor, about what he can do. Make sure he knows this is going to be your "pride and joy", not just another lousy garage. Make sure he has a wide bull float and will run it both ways, North-South and East-West. Is there enough room to run the float both ways or are other buildings in the way? Go see similar work he has done and if it matters bring a dipstick or at least a straight edge. Does he own a dipstick? Has he ever returned to a job after it has cured and tested the floor's flatness?
- During the job, have him show you it is flat, while it is wet. Maybe they can go out with skis and show you a straight edge on the surface.
- Don't let any of the finishers hang out on their skis on the floor. If they stay in one spot too long they will make a depression. (My low spot just happens to be were a finisher hung out playing with his phone while he waited for the concrete to get a bit dryer.)
- Lastly, If you can get it close to a 1/8" gap under a 10 foot straight edge, you are doing amazingly well. 1/4" is probably more reasonable.
- Be present during the pour and finishing, ask questions, and make them do it right.

PS: On sloping the garage floor vs making it level: 
Most people slope the garage floor so liquids will drain toward the car door opening. This can be particularly important in places where it snows or rains significantly, and it maybe part of the building code.
Often, concrete finishers who slope the concrete significantly care much less about flatness. The more the floor slopes, the less likely water will puddle! Typically, builders who slope floors do at least 1/8 inch per foot (1 inch in 8 feet). If the floor is sloped sloped significantly, many people will want to level things like workbenches, shelves, and floor mounted tools with leveling feet. And if you must have leveling feet for the sloped floor anyway, flatness may not matter as much to you.
But be careful with floor slope; some builders will slope the floor as much as 1/4 inch per foot or more. That would be 1 inch of slope in 4 feet. It's also 4 inches in in 16 feet. Many would consider that too steep for many garage uses.

Wednesday, November 1, 2017

Proto, SK, old Husky USA (and Tekton) Combination wrench comparison

Proto, SK, Old Husky USA (and Tekton) Combination wrench comparison

(Top to bottom: SK, Proto, old Husky USA; 7, 14, 22mm)

It was my birthday recently, and after a beer I decided that maybe I should upgrade my old Husky USA metric combination wrench set. Now I love my old Husky's and have had no issues with them. The only negative thing that comes to mind is that on some heavy pulls the narrow beam can dig into my hands a bit. But otherwise I really like the almost dainty, jewelry like feel of the polished Husky USA wrenches. (I also have heard that some older Husky tools had some issues with the "made in the USA" mark, but regardless, the quality of mine has been fine.)

I should also say I work on old vintage stuff and I do some restoration work. I cannot really accept wrench damage to my fasteners. I typically use 6 point sockets on everything I can get them on, and I use box end wrenches occasionally and only use open end wrenches when necessary or it doesn't matter (like spinning an already loose bolt or working on something that I don't care as much about). I don't want any special ridges or teeth on the open ends that could "bite-mark" the nuts and bolts, so that eliminated Wright tools' WrightGrip and some of the other options.

Also, all my work is metric, but recently I ordered an inexpensive Tekton SAE set for those rare occasions I need a wrench with inch markings. (I won't reveal the horrid tiny open end wrenches I had been using when necessary before that!) So I have those Tekton wrenches for comparison too.

After finding I had a couple different brands of wrenches in my hands I thought other people might be interested, I decided to take a couple minutes and write this review comparing the sets.

First I ordered a full set of SK, the "SK 86224 SuperKrome 19 Piece 12 Point 6-Millimeter to 24-Millimeter Combination Wrench Set", $244.74 from Amazon. This arrived promptly, but I was surprised that this ships from SK in a brown cardboard box with the wrenches jangling inside a plastic bag. No individual cushioning or packing material at all. Also included were two plastic rails to hold the wrenches in your toolbox, but they were nothing special. The wrenches themselves seemed properly made (I saw a previous garage journal poster had some issues with his set). Some had a tiny bit of marking, possibly from shipping or storage, but nothing they wouldn't get with some light use. They seem to have a fatter beam, and that may be more comfortable to some in the hand. But, I was surprised how short they were, especially the small sizes! I don't think my old huskies were "long", but as I said, I was surprised. Short wrenches can be a great thing as they can help prevent over-tightening, so maybe that is good. I would think that being fatter in the beam would make them heavier than the other brands, but being shorter seems to even things out. I noticed that the open end's aperture is a bit less deep than on my old Husky USA wrenches. That seems functionally fine, just different. The SK size markings are only on one side of the wrench, which can be could be an annoyance. Very nicely, the set includes all the full millimeter sizes from 6mm - 24mm.
For me, in summary, I wasn't thrilled by the hand feel / extra thickness of the larger SK wrenches, the small ones looked tiny to my eye, and I just wasn't convinced I preferred them to my old Husky USA wrenches. Now, I should say, if you like a fatter wrench, without any open end gimmickry, you may love the SK wrenches. I do particlualy like the sweep of the wrech up to the box end.

So then, not being perfectly happy with the SK set, I ordered a set of Proto wrenches: "Proto J1200RM-T500 17 Piece Full Polish Combination Wrench Set, Anti-Slip, 7-24mm", $239.66 shipped from Zoro. These arrived in a colored cardboard box in a red cloth tool roll. I must admit I preferred this to the way the SK's clattered in the box. To my surprise, the Proto's are VERY similar to my old Husky USA wrenches. A quick bit of research showed the old Husky USA wrenches were likely made by Stanley/Proto. Hmm. The new Protos seem to be the same as my old Huskys except for the antislip design of the open end and they are just a bit longer and some have with a bit more angle on the closed end. To my eye, the "antislip" design seems to be just a bit of relief where the outer corner of the nut would be, so that most of the force falls away from the corner. There are no sharp ridges or teeth. For me, working on restorations, that seems good. Below size 10mm, the wrenches have normal open ends (no antislip design). I note the Proto, like the Husky, conveniently have size labels on both ends of both sides. It's dissappointing the Proto leaves the 23mm wrench out of this set. (Interestingly, my old husk set from 7mm to 22mmm skipped the 20mm! Who makes thses silly decisions?) Adding the 23mm and 6mm to the Proto set so it has the same sizes as the SK set would cost an additional $58 on Amazon.

Frankly, all of these wrenches seem good. Even the Tektons look nice next to the higher end wrenches. On the SK side, for the very close to the same price as the Proto, the SK set is more complete including the 6m and 23mm sizes. Personaly, I prefer the familiarity of the feel of the Proto (so very similar my old Husky) and I want to try this Anti-Slip Design" stuff. I'm hoping it will be a bit better than standard, and won't mark my fasteners.

On the other side of all this, I've found my old Husky USA set looks pretty good compared to these new sets. Frankly, when I place my first order, I had expected a bigger difference from the SK and Proto sets. If it wasn't for a little interest in this Anti-Slip design stuff, I would not not bother with anything newer.


(Top to bottom: SK, Proto, old Husky USA; 7, 14, 22mm)

(Top to bottom: old Husky USA 14mm, Proto 14mm, SK 14mm, Tekton 9/16")

(Same as last picture, other side of wrenches. Note SK has no size markings on this side)

(Proto Anti-Slip design on 14mm wrench)

(Proto Anti-Slip design on 14mm wrench, other face)

(SK above Proto; 7,14, 22mm)

(Proto above old Husky USA; 7,14, 22mm)

(SK above Proto; 7mm)

(Proto on left, SK on Right; 7mm. Note deeper aperture on Proto)

Tuesday, October 10, 2017

Surface rust removal test: Evapo-Rust

Need to remove the rust from inside a motorcycle tank and I heard good things about a product called "Evapo-Rust". Figured I'd test it first. I rusted a steel 6" x 6" plate by spraying it with salt water and then leaving it outside for a couple weeks. Then I dipped it into the miracle fluid for 2 hours. Looks like it might work!

Ok, so here are to sliding rods from my 1950s drill press. They both had about identical rust. I soaked one for two hours, then rinsed it in water and dried it off. Pretty good!

Monday, October 9, 2017

Tiger Tools 16" Drill Press

Check out that cast aluminum feed arm! Just bought this beautiful old drill press.
It is a  "Tiger Tools" 16". The 16" refers to the 8" distance between the chuck and the column. It means you could drill a hole in the center of a 16" round work piece.

Apparently it is from the early 50's, likely made in California.

The company "Tiger Tools" seems hard to find, but is likely this place:Tiger Tools, Inc. filed as an Articles of Incorporation in the State of California on Monday, August 17, 1953.
Apparently that company was dissolved in 1955.

Tiger Tools was a subsidiary of Karl-Douglas Associates which was known for making cylinders, valves and even parts for the F-104. Both were acquired by Thompson Products in a stock transaction in 1955 and their Hawthorne, CA operations were consolidated into TP's Bell, CA plant.
More great info from the researchers at OWWM:


Sunday, August 13, 2017

Restoring the Truck Headlights with the 3M 39008 Headlight Lens Restoration System

      BEFORE                                                               AFTER

The headlights on the truck were just starting to get too scratched/fogged. Besides just looking ugly this greatly reduces the headlight's effectiveness. And for my truck, replacement headlights are expensive. But it is worth checking the price of replacement headlights before polishing yours!

I spent about an hour and a half polishing the headlights. Most of that is just taking my time with the procedure. I suspect you could do it in under an hour.
I used the 3M 39008 Headlight Lens Restoration System, about $14 bucks on Amazon.

Here are some pictures of the polishing process.

Before. If you enlarge the picture you can see the haze and scratches better. The lens wasn't horrible, but was well worth restoring. Note this lens is fairly flat so it is relatively straightforward to polish. I wouldn't try this on a lens that had bumps, shelves or ridges as that makes the process much harder.

After P500 grit. The first step is the hardest, emotionally, because the headlamp looks much worse before it starts to look better after the following steps.

After P800 grit. Just cut to a finer level:

After the 3000 pad wet sanding. Now it is starting to get clearer!

Now, if you are using the 3M Quick Headlight Clear Coat, you should skip the next buffing step, wash the headlight well, clean it with alcohol and go directly to clear coating. The clear coat needs the slightly rough surface left by the 3000 pad to adhere properly, and the clear coat will fill that roughness in. See the bottom of this post for more detail.

If you don't clear coat, buff away:
After the buffing compound and waxing. It looks great!
If you shine a light across it, you can see fine scratches from the polishing, but it is vastly improved from before the process. I've heard that that the lens may now deteriorate more quickly than a new one, as the factory finish has been removed.  We will see how long it holds up. But for $14 bucks and an hour and a half of my time, I think this is a great result. Note that the cheapest replacement headlamps I could find were over $150 a pair and would have taken at least this long to install.

7 month follow up
Still looking good! Just the slightest fogging in a few spots.


28 month Update! It's definitely tine to do the headlights again.

The polish lasted well for a year, and then by the 2 year date it was looking pretty bad. At this point, 2 years and 4 months, they are unacceptable, bad enough to definitely affect how the headlights work. They are not yellow, just foggy looking. So I'm redoing them today.

I am using the same 3M 39008 Headlight Lens Restoration System as last time, but I have added the 3M Quick Headlight Clear Coat, part number 39173.

This is actually a great kit and a time saver. The quick coat goes on after the 3000 pad wet sanding, so you never buff and polish the headlight. I think the idea is that the clear coat needs a slightly rough surface to adhere well.

Here is the headlight after the second clear coat.

It will be interesting to see if this lasts longer with the clear coat's "Extreme UV Protection".

Tuesday, August 1, 2017

Fitting a Ferracci 2 into 2 full exhaust system onto my 2000 Ducati 900S

Here is another old post (from 2004) that I'm moving here from my old website...

So, here is my tale of putting a pipe on my 2000 Monster 900S.

I ordered a Ferracci full system 2 into 2 low pipe in December. But it didn't fit. Ferracci was nice, and would have let me return it, but I said NO WAY, I just want one that fits! They swapped the header for me, but the new one was about the same. Here was the problem: The rear header was too close to the swingarm by the chain, and the chain would hit the header and would eventually cut it. Here is a pic of the lack of clearance for the chain:

Note the melted plastic swingarm protector! This is because because of the angle of the pipe: as the swingarm rises, it gets CLOSER to the pipe. Thats why you see the plastic has melted in an arc matching the shape of the pipe, it hits! If you look very closely, you can see the scratches from the chain on the pipe in this shot:

This is a bigger problem than it looks like, because in not long, the chain WILL cut through that pipe, just like a chain saw. This isn't acceptable. There was also an issue under the swingarm where the crossmember would move up and contact the pipe as the swingarm moved up. Unfortunately, I couldn't get a good picture of this. But if you fit a pipe inspect carefully how the swingarm moves upward and check how the clearance closes between the swingarm crossbrace on the engine side and the pipe. (I'll note that these issues may not be a problem for Monsters with the steel swingarm, but 2 separate pipes from Ferracci had this problem on my bike. Also note that Sil is the original manufacturer, so this is probably an issue with their pipe too!) The main problem was that the rear header had much less bend in it that than stock one. See this comparison shot, with the stock pipe on the left:

So how to fix it? First, the pipe needed to be opened a bit: I needed just a little more length between the front header and the rear. I made this rig to stretch the darn thing:

Stainless steel is darn hard to bend. Even heating and then jumping on the 2x4 shown had little effect. It helped some, but not enough. Hmm. Time to cut:

I had the rear header pipe cut at the top and the bottom: Top cut:

Bottom cut:

Note we didn't cut the pipe completely apart. This let it hang together and helped us position it. With the cuts made, it was fairly easy to fit the pipe and then tack weld it in the proper position. Then it was removed and welded solidly back together. With the new bend, the pipe bend looks a lot like the stock pipe, no surprise there! Stock pipe on the right:

Clearance to the chain was solved:

But there still wasn't quite enough clearance underneath the bike, where the inside swingarm crossmember would come up and hit the pipe. The simple answer there was to ding the pipe to provide clearance:

Finally! Done and ridable! Hmm... I think Ferracci should give me a big discount on my next purchase! This was not an easy to fit pipe! But the pipe sounds great! I also put in the airbox kit and power commander. But way back in December, before any modifications, I did a couple 'stock' dyno runs. The "before" run is box stock. The "after" run is with the FbF Full 2 into 2 low system, Airbox cover removed and BMC filter, and power commander. Interestingly, the run showed the power commander map as provided by Ferracci was very good and really didn't need to be tweaked. Actually, the curves are nice and smooth. You can see I gained a nice chunk of torque and power across the rev range. In fact, you can see smack in the mid range at 5000 RPM a 7.8 ft-lb torque gain and a 8.2 hp gain. At that RPM this is a more than an 17% gain in horsepower and torque!

Some of this looks to be due to the really lousy stock air fuel ratio, but regardless, the FbF kit seems to have done a great job.

Thursday, July 6, 2017

Setting the Ignition Timing on a Ducati Single

More than 10 years ago I wrote a web page about the now arcane process of setting the ignition timing on a Ducati single. This method can also be used with all sorts of other single cylinder bikes that have points.
I have since taken down that old website but I wanted to preserve those instructions. They are now attached to this blog and can be found with this link:

Sunday, June 18, 2017

Lithium (LiFePO4) Battery Charger Review and Comparison: OptiMate vs CTEK vs NOCO Genius

A while back I did a review of a lead acid battery chargers that has been one of my most popular posts, so when I needed a new lithium battery charger I decided to do another review and test. Here it is!

Some background on lithium battery chargers

I've been using lithium-ion batteries in my motorcycles lately.  Technically, these are lithium iron phosphate (LiFePO4) batteries  These are also sometimes called LFP batteries (and sometimes incorrectly called LiPo; this a slightly different technology). For ease, I am going to call them "lithium batteries" in this article.

I have both Shorai and Antigravity brand batteries in my bikes. And as it happens, I had two bikes with lithium batteries in storage for more than a year. Neither bike is in "running condition" so I thought it was time to charge their batteries.

Now most people may never need a special charger for these lithium batteries. If there is no drain on them, they can go a LONG time without charging (probably more than a year). So don't run out and buy one of these special chargers unnecessarily. If you need to leave your vehicle for more than a week or so, just disconnect the battery and don't worry about it, even for months.

Shorai publishes a nice chart of showing how you can use your battery voltage to estimate much charge your battery has left:

And if your battery charge does get low, Shorai explains how you might be able to charge the battery with some "regular" chargers here: Note that you can NOT hook a lithium battery to a just any lead acid battery charger and forget about it! You need the right kind of charger and it is a careful procedure, read and follow the directions.
More detail on the problem using a regular lead acid charger with a lithium battery: Many or most electronic type lead acid battery chargers have a "desulfation mode" which cannot be turned off.  That mode will damage a lithium battery! Also, the final voltage for a lithium battery is different (higher), and a regular battery charger will not handle that.

Now, probably the THE BEST way to charge a lithium battery is to get a special charger with a Balance Management System that can charge the battery through the "Balance Connector", if the battery has one. This allows each individual cell in the battery to be "fully topped off". The Shorai does have a balance connector and Shorai sells a special charger for that port. If you want to buy a specialized charger like that, it's probably the best way to go!

On the other hand, many brands of lithium batteries do not have the special balance connector. Some of the manufacturers claim to have have a built in cell balancing circuit (EarthX is one). Others claim (like Antigravity) that it isn't necessary, and some just don't say anything.

Another feature of some lithium batteries is an "over-discharge protection circuit". If the battery is in danger of being drained too low, it disconnects the actual internal battery from the terminals on the battery's case. If the battery has triggered the protection, it cannot be charged until that protection is reset, this is often called "BMS reset". If the battery is not reset, the charger does not recognize that it can be charged. The manufacturer EarthX describes this well on their website.

What do I want in a lithium battery charger?

Because some of my batteries do not have balance connectors, I wanted a a charger specialized for charging lithium batteries without a Battery Management System that requires the special connector. A lithium battery charger should work using somewhat different charging steps and voltages and should definitely not have a desulfation mode. The charger should also be able to reset any over-discharge protection circuit inside a lithium battery.

The Contenders

A little research showed 4 chargers that interested me in the US$50 to US$100 price range on Amazon. Here is a list with the manufacturer's web page for each and also a link to the manual for each:

Noco genius G3500 3.5 Amp UltraSafe Battery Charger and Maintainer

User Guide
(about $60 on Amazon as of this writing)

Frankly, I wasn't thrilled with the regular lead acid Noco charger I checked out back in 2012. But I thought I should check them out again.The G3500 is a fairly hefty 3.5A charger, so that was good. And it is a multipurpose charger that works for lead acid 12V and 6V batteries as well as 12V lithium batteries. They claim "8 modes" in the manualbut I think this is a bit of over-marketing. For instance, one of the 8 is "Standby" which is essentially "Off".  Regardless, it will work with multiple battery types, and if that is useful to you, that is a good thing.
But I was evaluating how this charger would work for Lithium batteries and I found some things I didn't like. The manual claims an 8 step charging sequence... but it doesn't say anything about how it works differently, if at all, for a lithium battery. Perhaps the charger's lithium mode just skips the desulfation step and ends in a voltage appropriate for lithium batteries? There is no way to know. The manual also doesn't describe any way to reset the BMS on batteries that have that built in.
So... I rejected the NOCO and I did not buy one to try it.

tecMate OptiMate Lithium 4s 0.8A TM-471

User Guide
(about $60 on Amazon as of this writing)

The OptiMate Lithium comes with lots of great recommendations. At least 3 of the battery manufacturers recommend or resell OptiMate chargers: Antigravity, EarthX and Ballistic.
So I ordered one of these up and checked it out.

Sadly, I found the LEDs hard to understand. Even with this key from the manual it isn't perfectly clear:

Here is what the manual says about LED #5 and #6:
VOLTAGE RETENTION TEST: LED #5 flashing Delivery of current to the battery is interrupted for 12 hours* to allow the program to determine the battery's ability to retain charge. For batteries with a good state of health LED #5 (green) should continue to flash for the full 12 hours* period. Read the section NOTES ON TEST RESULTS on reasons for poor test results or how to test a battery that returns a good result but cannot deliver sufficient power once it is returned to service. 
MAINTENANCE CHARGE: LED #5 / 6 steady on For 30 minutes the circuit offers current to the battery within a safe 13,6V voltage limit whilst the result of the voltage retention test is displayed. If LED #6 (red) indicated the VOLTAGE RETENTION TEST will be repeated. A steady LED #5 (green) indicate the 30 minute float charge maintenance periods follow and alternate wih the 30 minute REST (no charging) periods until the battery is disconnected. The battery can draw current as required to support small loads and counter self-discharge.
Is that clear? It means that LED #6 will go solid green when the charging is completely done.
But note what the manual says about the "Voltage Retention Test", LED #5. It says this test lasts for 12 hours! And guess what... it wasn't true; when I charged my Antigravity battery (which wasn't badly discharged at 80%) the "Voltage Retention Test" alone went on for MORE THAN 24 HOURS (this is in addition to the time required to charge the battery before this). And note, this is a relatively low powered charger, at 0.8A, so it isn't particularly fast anyway.
Now, I really like the idea of this test. And obviously, you could just disconnect the charger before this test is completed and use it. But I was annoyed by the strange LEDs. This charger should have the LEDs all in a row like the other brand chargers, and a clear indication when the charging is DONE and then a clear indication the 24 hour charge retention test is happening. 

Also, while some Optimate chargers can reset the "over discharge protection circuit" on some batteries, it is not clear that this charger has that feature. It isn't mentioned in the manual but the website does say it has this feature. It would be nice to mention the feature in the manual if it is included in the device. I think it is probably in there...?

In summary, I wasn't thrilled with the OptiMate charger.


(about $80 on Amazon as of this writing)

Here is what came in the box:

The CTEK is a lithium battery charger only and charging steps are clearly described in the manual. There is also a linear array of LEDs on the charger that clearly show the progress of the charging.
Check out these two pages from the manual:

Perfectly clear and concise! So refreshing after the OptiMate manual. Note how it clearly shows how to reset the "over discharge  protection circuit" in a battery that needs that.

The unit itself is handsome enough. I do wish it was rubberized on the corners to protect it from drops and some rubber feet would be nice too. It does look like it will become scratched and worn over time. But note the nice and simple LEDs, the clear reset button, and the voltage and current rating right on the front.

Here is a closeup of the LEDs:

The manual page above clearly indicates which steps/LEDs indicate the battery is "READY TO USE" (step/LED 3) and "FULLY CHARGED" (step/LED 7). Tip to CTEK: This really should be printed right on the label, there is plenty of room! I may add a sticker to mine as a reminder.

So I tried the CTEK on my Shorai battery, and it worked fine. The battery was at about 85% charge when I started it, and when I went back a later it was fully charged. No problems and easy to understand.


My choice: The CTEK Lithium charger. It has the most clear manual and good LEDs. It clearly states that it can reset an "over-discharge protect circuit" and has a button for that feature. The manual clearly describes how it's steps work on the lithium battery, including the voltages used and how long the steps should take.