[Tom Wesenberg]

Batteries should be charged at no more than 10% of their rated amp hours, so if you have an 80 amp hour battery, you should limit the charge rate to 8 or fewer amps. I like these small 4 to 6 amp chargers, and they can be bought for less than $10 at swap meets. Just make sure the meter has numbers, so you can see what's actually happening.

This is one I bought a couple years ago for probably $3 or $4. It was a little beat looking and the charging cord was brittle with several cracks. The power cord was nice and flexible, but had one crack next to the cord lock, so I cut out the 1" where the wires were half broken, then spliced it just inside the case. The clamps were rusty, so for $1.45 I bought a new pair. Four feet cost 60 cents, the cord was 60 cents and the cord lock was 15 cents, so total cost except paint, which I already had, was $2.80, and with care this should last another 50 years.

For the charge cord I bought 6 feet of new wire at the surplus store, and a new pair of GB battery clamps at Menards. Two rubber feet were missing and the other two were cracked, so I bought new ones at the surplus store, as well as one missing cord lock for the charge cable. The main part of the case was a mess from someone setting it too close to the battery while it was charging, thus getting acid drops on it, so I sandblasted it and painted it blue. I used a paint brush to clean out the cob webs and thick layer of dust. I labeled the + and - inside the case to be sure the new charge cord didn't get mixed up.

I twisted the wires together, soldered them, then slipped heat shrink over them. Also notice the white heat shrink on the charge cord. I did this so the wire won't continue to pull apart after I pulled it apart for 9". I prefer to splice the wires just inside the case, rather than unsolder them at the component, as there is less chance of damaging a component, plus I gain a couple inches of wire length.

Notice the two selenium rectifiers riveted to the rear panel. Sometimes they can go bad, mostly from storing the charger in a damp place and letting it get rusty. If they go bad you can use diodes of high enough rating to replace them. If the transformer goes bad it isn't worth buying a new one, but do save the other parts as spares for another charger.

I'm not a fan of trickle chargers, but will use these for a light top off charge once in a while over the long winter storage.