mgianzero

I own this Century charger (see pic) that I've owned for years, but I don't find it to be a great tool for determining the wellness (strength or charging cycles left) for our older batteries. What do RL experts recommend as a good battery charging / tester device for car batteries? (It would also be nice if it worked on motorcycle 6V batteries too.)

I also own one of the Porsche trickle chargers which I keep on my vehicle when not driving. This tends to work well, but there's no way to figure how "good" or strong your battery really is.

IXLR8

I am assuming you know how to determine that a battery is accepting a charge and when it is fully charged or what state of charge it is in.

Tests are done on fully charged batteries.

Two tests tell you everything about a battery's state of health.

• a load test (quick and easy)
• a capacity test (time consuming)

I personally do not bother with conductance testers; they're not all that good.

Get a 500A carbon pile load tester at Harbor Freight. They go on sale and can be had for something over $50.

A capacity test if you are looking for accurate Ah numbers takes expensive equipment like our Torkel-Programma unit. A cheap way is hooking up a couple of headlights and recording the time till the battery reaches 10.5V and doing some rough math.

Furthermore, unless you are running total loss (broken alternator belt - reserve capacity of the battery), all you are really interested in is starting ability and that boils down to a load test.

mgianzero

Alex,

So glad you answered my post as I consider you a wealth of knowledge in regards to things electrical!

Actually, I'm thinking of getting a more sophisticated capacity tester. I'd really like to know how worn down our batteries get with our cars. I confess that I sometimes forget to trickle charge my Porsche. So I end up driving it after a quick charge and the battery seems to take a hit each time I do this. I'd hate to get stranded with a worn battery when I could have known ahead of time.

I also own a few other devices that use a 6-V motorcycle battery or equivalent (my tractor, my son's two electrical cars.) Sometimes these batteries seem to run down faster than expected. I would like to know the life I have left in these batteries with a quick look.

Is there something in between a Harbor Freight load tester and a high-end Torkel unit? I've never had much confidence in Harbor Freight even though there is one right around the corner from me. Most of their equipment is not what I consider "Porsche" quality. I wouldn't mind spending a few hundred dollars on a device that I can reliably tell my strength of all things battery (6V and 12V capacity).

Marc G.

IXLR8

OK, fill your boots and break out the wallet. Really, this is overkill for your use, trust me. I have a couple and lots of other top electronic test equipment in my lab at work.

Torkel - Programma

There is your problem.

I guarantee long battery life if:

• you use a quality battery
• your vehicle's charging system is spot on
• you never let it discharge and sit in that state
• all connections are in good condition

Heat and vibration shorten battery life.

Ten years out of a battery is easy. I'm in my fourteenth year now and it'll start tomorrow morning at -10F.


As for the electric cars, if the batteries are discharged, are they charged immediately...not a week later? Are the batteries chosen designed for deep discharge?

A conductance tester is a quick and dirty but not all that accurate way of determining battery health. I have one in the lab and have used it.

The HF unit is fine. I have the 500A and 100A units.

They do not have to be all that accurate. If you are load testing at 200A and it is actually 250A, no big deal. If you want accuracy, you can always get a lab grade current shunt and DMM to confirm.

d ward

All good advice, just one thing,i was lead to believe that you shouldn't use a carbon pile load tester on a modern lead acid battery ? the high load cause irreparably warping to the plates,seriously shortening the service life of the battery

IXLR8

Source? I never read that on any battery manufacturer's site. Or was that off some forum.

When you think about it, starting a car in sub-zero weather can draw a couple of hundred amps. I load test my daily driver car battery every couple of years and that battery is in its 14th year now.

d ward

What your saying makes sense.
Was just curious, it came written on a load of paperwork after i sent a week old varta battery that would not hold a charge, back to the shop three times, i had tested it twice on two high end bits of kit similar to the kit you used, the first couple of times they tested on a $100 tester and returned it saying it was fine, 3rd time they sent it away and said it must have been drop tested which damaged it, i hadn't as i certainly didn't drop test it. The forth & final time it went back was via the customer,thru the shops plate glass front door, guess he must of forgot to open it first ;-)

mgianzero

I give up! Battery dead again this morning. Just drove it 2 days ago. I was working on engine a bit yesterday and I even turned off the engine bay light but this morning there's just not enough juice to turn it over. Just clicks.

I charge it up with my Century charger and it seems to start again. Alternator seems fine as it registers 13.9-14.0 volts with car running. But if I leave the cabin light on with car off for just a little bit, the car doesn't seem to hold a charge. Like I said before, would be great to have a reliable and cost effective way to test the battery capacity and not just the voltage.

My records show that my battery (Interstate MTP-91 700 CCA / 875 CA) is 7 years old almost to the day. But Alex said he get's 10-15 years out of his batteries.

I live in warm southern California so there's not much cold to deal with. What am I doing wrong? Is it time up for my battery?. Would I be better off with a deep cell battery to give me a little more reserve? What does everyone recommend?

Marc G.

JGB

If by Deep Cell you mean Deep Cycle then you do not want this type of battery. Deep Cycle batteries are designed for light to moderate loads (current) such as operating lights etc in a RV and can be discharged almost to all of its capacity. The very high load of a starter will destroy such a battery very quickly.

Batteries for starting are designed to provided very high current for a relatively short time. They do not like to be completely discharged as this causes sulfation and internal failure. I recommend using a Battery Tender (or similar) if your car sits for any extended time. These devices are "smart" battery charges that provide different voltage/currents depending on the state of charge of the battery.

I think 7 years is a very old battery. If you charge it with it disconnected from the car does it hold the charge. If there are internal shorts the battery will discharge even if disconnected. If it holds the charge but then discharges when connected to the car then you have some sort of parasitic load. Lay people call these "shorts" but in reality a full short circuit will generally cause heat/fire. You may have some electronics staying on or a partial or resistive short of some sort.

On my boat I like to to replace the starting batteries every 3-4 years just because it can be a long paddle home otherwise.

Jim

IXLR8

Marc,

Without even testing it, I'd bet on a battery that needs replacing. But if you do want to perform some very simple tests...

Have you measured your standby current drain with everything off, that means ignition off, all lights (dome, glove, luggage and engine compartment) off?

It doesn't look like you want to take the time to take some measurements, so I would suggest fully charging the battery and then taking it in for a load test.

Voltage alone is just the first stage of a test. A load test tells you so much more. If your battery checks out, I would start checking wire connections and ground straps.

Cold temperatures are a challenge for a battery when it comes to starting. But heat shortens battery life.

If you didn't put much time into battery maintenance, then 7 years of service isn't all that bad. I do and get the years that I do out of mine.

pmalenfa

As mentioned, a 10+ years is possible providing ideal maintenance. But you are in hot weather, you drained the battery a few times (no trickle) and you rapid-recharged it as well. All those shorten the battery life and it's normal that your 7 years old battery is due.

If you really want to get a good tester, I would follow Alex advice for testing devices. I know a bit on this area but he seems to master it!

mgianzero

Alex,

I have a descent multitester. The voltage test is obvious. For the drain test, I disconnected my battery negative and connected my multimeter in series from ground cable to neg terminal with everything off and it doesn't seem to measure much of anything. Did I do that right?

Marc G.

IXLR8

Were you in DC amps mode and set to 200 mA (or similar).

Maybe you blew the fuse in the meter if it is reading 0. If your alarm is set, you should see less then 50 mA.

mgianzero

I thought I turned the amperage all the way down to measure mA and yes, I think I was in DC mode. But I'll look at it again this weekend. Perhaps I'll take a snapshot and send it to you.

Again, I'm learning.


Marc G.

mgianzero

Okay. So I'm trying to measure the standby current drain on my 911. Here's a snapshot of my multimeter that I was using. It looks as though it does DC amperage. But when I attach it to the car (between battery negative and ground cable) I read nothing.

What am I doing wrong?