Marithon jerking

[Helirich]

The cart works. But it seems slow. I checked the batteries and they all measure 6.1 Volts. Together they measure 36.4 Volts. I put it on charge. My batteries are old. What should they measure?

[JohnnieB]

Here is a SoC chart.

The voltages listed are measured about 12 hours after the charger shuts off automatically.

A fully charged battery (Trojan brand or clone) should read about 6.37V and a 36V pack of them should read about 38.2V.

[Helirich]

Thank you. I had it on charge last night. I'll check it today. What would you consider a dead battery after it has been charged? 60 percent?

[JohnnieB]

Originally Posted by Helirich

Thank you. I had it on charge last night. I'll check it today. What would you consider a dead battery after it has been charged? 60 percent?

In general terms, batteries reach the end of their useful life long before they die completely and only charging to about 60% SoC is a good indicator that a 7 year old battery has exceeded its useful lifespan.

However "Useful Lifespan" is open to interpretation since what is useful in some situations may not be useful in others.

If the pack voltage is low, the cart won't go very fast and if the amount of energy being stored isn't very much, the cart won't travel very far.

In the first post in this thread, you mentioned you only needed the cart too be usable for a few more weeks, so you might try charging the batteries back-to-back a few time to see if they will take more of a charge.

By back-to-back charging, I mean unplug the charger from the cart, wait a couple minutes and then plug it back into the cart, starting a new charge. I had pretty good results by doing that with a set of batteries that would only take an 85% charge when I got the cart and I used them over a year before I replaced them.

[Helirich]

Yea, I might do that. I was thinking of maybe charging them with a high quality 12volt charger, two at a time. This charger has a "renew" setting. I don't know what that means. But if it does anything, it would be better.

[Helirich]

So I put the charger on and it wasn't taking much charge. I put my 12volt charger on two of the batteries and they started taking 15 amps. So I'm going to charge it two at a time till its full.

The powerwise seems to work, but was only charging about 2-3 amps. Anybody run into that before? When it says 2 amps, does that mean 2 amps devided by all the batteries? Or is that 2amps in each battery. I seem to remember it jumping to like 12 amps before, but I'm not sure. Where is it supposed to charge at?

[JohnnieB]

The batteries are connected in series, so whatever is on the ammeter is going through all six batteries.

Powerwise makes (made) a lot of different chargers, the one pictured below was one of the more common types, does your charger look similar?

If so, it should put out in the 15A to 20A range when first connected.

[Helirich]

Mine looks like that except it has a knob on the front. You must turn the knob to get to to charge. It like a timer knob, except it has no marks and you can spin it all the way around till it goes off again. If you spin it 3/4 around, it ticks as it goes back to off.

Anyways for another stupid question that I should have asked before. If I hook a 12volt charger to two batteries in series, do I need to brake the link to the other 4 batteries?

[scottyb]

No, The 12v only effects the batteries between the 2 charge leads. So no need to remove any cables.

[JohnnieB]

There were two types of chargers with mechanical timers, one was purely mechanical and the other shut off when the pack voltage rose to a predetermined voltage. (The mechanical timer acted as a backup timer in case the voltage didn't get high enough in the allotted time.)

If there are no markings (Numbers) around the knob, I cannot tell which it is without looking inside, but that doesn't matter, when the charge first comes on, the amps ought to be above 15A and then start decreasing as the pack voltage climbs above about 42V. If not, either the capacitor connected to the transformer is bad, or the transformer is bad, or the diodes are bad. (Those three items is all there is to the actual battery charger, the rest of the stuff are bells and whistles.)

Attached is how to check the capacitor and transformer.

----------
If possible, post pictures of faceplate and innards of your charger.