Low end shake under load

[Gallachera89]

When climbing a small hill like a drive way or taking off full throttle it seems like the cart has a shutter or a shake to it.. kinda like a bad brush or a stuck brush.. but everything checks out and all the suspension is tight along with bearings

1989 club car ds, All new batteries (brute force 6v2000) new f/r switch, new cables between batteries(0g aircraft mill spec) new charge wires from port to batteries, pulled motor (D&D 170-004-0002a) apart and checked everything it looked fine, cleaned all connections and it still has a shake..

Since i have done the cables it inst as bad but when the batteries get a little bit of time on them its more noticeable..

need ideas here .. im gonna be replacing the other 7 large cables with the same aircraft cable i have between the batteries and see what happens

any ideas would be helpful, im gonna be getting a new solenoid soon and possibly a controller if i have to but from what i gathered i have a high amp one on already

Thanks again !

[joesam]

Shuddering under load is almost always a sign of low voltage in a series cart. Those batteries don't quite have the performance rating of their "gold standard" counterparts (Trojans). New or not - batteries can fail unexpectedly. Hook a digital voltmeter to each battery (one-at-a-time) after you have driven a couple miles. Then, go find a hill and drive up. I suspect at least one battery will dive in voltage - and you will have found your culprit.

Your statement

when the batteries get a little bit of time on them its more noticeable

suggests that is the issue.

[Gallachera89]

Originally Posted by joesam

Your statement suggests that is the issue.

Ill check it out.. i just bought the batteries like a week ago and they are all april of 2018 but i will load test them.. do you think maybe because i am running 36vs on a 48 volt motor will matter? i would just think i wont get the full potential out of it.. also i know the controller is good for both 36/48

[joesam]

because i am running 36vs on a 48 volt motor will matter

NOW THERE'S A PIECE OF INFORMATION THAT MATTERS! In a word - yes! I'm not a series motor expert, but that could be your only issue because the motor is so severely de-tuned at 36v (I'm thinking about the weak field coil more so than the armature).

[Gallachera89]

yah everything looked good in the motor..i have only had the cart a few weeks and ive been going after anything i can think of without having to buy more batteries .. this is my first cart by the way and my buddy who i got it from has had it for the past 15 years and sat for the last 5.. when i was a kid i would see him run this thing through the sand no problems and now im trying to mimic him and its not cutting it lol .. so i guess ill stuff a 12v in series one of these days and see if it comes alive.. but until then ill keep replacing wires and little things till its all new haha

[joesam]

stuff a 12v

uhmmmm...you are new. You will imbalance that pack and be dumping volts back and forth in the pack rather than achieve what you want. Think about your batteries like a chain (AKA weakest link etc). The chain must carry the load equally. If your budgeting, buy two more of those batteries and jam-'em'-in or carry two in the bag well. Charge those two separately with a 12v charger. You'll get longer duration on the whole pack and smooth delivery of voltage.

Again, I'm not an expert - but I'm old and semi-wise.

[Gallachera89]

yes im very new at this lol i do classic cars and atvs this is a new recent hobby

ill be damned.. well guess ill spend another 120 for 2 batteries and do that.. and you say with a 12v charger i can charge the 2 separate.... so i would hook them in series by themselves and hook positive to furthest and negative to furthest then i presume ?

guess that means ill have to unhook them every time i have to charge them correct unless i get a 48v charger and change the charge port?

[joesam]

You shouldn't have to unhook - make a big series loop - with your 36v charger terminating at the 36v point (6 batteries) - and the last two batteries at the end with their own 12v charger plug & wires. Draw it on paper - you'll see what I mean. Neither charger will "see" the other.

And golf carts are never grounded to the frame - it would be dangerous. So other than connecting to your drive system - the batteries are "floating" (probably not the right term, but you get the drift). There will be no accidental welding.

[Gallachera89]

well considering im no electrician i can not see what you mean .. i understand the concept in what you say and it will stop charging at 36vs but i cant picture how it would be wired.. and i know nothing is grounded to the frame i guess i worded it incorrectly

[Mooncarter]

You might as well go ahead and get a 48 volt charger and a 48 volt solenoid and get the 2 new batteries before they get thrown any further out of balance with the "old" ones.