Questions For Martin

[Compass Marine]

Martin,

Sorry for posting here I tried to send you emails but got no response.

Here are my questions:

Question #1 Lead Crystal Batteries:

I would like to get my hands on some lead crystal batteries. Research leads me to many manufacturers such as EGE battery (China), Betta, Deltec, Axcom etc. but I can't seem to locate any here in the USA? They seem like they are all made in China by EGE or others. Where did you get your lead crystal battery?

I am currently building LiFePO4 packs but they are costly and require charge and loads bus wiring which drastically adds to the total installed cost. These seem to be a true "drop in" for FLA, AGM or GEL and also seem to be a great improvement over traditional LA technologies. I would love to get my hands on some here in the US..

Question #2 Measuring Starting Loads and Transients:

I need a way to measure starting loads on large diesel engines and capture potential voltage spikes and transients. I would like to capture both current 1000+ amps and very fast voltage transients. What would be my least expensive tool to do this with, in the field, in a complete package? I would be more than glad to purchase it through you as I really love your stuff and want to support it. I can't tell whether you actually sell product or just blog?

BTW how much is that multimeter you recorded the LA vs. LC battery data with? Seems very, very useful....

Thanks,

RC

[runem]

I can't answer #1, but I can try #2 if you don't mind.
I found this instrument that can probably do the job. I suspect the price is straight out scary though.
http://www.atecorp.com/products/baker-instruments/exp4000.aspx

I do believe you can get a lot out of a cheap DSO (with some kind of voltage transient protection on the input) and a milliohm meter to measure the resistance of the lead between battery and starter motor.

[Compass Marine]

I can't answer #1, but I can try #2 if you don't mind.
I found this instrument that can probably do the job. I suspect the price is straight out scary though.
http://www.atecorp.com/products/baker-instruments/exp4000.aspx

I do believe you can get a lot out of a cheap DSO (with some kind of voltage transient protection on the input) and a milliohm meter to measure the resistance of the lead between battery and starter motor.

I was hoping to find a battery operated oscilloscope with a shunt or hall effect clamp that can be used to capture in-rush current and voltage transients. Don't want to break the bank but would spend decent money if I found the right combo.

Is Martin usually this tough to get on the forum or get an email response from..?? 

[SeanB]

He has been moving, so has been running around in real life with all the stress that involves. 

Simple battery powered scope can be one of the TEK Scopemeters, or look for something cheaper like the UNI-T UT81B, and then get a plug in current clamp for AC use ( will work for transients as they are AC in any case) or get a DC current clamp if you want DC current ( will have poorer accuracy and a little long term drift but then again this is not for high accuracy measurement more like within 1%) and this gives a DC and low frequency AC scope with a pretty rugged input, a little quirky and definitely needing RTFM to get the best out of it but workable.

[Paul Collins M0BSW]

I have a suggestion for a further program in the future, to follow the great constant load, now Martin brace yourself  how about building a mains isolation transformer, a brilliant newbie project, you could give info for 110v type and 220/240 type, now that would be a very useful project indeed.