Tool Review: Cen-Tech Battery Analyzer

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Originally Posted By: Vikas
Put a voltmeter and see what it shows under the similar conditions. A running engine should not draw from battery under any (well, at least under normal) conditions. The BAT/ALT light should turn on otherwise.

The small battery is not the problem. Small alternator could be though.

- Vikas


+1 That is what I was trying to say. They do sell high output alternators.
 
Found an interesting result on an OE MB 100Ah group 49 battery in my 240D:

84d801fd.jpg


OE manufacturers do often put more capacity than nameplate into batteries to account for degradation. It likely needs to be a "spec" thing, but leave it to MB to give more than is specified.
 
What temp was it out.. I've found it varies slightly with temp.

I had a 70F battery it tested 750 out of 650.. at 25 it was 700/650
 
Originally Posted By: Rand
What temp was it out.. I've found it varies slightly with temp.

I had a 70F battery it tested 750 out of 650.. at 25 it was 700/650


Impedance is temperature dependent in batteries. The higher the temperature, the lower the impedance. Colder temperatures will mean higher impedance and thus lower power capability (CCA).

I did this at about 40F.
 
Originally Posted By: JHZR2

OE manufacturers do often put more capacity than nameplate into batteries to account for degradation. It likely needs to be a "spec" thing, but leave it to MB to give more than is specified.


Yeah I sold a battery a couple weeks back to a fellow whose old battery was 70% of spec, new one was 750/650. Told him he had a "ringer" and he seemed pleased. Don't usually test new off the shelf batteries. (Fancier Midtronics tester used.)
 
Originally Posted By: doitmyself
eljefino,

This link I posted earlier in this discussion quotes Midtronics saying that these type testers are not accurate in predicting CCA of NEW batteries:

http://4xspower.com/is-conductance-testing-useful/


From that article:

Quote:
What is said above corresponds to what is said here by the BCI:

“Ohmic measurements are not a substitute for capacity testing and cannot be used to predict absolute capacity values.” For full text, see bci_ohmicreadings.pdf

For these reasons XS Power does not use conductance testing to rate our batteries. Instead we use the BCI method of timed high rate discharge and have equipment in house to verify it.

XS Power sells the highest performance AGM batteries on the market. They are built with lead-tin technology which is the highest energy density among the AGM chemistries. When it comes to buying a real racing battery go with the same battery other winners are using right now, go with XS Power!



Well, why would I want to determine Ah (energy, capacity) from an impedance measurement. I think that power and energy are getting mixed up.

A battery may well polarize quickly and not be able to provide energy, yet have retained low resistance and still meet power requirements (CCA) to serve its purpose.

Further, I wouldnt want to deep discharge, especially an SLI battery, as cycle life is VERY limkited and side reactions degrade from the first cycle. Putting high load and pulling lots of energy is NOT a beneficial thing for the battery.
 
Originally Posted By: doitmyself
eljefino,

This link I posted earlier in this discussion quotes Midtronics saying that these type testers are not accurate in predicting CCA of NEW batteries:

http://4xspower.com/is-conductance-testing-useful/


Interesting. It puts on a good show!

The midtronics tester does a good job of trying to be honest and idiot proof, compensating for temp, complaining about poor cable connections, etc. Centech also has the "please wiggle cable" symbol.
 
Maybe I missed it - what is the max CCA input setting that the HF Battery Analyzer can take?
Wonder if it would also work on AGM ups batteries - example C&D 12-475 etc.
Saw a few others on Sears site, but not much data/reviews etc.
 
I’ve had nothing but good experience with the midtronics tester, especially being able to see “surface voltage” but the accuracy with which it measures battery power/health is spot on. Doing multiple tests on the same battery shows that measurements were always consistent with the CCA value ever so dropping as the battery ages. I think it flags batteries once they fall below the 50% state of health, and I could feel slow cold morning starts once a battery reached 30% state of health.

Just a side note, a battery took 7 years to reach 50% state of health where the meter flagged it down and another year to reach 30% state of health when I had to replace it due to slow cold morning starts.
 
Originally Posted By: Donald
I looked at the newest HF flyer I got yesterday and no coupon for this. None I could find at slickdeals either. Other ideas?


Bid to win?

Got mine on ebay... would have ordered from HF if they sold it online. Their loss.
 
Originally Posted By: Errtt
Maybe I missed it - what is the max CCA input setting that the HF Battery Analyzer can take?
Wonder if it would also work on AGM ups batteries - example C&D 12-475 etc.
Saw a few others on Sears site, but not much data/reviews etc.


C&D max rate batteries likely have fewer CCA due to application/design. Ive run it on SLI AGM batteries no problem.

I dont recall the Ah valuation of the 12-475, but the biggest issue is going to be evaluation of impedance.

An interesting test would be to change the cca value and see how the impedance result changes, if at all. That could be compared to the value given in the max rate PDS available at the C&D website.
 
Originally Posted By: Donald
I looked at the newest HF flyer I got yesterday and no coupon for this. None I could find at slickdeals either. Other ideas?


I just printed new 20% coupons good through March from slickdeals. They have an HF thread.
 
I won a used one of these on EBAY and the guy lists the shipping as flat rate envelope. I cannot see how he could stuff the analyzer into a flat rate envelope and make sure its not smashed when it gets to me. I have sent 3 emails on shipping with no response.
 
Originally Posted By: Donald
this one on EBAY reads at any temp down to 32F and one does not need to enter CCA?

http://www.ebay.com/itm/Associated-Equip...e#ht_500wt_1180


So it puts a 125A load on the battery and measures voltage drop and probably relaxation time...

Great.

But if it isnt calculating a battery impedance value, Im not interested. That was the main reason why I bought the cen-tech. Impedance indicates how well the battery will crank, and what the voltage drop will be.

Vt=Voc-IR

Im less concerned with apparent capacity, so long as the power can be taken from it.
 
I think I have discovered the limitations of a battery analyzer. I have the Cen-Tech unit discussed here and have been keeping tabs, roughly once a month, on the battery in my truck. For the last several months the 700 CCA battery has been testing at 60%, about 425 CCA, with a diagnosis of "OK".

A week ago, I went to start the truck and heard a slight hesitation in the starter response that I know is indicative of a low battery. I put the tester on an it showed the same readings as above, still OK. I continued using the truck.

Yesterday the truck would not start. Put the tester on - battery showed NG - No Good. Replaced battery and all is well.

While the tool may be accurate, from a practical point of view I don't think it has much predictive value unless you have some time correlation between the capacity percentage and the point of going bad. Going from OK to No Good in a week isn't particularly helpful. I don't blame the accuracy of the tool. There may be no measurements that could be taken on an occasional basis that might be helpful. It may be simply that batteries "go bad" overnight and there are no advance warnings possible.
 
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