I know this has been discussed here before, but I have to ask. I have a friend who has an 8 volt battery, and he wants to know what to use for charging. Six (6) is to low Twelve (12) is to high.
What is the best way
Thanks a bunch from, me and my friend.
The best way I've found is to use a 12 volt 6 or 8 amp charger and wire two 1156 bulbs in parallel in one of the charger's leads.
This gives some 3-4 amp charge BUT it will overcharge an 8 volt battery if you just leave it connected. Monitor the 8 volt battery's voltage and stop at between 9.6 and 10 volts.
Have a great evening,
Our 1919 touring, "Tin Tillie" and our 1917 Hupmobile "Whooper " both have 8 volt batteries in them when we get low at our shop, our rule of thumb is a 12 volt trickle charger, on 2 amps, for 2 hours. It puts the battery between 10.6 and 11.0 volts checked with a hand held voltage meter. One of our friends at our shop is an electrical engineer figured it out for us.
Why not just fix the vehicle, so it will start on a regular six bolt battery?
OR... three 8 volt batteries in series charged by two 12 volt chargers in series. Bit drastic though.
Don't understand the 9 to 11 volts from an 8 volt (4 cell) battery in previous posts. About the maximum voltage from a fully charged normal wet cell is 2.1 - 2.13 volts. Four cells would be 8.52 volts.
@Gary: The 9 - 11 volts are meassured during charging and represents that the battery is now fully charged.
The voltage in a running 12V system where the generator is charging is around 14,4V.
Some battery chargers have two charging voltage positions: A 6&8 volt position and a 12 volt position. I have one.
When you drive your car you are charging the battery with a 6 volt generator.
When you hook up a charger set it to 6 volts.
Why not buy an 8 volt battery charger?
A model T generator and a six-volt battery charger are two different animals.
You well know that a model T generator under no-load (zero current) can run-away with over-voltage. So, it can OVERCHARGE any battery from 6-12 volts.
A six-volt battery charger (mine, anyway) will not go past 7.5 volts.
My 12-volt one goes to 15.0 volts.
To fully-charge a lead acid battery, you want to charge to at least 2.4 volts per cell.
The six-volt battery chargers that I know of are not going to charge an 8-volt battery.
My 6 volt battery charger will charge the 8 volt battery that I have in one of my T's. Maybe some will not like the one Seth has but some evidently will.
I wish somebody had told me that a few years ago, I've been doing it for several years.
I have a 6 volt battery I use to start rebuilt engines when I am finished with them.
My little charger with the 6-8 volt switch seems to do the job just fine.
Since the battery goes dead just sitting by itself in 10 days I figure the charger must be doing its job.
Chargers can vary quite a bit in the quality of the DC voltage provided. The cheaper ones are only a transformer and rectifier resulting in a half wave AC. To see this switch to the AC scale. The more AC showing the poorer the effectiveness of the charger. Trying to measure this voltage using a DC scale meter will not give a true indication of the effective voltage being supplied.
Chargers are designed to provide a slightly higher voltage than the battery so complete charging can be accomplished. Consequently some chargers may put out enough extra to charge an 8 volt battery while others may not.
The better chargers will have filtering to give a charging voltage (and current)nearer to pure DC. Switching to the AC scale should show very little or no indication. Some chargers will have sensing to stop charging when the battery is fully charged preventing boil off of the electrolite. The better the charger the better the results leading to better battery life.
"The better the charger the better the results leading to better battery life."
I agree with you on the above statement but I need to point out that:
"The more powerful or the more expensive the charger - the better the charger is"
"the more fancy features, meters, bells, and whistles that a charger has - the better the charger is"
are both statements that are totally inaccurate.
I don't know if I've been lucky or stupid, but before I realized my car was 6 volt, I fully charged it with my 12 Volt Battery Tender brand charger.
It worked great. I expected an error when I found out it was 6 volt, since they sell a separate 6 volt charger.
It charges the 6 volt battery to 8 volts, then maintains it there. It's a dual charger...the same charger is hooked up to my '65 wildcat with the other set of leads.
Brian, to be perfectly FRANK with you you are not the Phirst one to charge a 6 volt battery with a 12 volt charger.
I won't mention his name but he posts on this site quite often.
And FRANKly he didn't hurt his battery either.